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path: root/net/ipv4/inet_fragment.c
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2024-05-23net: Rename mono_delivery_time to tstamp_type for scalabiltyAbhishek Chauhan
mono_delivery_time was added to check if skb->tstamp has delivery time in mono clock base (i.e. EDT) otherwise skb->tstamp has timestamp in ingress and delivery_time at egress. Renaming the bitfield from mono_delivery_time to tstamp_type is for extensibilty for other timestamps such as userspace timestamp (i.e. SO_TXTIME) set via sock opts. As we are renaming the mono_delivery_time to tstamp_type, it makes sense to start assigning tstamp_type based on enum defined in this commit. Earlier we used bool arg flag to check if the tstamp is mono in function skb_set_delivery_time, Now the signature of the functions accepts tstamp_type to distinguish between mono and real time. Also skb_set_delivery_type_by_clockid is a new function which accepts clockid to determine the tstamp_type. In future tstamp_type:1 can be extended to support userspace timestamp by increasing the bitfield. Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-08inet: frags: delay fqdir_free_fn()Eric Dumazet
fqdir_free_fn() is using very expensive rcu_barrier() When one netns is dismantled, we often call fqdir_exit() multiple times, typically lauching fqdir_free_fn() twice. Delaying by one second fqdir_free_fn() helps to reduce the number of rcu_barrier() calls, and lock contention on rcu_state.barrier_mutex. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-28inet: inet_defrag: prevent sk release while still in useFlorian Westphal
ip_local_out() and other functions can pass skb->sk as function argument. If the skb is a fragment and reassembly happens before such function call returns, the sk must not be released. This affects skb fragments reassembled via netfilter or similar modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline. Eric Dumazet made an initial analysis of this bug. Quoting Eric: Calling ip_defrag() in output path is also implying skb_orphan(), which is buggy because output path relies on sk not disappearing. A relevant old patch about the issue was : 8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()") [..] net/ipv4/ip_output.c depends on skb->sk being set, and probably to an inet socket, not an arbitrary one. If we orphan the packet in ipvlan, then downstream things like FQ packet scheduler will not work properly. We need to change ip_defrag() to only use skb_orphan() when really needed, ie whenever frag_list is going to be used. Eric suggested to stash sk in fragment queue and made an initial patch. However there is a problem with this: If skb is refragmented again right after, ip_do_fragment() will copy head->sk to the new fragments, and sets up destructor to sock_wfree. IOW, we have no choice but to fix up sk_wmem accouting to reflect the fully reassembled skb, else wmem will underflow. This change moves the orphan down into the core, to last possible moment. As ip_defrag_offset is aliased with sk_buff->sk member, we must move the offset into the FRAG_CB, else skb->sk gets clobbered. This allows to delay the orphaning long enough to learn if the skb has to be queued or if the skb is completing the reasm queue. In the former case, things work as before, skb is orphaned. This is safe because skb gets queued/stolen and won't continue past reasm engine. In the latter case, we will steal the skb->sk reference, reattach it to the head skb, and fix up wmem accouting when inet_frag inflates truesize. Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().") Diagnosed-by: Eric Dumazet <edumazet@google.com> Reported-by: xingwei lee <xrivendell7@gmail.com> Reported-by: yue sun <samsun1006219@gmail.com> Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-10-31net: dropreason: add SKB_DROP_REASON_FRAG_REASM_TIMEOUTEric Dumazet
Used to track skbs freed after a timeout happened in a reassmbly unit. Passing a @reason argument to inet_frag_rbtree_purge() allows to use correct consumed status for frags that have been successfully re-assembled. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-30ipv4: remove unnecessary type castingsYu Zhe
remove unnecessary void* type castings. Signed-off-by: Yu Zhe <yuzhe@nfschina.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03net: ip: Handle delivery_time in ip defragMartin KaFai Lau
A latter patch will postpone the delivery_time clearing until the stack knows the skb is being delivered locally. That will allow other kernel forwarding path (e.g. ip[6]_forward) to keep the delivery_time also. An earlier attempt was to do skb_clear_delivery_time() in ip_local_deliver() and ip6_input(). The discussion [0] requested to move it one step later into ip_local_deliver_finish() and ip6_input_finish() so that the delivery_time can be kept for the ip_vs forwarding path also. To do that, this patch also needs to take care of the (rcv) timestamp usecase in ip_is_fragment(). It needs to expect delivery_time in the skb->tstamp, so it needs to save the mono_delivery_time bit in inet_frag_queue such that the delivery_time (if any) can be restored in the final defragmented skb. [Note that it will only happen when the locally generated skb is looping from egress to ingress over a virtual interface (e.g. veth, loopback...), skb->tstamp may have the delivery time before it is known that it will be delivered locally and received by another sk.] [0]: https://lore.kernel.org/netdev/ca728d81-80e8-3767-d5e-d44f6ad96e43@ssi.bg/ Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-13inet: frags: annotate races around fqdir->dead and fqdir->high_threshEric Dumazet
