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2023-01-24netrom: Fix use-after-free of a listening socket.Kuniyuki Iwashima
syzbot reported a use-after-free in do_accept(), precisely nr_accept() as sk_prot_alloc() allocated the memory and sock_put() frees it. [0] The issue could happen if the heartbeat timer is fired and nr_heartbeat_expiry() calls nr_destroy_socket(), where a socket has SOCK_DESTROY or a listening socket has SOCK_DEAD. In this case, the first condition cannot be true. SOCK_DESTROY is flagged in nr_release() only when the file descriptor is close()d, but accept() is being called for the listening socket, so the second condition must be true. Usually, the AF_NETROM listener neither starts timers nor sets SOCK_DEAD. However, the condition is met if connect() fails before listen(). connect() starts the t1 timer and heartbeat timer, and t1timer calls nr_disconnect() when timeout happens. Then, SOCK_DEAD is set, and if we call listen(), the heartbeat timer calls nr_destroy_socket(). nr_connect nr_establish_data_link(sk) nr_start_t1timer(sk) nr_start_heartbeat(sk) nr_t1timer_expiry nr_disconnect(sk, ETIMEDOUT) nr_sk(sk)->state = NR_STATE_0 sk->sk_state = TCP_CLOSE sock_set_flag(sk, SOCK_DEAD) nr_listen if (sk->sk_state != TCP_LISTEN) sk->sk_state = TCP_LISTEN nr_heartbeat_expiry switch (nr->state) case NR_STATE_0 if (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD)) nr_destroy_socket(sk) This path seems expected, and nr_destroy_socket() is called to clean up resources. Initially, there was sock_hold() before nr_destroy_socket() so that the socket would not be freed, but the commit 517a16b1a88b ("netrom: Decrease sock refcount when sock timers expire") accidentally removed it. To fix use-after-free, let's add sock_hold(). [0]: BUG: KASAN: use-after-free in do_accept+0x483/0x510 net/socket.c:1848 Read of size 8 at addr ffff88807978d398 by task syz-executor.3/5315 CPU: 0 PID: 5315 Comm: syz-executor.3 Not tainted 6.2.0-rc3-syzkaller-00165-gd9fc1511728c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x461 mm/kasan/report.c:417 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 do_accept+0x483/0x510 net/socket.c:1848 __sys_accept4_file net/socket.c:1897 [inline] __sys_accept4+0x9a/0x120 net/socket.c:1927 __do_sys_accept net/socket.c:1944 [inline] __se_sys_accept net/socket.c:1941 [inline] __x64_sys_accept+0x75/0xb0 net/socket.c:1941 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa436a8c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa437784168 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: ffffffffffffffda RBX: 00007fa436bac050 RCX: 00007fa436a8c0c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fa436ae7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffebc6700df R14: 00007fa437784300 R15: 0000000000022000 </TASK> Allocated by task 5294: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa3/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:968 [inline] __kmalloc+0x5a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] sk_prot_alloc+0x140/0x290 net/core/sock.c:2038 sk_alloc+0x3a/0x7a0 net/core/sock.c:2091 nr_create+0xb6/0x5f0 net/netrom/af_netrom.c:433 __sock_create+0x359/0x790 net/socket.c:1515 sock_create net/socket.c:1566 [inline] __sys_socket_create net/socket.c:1603 [inline] __sys_socket_create net/socket.c:1588 [inline] __sys_socket+0x133/0x250 net/socket.c:1636 __do_sys_socket net/socket.c:1649 [inline] __se_sys_socket net/socket.c:1647 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 14: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] __cache_free mm/slab.c:3394 [inline] __do_kmem_cache_free mm/slab.c:3580 [inline] __kmem_cache_free+0xcd/0x3b0 mm/slab.c:3587 sk_prot_free net/core/sock.c:2074 [inline] __sk_destruct+0x5df/0x750 net/core/sock.c:2166 sk_destruct net/core/sock.c:2181 [inline] __sk_free+0x175/0x460 net/core/sock.c:2192 sk_free+0x7c/0xa0 net/core/sock.c:2203 sock_put include/net/sock.h:1991 [inline] nr_heartbeat_expiry+0x1d7/0x460 net/netrom/nr_timer.c:148 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1700 expire_timers+0x2c6/0x5c0 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 Fixes: 517a16b1a88b ("netrom: Decrease sock refcount when sock timers expire") Reported-by: syzbot+5fafd5cfe1fc91f6b352@syzkaller.appspotmail.com Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230120231927.51711-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2021-07-18netrom: Decrease sock refcount when sock timers expireNguyen Dinh Phi
Commit 63346650c1a9 ("netrom: switch to sock timer API") switched to use sock timer API. It replaces mod_timer() by sk_reset_timer(), and del_timer() by sk_stop_timer(). Function sk_reset_timer() will increase the refcount of sock if it is called on an inactive timer, hence, in case the timer expires, we need to decrease the refcount ourselves in the handler, otherwise, the sock refcount will be unbalanced and the sock will never be freed. Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com> Reported-by: syzbot+10f1194569953b72f1ae@syzkaller.appspotmail.com Fixes: 63346650c1a9 ("netrom: switch to sock timer API") 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>
2019-01-27netrom: switch to sock timer APICong Wang
sk_reset_timer() and sk_stop_timer() properly handle sock refcnt for timer function. Switching to them could fix a refcounting bug reported by syzbot. Reported-and-tested-by: syzbot+defa700d16f1bd1b9a05@syzkaller.appspotmail.com Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-hams@vger.kernel.org Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-21treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE castsKees Cook
With all callbacks converted, and the timer callback prototype switched over, the TIMER_FUNC_TYPE cast is no longer needed, so remove it. Conversion was done with the following scripts: perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \ $(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u) perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \ $(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u) The now unused macros are also dropped from include/linux/timer.h. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-18net/core: Convert sk_timer users 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 for all users of sk_timer. Cc: "David S. Miller" <davem@davemloft.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: linzhang <xiaolou4617@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-hams@vger.kernel.org Cc: linux-x25@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18net/core: Collapse redundant sk_timer callback data assignmentsKees Cook
The core sk_timer initializer can provide the common .data assignment instead of it being set separately in users. Cc: "David S. Miller" <davem@davemloft.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: linzhang <xiaolou4617@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-hams@vger.kernel.org Cc: linux-x25@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17netrom: use linux/uaccess.hFabian Frederick
replace asm/uaccess.h by linux/uaccess.h Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2008-01-28[NET]: Convert init_timer into setup_timerPavel Emelyanov
Many-many code in the kernel initialized the timer->function and timer->data together with calling init_timer(timer). There is already a helper for this. Use it for networking code. The patch is HUGE, but makes the code 130 lines shorter (98 insertions(+), 228 deletions(-)). Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10[NET] NETROM: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-12[NETROM]: Drop lock before calling nr_destroy_socketRalf Baechle
nr_destroy_socket takes the socket lock itself so it should better be called with the socket unlocked. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[TCP]: Move the tcp sock states to net/tcp_states.hArnaldo Carvalho de Melo
Lots of places just needs the states, not even linux/tcp.h, where this enum was, needs it. This speeds up development of the refactorings as less sources are rebuilt when things get moved from net/tcp.h. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!