Both fields can be read/written without synchronization, add proper accessors and documentation. Fixes: d5dd88794a13 ("inet: fix various use-after-free in defrags units") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-12inet: frags: batch fqdir destroy worksSeongJae Park
On a few of our systems, I found frequent 'unshare(CLONE_NEWNET)' calls make the number of active slab objects including 'sock_inode_cache' type rapidly and continuously increase. As a result, memory pressure occurs. In more detail, I made an artificial reproducer that resembles the workload that we found the problem and reproduce the problem faster. It merely repeats 'unshare(CLONE_NEWNET)' 50,000 times in a loop. It takes about 2 minutes. On 40 CPU cores / 70GB DRAM machine, the available memory continuously reduced in a fast speed (about 120MB per second, 15GB in total within the 2 minutes). Note that the issue don't reproduce on every machine. On my 6 CPU cores machine, the problem didn't reproduce. 'cleanup_net()' and 'fqdir_work_fn()' are functions that deallocate the relevant memory objects. They are asynchronously invoked by the work queues and internally use 'rcu_barrier()' to ensure safe destructions. 'cleanup_net()' works in a batched maneer in a single thread worker, while 'fqdir_work_fn()' works for each 'fqdir_exit()' call in the 'system_wq'. Therefore, 'fqdir_work_fn()' called frequently under the workload and made the contention for 'rcu_barrier()' high. In more detail, the global mutex, 'rcu_state.barrier_mutex' became the bottleneck. This commit avoids such contention by doing the 'rcu_barrier()' and subsequent lightweight works in a batched manner, as similar to that of 'cleanup_net()'. The fqdir hashtable destruction, which is done before the 'rcu_barrier()', is still allowed to run in parallel for fast processing, but this commit makes it to use a dedicated work queue instead of the 'system_wq', to make sure that the number of threads is bounded. Signed-off-by: SeongJae Park <sjpark@amazon.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201211112405.31158-1-sjpark@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2019-08-08inet: frags: re-introduce skb coalescing for local deliveryGuillaume Nault
Before commit d4289fcc9b16 ("net: IP6 defrag: use rbtrees for IPv6 defrag"), a netperf UDP_STREAM test[0] using big IPv6 datagrams (thus generating many fragments) and running over an IPsec tunnel, reported more than 6Gbps throughput. After that patch, the same test gets only 9Mbps when receiving on a be2net nic (driver can make a big difference here, for example, ixgbe doesn't seem to be affected). By reusing the IPv4 defragmentation code, IPv6 lost fragment coalescing (IPv4 fragment coalescing was dropped by commit 14fe22e33462 ("Revert "ipv4: use skb coalescing in defragmentation"")). Without fragment coalescing, be2net runs out of Rx ring entries and starts to drop frames (ethtool reports rx_drops_no_frags errors). Since the netperf traffic is only composed of UDP fragments, any lost packet prevents reassembly of the full datagram. Therefore, fragments which have no possibility to ever get reassembled pile up in the reassembly queue, until the memory accounting exeeds the threshold. At that point no fragment is accepted anymore, which effectively discards all netperf traffic. When reassembly timeout expires, some stale fragments are removed from the reassembly queue, so a few packets can be received, reassembled and delivered to the netperf receiver. But the nic still drops frames and soon the reassembly queue gets filled again with stale fragments. These long time frames where no datagram can be received explain why the performance drop is so significant. Re-introducing fragment coalescing is enough to get the initial performances again (6.6Gbps with be2net): driver doesn't drop frames anymore (no more rx_drops_no_frags errors) and the reassembly engine works at full speed. This patch is quite conservative and only coalesces skbs for local IPv4 and IPv6 delivery (in order to avoid changing skb geometry when forwarding). Coalescing could be extended in the future if need be, as more scenarios would probably benefit from it. [0]: Test configuration Sender: ip xfrm policy flush ip xfrm state flush ip xfrm state add src fc00:1::1 dst fc00:2::1 proto esp spi 0x1000 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:1::1 dst fc00:2::1 ip xfrm policy add src fc00:1::1 dst fc00:2::1 dir in tmpl src fc00:1::1 dst fc00:2::1 proto esp mode transport action allow ip xfrm state add src fc00:2::1 dst fc00:1::1 proto esp spi 0x1001 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:2::1 dst fc00:1::1 ip xfrm policy add src fc00:2::1 dst fc00:1::1 dir out tmpl src fc00:2::1 dst fc00:1::1 proto esp mode transport action allow netserver -D -L fc00:2::1 Receiver: ip xfrm policy flush ip xfrm state flush ip xfrm state add src fc00:2::1 dst fc00:1::1 proto esp spi 0x1001 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:2::1 dst fc00:1::1 ip xfrm policy add src fc00:2::1 dst fc00:1::1 dir in tmpl src fc00:2::1 dst fc00:1::1 proto esp mode transport action allow ip xfrm state add src fc00:1::1 dst fc00:2::1 proto esp spi 0x1000 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:1::1 dst fc00:2::1 ip xfrm policy add src fc00:1::1 dst fc00:2::1 dir out tmpl src fc00:1::1 dst fc00:2::1 proto esp mode transport action allow netperf -H fc00:2::1 -f k -P 0 -L fc00:1::1 -l 60 -t UDP_STREAM -I 99,5 -i 5,5 -T5,5 -6 Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-24net/ipv4: cleanup error condition testingPavel Machek
Cleanup testing for error condition. Signed-off-by: Pavel Machek <pavel@denx.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19inet: fix various use-after-free in defrags unitsEric Dumazet
syzbot reported another issue caused by my recent patches. [1] The issue here is that fqdir_exit() is initiating a work queue and immediately returns. A bit later cleanup_net() was able to free the MIB (percpu data) and the whole struct net was freed, but we had active frag timers that fired and triggered use-after-free. We need to make sure that timers can catch fqdir->dead being set, to bailout. Since RCU is used for the reader side, this means we want to respect an RCU grace period between these operations : 1) qfdir->dead = 1; 2) netns dismantle (freeing of various data structure) This patch uses new new (struct pernet_operations)->pre_exit infrastructure to ensures a full RCU grace period happens between fqdir_pre_exit() and fqdir_exit() This also means we can use a regular work queue, we no longer need rcu_work. Tested: $ time for i in {1..1000}; do unshare -n /bin/false;done real 0m2.585s user 0m0.160s sys 0m2.214s [1] BUG: KASAN: use-after-free in ip_expire+0x73e/0x800 net/ipv4/ip_fragment.c:152 Read of size 8 at addr ffff88808b9fe330 by task syz-executor.4/11860 CPU: 1 PID: 11860 Comm: syz-executor.4 Not tainted 5.2.0-rc2+ #22 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ip_expire+0x73e/0x800 net/ipv4/ip_fragment.c:152 call_timer_fn+0x193/0x720 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x66f/0x1740 kernel/time/timer.c:1698 __do_softirq+0x25c/0x94c kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 </IRQ> RIP: 0010:tomoyo_domain_quota_is_ok+0x131/0x540 security/tomoyo/util.c:1035 Code: 24 4c 3b 65 d0 0f 84 9c 00 00 00 e8 19 1d 73 fe 49 8d 7c 24 18 48 ba 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 0f b6 04 10 <48> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 69 03 00 00 41 0f b6 5c RSP: 0018:ffff88806ae079c0 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000010 RCX: ffffc9000e655000 RDX: dffffc0000000000 RSI: ffffffff82fd88a7 RDI: ffff888086202398 RBP: ffff88806ae07a00 R08: ffff88808b6c8700 R09: ffffed100d5c0f4d R10: ffffed100d5c0f4c R11: 0000000000000000 R12: ffff888086202380 R13: 0000000000000030 R14: 00000000000000d3 R15: 0000000000000000 tomoyo_supervisor+0x2e8/0xef0 security/tomoyo/common.c:2087 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline] tomoyo_path_number_perm+0x42f/0x520 security/tomoyo/file.c:734 tomoyo_file_ioctl+0x23/0x30 security/tomoyo/tomoyo.c:335 security_file_ioctl+0x77/0xc0 security/security.c:1370 ksys_ioctl+0x57/0xd0 fs/ioctl.c:711 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f8db5e44c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004592c9 RDX: 0000000020000080 RSI: 00000000000089f1 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8db5e456d4 R13: 00000000004cc770 R14: 00000000004d5cd8 R15: 00000000ffffffff Allocated by task 9047: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 kmem_cache_zalloc include/linux/slab.h:732 [inline] net_alloc net/core/net_namespace.c:386 [inline] copy_net_ns+0xed/0x340 net/core/net_namespace.c:426 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2692 __do_sys_unshare kernel/fork.c:2760 [inline] __se_sys_unshare kernel/fork.c:2758 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2758 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2541: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 net_free net/core/net_namespace.c:402 [inline] net_drop_ns.part.0+0x70/0x90 net/core/net_namespace.c:409 net_drop_ns net/core/net_namespace.c:408 [inline] cleanup_net+0x538/0x960 net/core/net_namespace.c:571 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88808b9fe100 which belongs to the cache net_namespace of size 6784 The buggy address is located 560 bytes inside of 6784-byte region [ffff88808b9fe100, ffff88808b9ffb80) The buggy address belongs to the page: page:ffffea00022e7f80 refcount:1 mapcount:0 mapping:ffff88821b6f60c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea000256f288 ffffea0001bbef08 ffff88821b6f60c0 raw: 0000000000000000 ffff88808b9fe100 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808b9fe200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b9fe280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808b9fe300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808b9fe380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b9fe400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 3c8fc8782044 ("inet: frags: rework rhashtable dismantle") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30inet: frags: Remove unnecessary smp_store_release/READ_ONCEHerbert Xu
The smp_store_release call in fqdir_exit cannot protect the setting of fqdir->dead as claimed because its memory barrier is only guaranteed to be one-way and the barrier precedes the setting of fqdir->dead. IOW it doesn't provide any barriers between fq->dir and the following hash table destruction. In fact, the code is safe anyway because call_rcu does provide both the memory barrier as well as a guarantee that when the destruction work starts executing all RCU readers will see the updated value for fqdir->dead. Therefore this patch removes the unnecessary smp_store_release call as well as the corresponding READ_ONCE on the read-side in order to not confuse future readers of this code. Comments have been added in their places. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-28inet: frags: fix use-after-free read in inet_frag_destroy_rcuEric Dumazet
As caught by syzbot [1], the rcu grace period that is respected before fqdir_rwork_fn() proceeds and frees fqdir is not enough to prevent inet_frag_destroy_rcu() being run after the freeing. We need a proper rcu_barrier() synchronization to replace the one we had in inet_frags_fini() We also have to fix a potential problem at module removal : inet_frags_fini() needs to make sure that all queued work queues (fqdir_rwork_fn) have completed, otherwise we might call kmem_cache_destroy() too soon and get another use-after-free. [1] BUG: KASAN: use-after-free in inet_frag_destroy_rcu+0xd9/0xe0 net/ipv4/inet_fragment.c:201 Read of size 8 at addr ffff88806ed47a18 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.2.0-rc1+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 inet_frag_destroy_rcu+0xd9/0xe0 net/ipv4/inet_fragment.c:201 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0xba5/0x1500 kernel/rcu/tree.c:2291 __do_softirq+0x25c/0x94c kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 </IRQ> RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: ff ff 48 89 df e8 f2 95 8c fa eb 82 e9 07 00 00 00 0f 00 2d e4 45 4b 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d d4 45 4b 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 8e 18 42 fa e8 99 RSP: 0018:ffff8880a98e7d78 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1164e11 RBX: ffff8880a98d4340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a98d4bbc RBP: ffff8880a98e7da8 R08: ffff8880a98d4340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff88b27078 R14: 0000000000000001 R15: 0000000000000000 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x36/0x90 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x377/0x560 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354 start_secondary+0x34e/0x4c0 arch/x86/kernel/smpboot.c:267 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Allocated by task 8877: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 kmem_cache_alloc_trace+0x151/0x750 mm/slab.c:3555 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:742 [inline] fqdir_init include/net/inet_frag.h:115 [inline] ipv6_frags_init_net+0x48/0x460 net/ipv6/reassembly.c:513 ops_init+0xb3/0x410 net/core/net_namespace.c:130 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2692 __do_sys_unshare kernel/fork.c:2760 [inline] __se_sys_unshare kernel/fork.c:2758 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2758 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 17: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 fqdir_rwork_fn+0x33/0x40 net/ipv4/inet_fragment.c:154 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88806ed47a00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of 512-byte region [ffff88806ed47a00, ffff88806ed47c00) The buggy address belongs to the page: page:ffffea0001bb51c0 refcount:1 mapcount:0 mapping:ffff8880aa400940 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea000282a788 ffffea0001bb53c8 ffff8880aa400940 raw: 0000000000000000 ffff88806ed47000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806ed47900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806ed47980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88806ed47a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806ed47a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806ed47b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 3c8fc8782044 ("inet: frags: rework rhashtable dismantle") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-28inet: frags: uninline fqdir_init()Eric Dumazet
fqdir_init() is not fast path and is getting bigger. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-26inet: frags: rework rhashtable dismantleEric Dumazet
syszbot found an interesting use-after-free [1] happening while IPv4 fragment rhashtable was destroyed at netns dismantle. While no insertions can possibly happen at the time a dismantling netns is destroying this rhashtable, timers can still fire and attempt to remove elements from this rhashtable. This is forbidden, since rhashtable_free_and_destroy() has no synchronization against concurrent inserts and deletes. Add a new fqdir->dead flag so that timers do not attempt a rhashtable_remove_fast() operation. We also have to respect an RCU grace period before starting the rhashtable_free_and_destroy() from process context, thus we use rcu_work infrastructure. This is a refinement of a prior rough attempt to fix this bug : https://marc.info/?l=linux-netdev&m=153845936820900&w=2 Since the rhashtable cleanup is now deferred to a work queue, netns dismantles should be slightly faster. [1] BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:194 [inline] BUG: KASAN: use-after-free in rhashtable_last_table+0x162/0x180 lib/rhashtable.c:212 Read of size 8 at addr ffff8880a6497b70 by task kworker/0:0/5 CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.2.0-rc1+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events rht_deferred_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __read_once_size include/linux/compiler.h:194 [inline] rhashtable_last_table+0x162/0x180 lib/rhashtable.c:212 rht_deferred_worker+0x111/0x2030 lib/rhashtable.c:411 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 32687: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc_node mm/slab.c:3620 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3627 kmalloc_node include/linux/slab.h:590 [inline] kvmalloc_node+0x68/0x100 mm/util.c:431 kvmalloc include/linux/mm.h:637 [inline] kvzalloc include/linux/mm.h:645 [inline] bucket_table_alloc+0x90/0x480 lib/rhashtable.c:178 rhashtable_init+0x3f4/0x7b0 lib/rhashtable.c:1057 inet_frags_init_net include/net/inet_frag.h:109 [inline] ipv4_frags_init_net+0x182/0x410 net/ipv4/ip_fragment.c:683 ops_init+0xb3/0x410 net/core/net_namespace.c:130 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2692 __do_sys_unshare kernel/fork.c:2760 [inline] __se_sys_unshare kernel/fork.c:2758 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2758 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 kvfree+0x61/0x70 mm/util.c:460 bucket_table_free+0x69/0x150 lib/rhashtable.c:108 rhashtable_free_and_destroy+0x165/0x8b0 lib/rhashtable.c:1155 inet_frags_exit_net+0x3d/0x50 net/ipv4/inet_fragment.c:152 ipv4_frags_exit_net+0x73/0x90 net/ipv4/ip_fragment.c:695 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:154 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:553 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8880a6497b40 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 48 bytes inside of 1024-byte region [ffff8880a6497b40, ffff8880a6497f40) The buggy address belongs to the page: page:ffffea0002992580 refcount:1 mapcount:0 mapping:ffff8880aa400ac0 index:0xffff8880a64964c0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002916e88 ffffea000218fe08 ffff8880aa400ac0 raw: ffff8880a64964c0 ffff8880a6496040 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6497a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a6497a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880a6497b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880a6497b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a6497c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-26net: dynamically allocate fqdir structuresEric Dumazet
Following patch will add rcu grace period before fqdir rhashtable destruction, so we need to dynamically allocate fqdir structures to not force expensive synchronize_rcu() calls in netns dismantle path. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-26net: rename inet_frags_exit_net() to fqdir_exit()Eric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-26inet: rename netns_frags to fqdirEric Dumazet
1) struct netns_frags is renamed to struct fqdir This structure is really holding many frag queues in a hash table. 2) (struct inet_frag_queue)->net field is renamed to fqdir since net is generally associated to a 'struct net' pointer in networking stack. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-26net: remove unused struct inet_frag_queue.fragments fieldPeter Oskolkov
Now that all users of struct inet_frag_queue have been converted to use 'rb_fragments', remove the unused 'fragments' field. Build with `make allyesconfig` succeeded. ip_defrag selftest passed. Signed-off-by: Peter Oskolkov <posk@google.com> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-25net: IP defrag: encapsulate rbtree defrag code into callable functionsPeter Oskolkov
This is a refactoring patch: without changing runtime behavior, it moves rbtree-related code from IPv4-specific files/functions into .h/.c defrag files shared with IPv6 defragmentation code. Signed-off-by: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08inet: frags: better deal with smp racesEric Dumazet
Multiple cpus might attempt to insert a new fragment in rhashtable, if for example RPS is buggy, as reported by 배석진 in https://patchwork.ozlabs.org/patch/994601/ We use rhashtable_lookup_get_insert_key() instead of rhashtable_insert_fast() to let cpus losing the race free their own inet_frag_queue and use the one that was inserted by another cpu. Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: 배석진 <soukjin.bae@samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11ip: process in-order fragments efficientlyPeter Oskolkov
This patch changes the runtime behavior of IP defrag queue: incoming in-order fragments are added to the end of the current list/"run" of in-order fragments at the tail. On some workloads, UDP stream performance is substantially improved: RX: ./udp_stream -F 10 -T 2 -l 60 TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60 with this patchset applied on a 10Gbps receiver: throughput=9524.18 throughput_units=Mbit/s upstream (net-next): throughput=4608.93 throughput_units=Mbit/s Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05ip: use rb trees for IP frag queue.Peter Oskolkov
Similar to TCP OOO RX queue, it makes sense to use rb trees to store IP fragments, so that OOO fragments are inserted faster. Tested: - a follow-up patch contains a rather comprehensive ip defrag self-test (functional) - ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`: netstat --statistics Ip: 282078937 total packets received 0 forwarded 0 incoming packets discarded 946760 incoming packets delivered 18743456 requests sent out 101 fragments dropped after timeout 282077129 reassemblies required 944952 packets reassembled ok 262734239 packet reassembles failed (The numbers/stats above are somewhat better re: reassemblies vs a kernel without this patchset. More comprehensive performance testing TBD). Reported-by: Jann Horn <jannh@google.com> Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The BTF conflicts were simple overlapping changes. The virtio_net conflict was an overlap of a fix of statistics counter, happening alongisde a move over to a bonafide statistics structure rather than counting value on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-31inet: frag: enforce memory limits earlierEric Dumazet
We currently check current frags memory usage only when a new frag queue is created. This allows attackers to first consume the memory budget (default : 4 MB) creating thousands of frag queues, then sending tiny skbs to exceed high_thresh limit by 2 to 3 order of magnitude. Note that before commit 648700f76b03 ("inet: frags: use rhashtables for reassembly units"), work queue could be starved under DOS, getting no cpu cycles. After commit 648700f76b03, only the per frag queue timer can eventually remove an incomplete frag queue and its skbs. Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jann Horn <jannh@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Peter Oskolkov <posk@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linuxDavid S. Miller
All conflicts were trivial overlapping changes, so reasonably easy to resolve. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08ipfrag: really prevent allocation on netns exitPaolo Abeni
Setting the low threshold to 0 has no effect on frags allocation, we need to clear high_thresh instead. The code was pre-existent to commit 648700f76b03 ("inet: frags: use rhashtables for reassembly units"), but before the above, such assignment had a different role: prevent concurrent eviction from the worker and the netns cleanup helper. Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-22rhashtable: split rhashtable.hNeilBrown
Due to the use of rhashtables in net namespaces, rhashtable.h is included in lots of the kernel, so a small changes can required a large recompilation. This makes development painful. This patch splits out rhashtable-types.h which just includes the major type declarations, and does not include (non-trivial) inline code. rhashtable.h is no longer included by anything in the include/ directory. Common include files only include rhashtable-types.h so a large recompilation is only triggered when that changes. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: remove inet_frag_maybe_warn_overflow()Eric Dumazet
This function is obsolete, after rhashtable addition to inet defrag. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: use rhashtables for reassembly unitsEric Dumazet
Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: add a pointer to struct netns_fragsEric Dumazet
In order to simplify the API, add a pointer to struct inet_frags. This will allow us to make things less complex. These functions no longer have a struct inet_frags parameter : inet_frag_destroy(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */) ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07net: Fix hlist corruptions in inet_evict_bucket()Kirill Tkhai
inet_evict_bucket() iterates global list, and several tasks may call it in parallel. All of them hash the same fq->list_evictor to different lists, which leads to list corruption. This patch makes fq be hashed to expired list only if this has not been made yet by another task. Since inet_frag_alloc() allocates fq using kmem_cache_zalloc(), we may rely on list_evictor is initially unhashed. The problem seems to exist before async pernet_operations, as there was possible to have exit method to be executed in parallel with inet_frags::frags_work, so I add two Fixes tags. This also may go to stable. Fixes: d1fe19444d82 "inet: frag: don't re-use chainlist for evictor" Fixes: f84c6821aa54 "net: Convert pernet_subsys, registered from inet_init()" Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Highlights: 1) Maintain the TCP retransmit queue using an rbtree, with 1GB windows at 100Gb this really has become necessary. From Eric Dumazet. 2) Multi-program support for cgroup+bpf, from Alexei Starovoitov. 3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew Lunn. 4) Add meter action support to openvswitch, from Andy Zhou. 5) Add a data meta pointer for BPF accessible packets, from Daniel Borkmann. 6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet. 7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli. 8) More work to move the RTNL mutex down, from Florian Westphal. 9) Add 'bpftool' utility, to help with bpf program introspection. From Jakub Kicinski. 10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper Dangaard Brouer. 11) Support 'blocks' of transformations in the packet scheduler which can span multiple network devices, from Jiri Pirko. 12) TC flower offload support in cxgb4, from Kumar Sanghvi. 13) Priority based stream scheduler for SCTP, from Marcelo Ricardo Leitner. 14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg. 15) Add RED qdisc offloadability, and use it in mlxsw driver. From Nogah Frankel. 16) eBPF based device controller for cgroup v2, from Roman Gushchin. 17) Add some fundamental tracepoints for TCP, from Song Liu. 18) Remove garbage collection from ipv6 route layer, this is a significant accomplishment. From Wei Wang. 19) Add multicast route offload support to mlxsw, from Yotam Gigi" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits) tcp: highest_sack fix geneve: fix fill_info when link down bpf: fix lockdep splat net: cdc_ncm: GetNtbFormat endian fix openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start netem: remove unnecessary 64 bit modulus netem: use 64 bit divide by rate tcp: Namespace-ify sysctl_tcp_default_congestion_control net: Protect iterations over net::fib_notifier_ops in fib_seq_sum() ipv6: set all.accept_dad to 0 by default uapi: fix linux/tls.h userspace compilation error usbnet: ipheth: prevent TX queue timeouts when device not ready vhost_net: conditionally enable tx polling uapi: fix linux/rxrpc.h userspace compilation errors net: stmmac: fix LPI transitioning for dwmac4 atm: horizon: Fix irq release error net-sysfs: trigger netlink notification on ifalias change via sysfs openvswitch: Using kfree_rcu() to simplify the code openvswitch: Make local function ovs_nsh_key_attr_size() static openvswitch: Fix return value check in ovs_meter_cmd_features() ...
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18inet: frags: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: Florian Westphal <fw@strlen.de> Cc: linux-wpan@vger.kernel.org Cc: netdev@vger.kernel.org Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Stefan Schmidt <stefan@osg.samsung.com> # for ieee802154 Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03Revert "net: use lib/percpu_counter API for fragmentation mem accounting"Jesper Dangaard Brouer
This reverts commit 6d7b857d541ecd1d9bd997c97242d4ef94b19de2. There is a bug in fragmentation codes use of the percpu_counter API, that can cause issues on systems with many CPUs. The frag_mem_limit() just reads the global counter (fbc->count), without considering other CPUs can have upto batch size (130K) that haven't been subtracted yet. Due to the 3MBytes lower thresh limit, this become dangerous at >=24 CPUs (3*1024*1024/130000=24). The correct API usage would be to use __percpu_counter_compare() which does the right thing, and takes into account the number of (online) CPUs and batch size, to account for this and call __percpu_counter_sum() when needed. We choose to revert the use of the lib/percpu_counter API for frag memory accounting for several reasons: 1) On systems with CPUs > 24, the heavier fully locked __percpu_counter_sum() is always invoked, which will be more expensive than the atomic_t that is reverted to. Given systems with more than 24 CPUs are becoming common this doesn't seem like a good option. To mitigate this, the batch size could be decreased and thresh be increased. 2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX CPU, before SKBs are pushed into sockets on remote CPUs. Given NICs can only hash on L2 part of the IP-header, the NIC-RXq's will likely be limited. Thus, a fair chance that atomic add+dec happen on the same CPU. Revert note that commit 1d6119baf061 ("net: fix percpu memory leaks") removed init_frag_mem_limit() and instead use inet_frags_init_net(). After this revert, inet_frags_uninit_net() becomes empty. Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting") Fixes: 1d6119baf061 ("net: fix percpu memory leaks") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert inet_frag_queue.refcnt from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-05net: disable fragment reassembly if high_thresh is zeroMichal Kubeček
Before commit 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting"), setting the reassembly high threshold to 0 prevented fragment reassembly as first fragment would be always evicted before second could be added to the queue. While inefficient, some users apparently relied on this method. Since the commit mentioned above, a percpu counter is used for reassembly memory accounting and high batch size avoids taking slow path in most common scenarios. As a result, a whole full sized packet can be reassembled without the percpu counter's main counter changing its value so that even with high_thresh set to 0, fragmented packets can be still reassembled and processed. Add explicit check preventing reassembly if high threshold is zero. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05inet: kill unused skb_free opFlorian Westphal
The only user was removed in commit 029f7f3b8701cc7a ("netfilter: ipv6: nf_defrag: avoid/free clone operations"). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-02net: fix percpu memory leaksEric Dumazet
This patch fixes following problems : 1) percpu_counter_init() can return an error, therefore init_frag_mem_limit() must propagate this error so that inet_frags_init_net() can do the same up to its callers. 2) If ip[46]_frags_ns_ctl_register() fail, we must unwind properly and free the percpu_counter. Without this fix, we leave freed object in percpu_counters global list (if CONFIG_HOTPLUG_CPU) leading to crashes. This bug was detected by KASAN and syzkaller tool (http://github.com/google/syzkaller) Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the testNikolay Aleksandrov
We can simply remove the INET_FRAG_EVICTED flag to avoid all the flags race conditions with the evictor and use a participation test for the evictor list, when we're at that point (after inet_frag_kill) in the timer there're 2 possible cases: 1. The evictor added the entry to its evictor list while the timer was waiting for the chainlock or 2. The timer unchained the entry and the evictor won't see it In both cases we should be able to see list_evictor correctly due to the sync on the chainlock. Joint work with Florian Westphal. Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: don't wait for timer deletion when evictingFlorian Westphal
Frank reports 'NMI watchdog: BUG: soft lockup' errors when load is high. Instead of (potentially) unbounded restarts of the eviction process, just skip to the next entry. One caveat is that, when a netns is exiting, a timer may still be running by the time inet_evict_bucket returns. We use the frag memory accounting to wait for outstanding timers, so that when we free the percpu counter we can be sure no running timer will trip over it. Reported-and-tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: change *_frag_mem_limit functions to take netns_frags as argumentFlorian Westphal
Followup patch will call it after inet_frag_queue was freed, so q->net doesn't work anymore (but netf = q->net; free(q); mem_limit(netf) would). Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: don't re-use chainlist for evictorFlorian Westphal
commit 65ba1f1ec0eff ("inet: frags: fix a race between inet_evict_bucket and inet_frag_kill") describes the bug, but the fix doesn't work reliably. Problem is that ->flags member can be set on other cpu without chainlock being held by that task, i.e. the RMW-Cycle can clear INET_FRAG_EVICTED bit after we put the element on the evictor private list. We can crash when walking the 'private' evictor list since an element can be deleted from list underneath the evictor. Join work with Nikolay Alexandrov. Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Reported-by: Johan Schuijt <johan@transip.nl> Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Nikolay Alexandrov <nikolay@cumulusnetworks.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03ipv4: coding style: comparison for equality with NULLIan Morris
The ipv4 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris <ipm@chirality.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-11net: Convert LIMIT_NETDEBUG to net_dbg_ratelimitedJoe Perches
Use the more common dynamic_debug capable net_dbg_ratelimited and remove the LIMIT_NETDEBUG macro. All messages are still ratelimited. Some KERN_<LEVEL> uses are changed to KERN_DEBUG. This may have some negative impact on messages that were emitted at KERN_INFO that are not not enabled at all unless DEBUG is defined or dynamic_debug is enabled. Even so, these messages are now _not_ emitted by default. This also eliminates the use of the net_msg_warn sysctl "/proc/sys/net/core/warnings". For backward compatibility, the sysctl is not removed, but it has no function. The extern declaration of net_msg_warn is removed from sock.h and made static in net/core/sysctl_net_core.c Miscellanea: o Update the sysctl documentation o Remove the embedded uses of pr_fmt o Coalesce format fragments o Realign arguments Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-29inet: frags: remove the WARN_ON from inet_evict_bucketNikolay Aleksandrov
The WARN_ON in inet_evict_bucket can be triggered by a valid case: inet_frag_kill and inet_evict_bucket can be running in parallel on the same queue which means that there has been at least one more ref added by a previous inet_frag_find call, but inet_frag_kill can delete the timer before inet_evict_bucket which will cause the WARN_ON() there to trigger since we'll have refcnt!=1. Now, this case is valid because the queue is being "killed" for some reason (removed from the chain list and its timer deleted) so it will get destroyed in the end by one of the inet_frag_put() calls which reaches 0 i.e. refcnt is still valid. CC: Florian Westphal <fw@strlen.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McLean <chutzpah@gentoo.org> Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Reported-by: Patrick McLean <chutzpah@gentoo.org> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-29inet: frags: fix a race between inet_evict_bucket and inet_frag_killNikolay Aleksandrov
When the evictor is running it adds some chosen frags to a local list to be evicted once the chain lock has been released but at the same time the *frag_queue can be running for some of the same queues and it may call inet_frag_kill which will wait on the chain lock and will then delete the queue from the wrong list since it was added in the eviction one. The fix is simple - check if the queue has the evict flag set under the chain lock before deleting it, this is safe because the evict flag is set only under that lock and having the flag set also means that the queue has been detached from the chain list, so no need to delete it again. An important note to make is that we're safe w.r.t refcnt because inet_frag_kill and inet_evict_bucket will sync on the del_timer operation where only one of the two can succeed (or if the timer is executing - none of them), the cases are: 1. inet_frag_kill succeeds in del_timer - then the timer ref is removed, but inet_evict_bucket will not add this queue to its expire list but will restart eviction in that chain 2. inet_evict_bucket succeeds in del_timer - then the timer ref is kept until the evictor "expires" the queue, but inet_frag_kill will remove the initial ref and will set INET_FRAG_COMPLETE which will make the frag_expire fn just to remove its ref. In the end all of the queue users will do an inet_frag_put and the one that reaches 0 will free it. The refcount balance should be okay. CC: Florian Westphal <fw@strlen.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McLean <chutzpah@gentoo.org> Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Patrick McLean <chutzpah@gentoo.org> Tested-by: Patrick McLean <chutzpah@gentoo.org> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>