diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-01-12 10:44:27 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-01-13 15:46:20 +0000 |
| commit | 482521d8e0c6520429478aa6866cd44128b33d5d (patch) | |
| tree | f0267ae639ebbb37a9cd6469120d58aa69867fc3 /net/ipv4/udp.c | |
| parent | 08300adac3b8dab9e2fd3be0155c7d3093c755f4 (diff) | |
udp: annotate data-races around up->pending
up->pending can be read without holding the socket lock,
as pointed out by syzbot [1]
Add READ_ONCE() in lockless contexts, and WRITE_ONCE()
on write side.
[1]
BUG: KCSAN: data-race in udpv6_sendmsg / udpv6_sendmsg
write to 0xffff88814e5eadf0 of 4 bytes by task 15547 on cpu 1:
udpv6_sendmsg+0x1405/0x1530 net/ipv6/udp.c:1596
inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:657
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x257/0x310 net/socket.c:2192
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0x78/0x90 net/socket.c:2200
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
read to 0xffff88814e5eadf0 of 4 bytes by task 15551 on cpu 0:
udpv6_sendmsg+0x22c/0x1530 net/ipv6/udp.c:1373
inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:657
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x37c/0x4d0 net/socket.c:2586
___sys_sendmsg net/socket.c:2640 [inline]
__sys_sendmmsg+0x269/0x500 net/socket.c:2726
__do_sys_sendmmsg net/socket.c:2755 [inline]
__se_sys_sendmmsg net/socket.c:2752 [inline]
__x64_sys_sendmmsg+0x57/0x60 net/socket.c:2752
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
value changed: 0x00000000 -> 0x0000000a
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15551 Comm: syz-executor.1 Tainted: G W 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+8d482d0e407f665d9d10@syzkaller.appspotmail.com
Link: https://lore.kernel.org/netdev/0000000000009e46c3060ebcdffd@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 89e5a806b82e..5f742d0b9e07 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -805,7 +805,7 @@ void udp_flush_pending_frames(struct sock *sk) if (up->pending) { up->len = 0; - up->pending = 0; + WRITE_ONCE(up->pending, 0); ip_flush_pending_frames(sk); } } @@ -993,7 +993,7 @@ int udp_push_pending_frames(struct sock *sk) out: up->len = 0; - up->pending = 0; + WRITE_ONCE(up->pending, 0); return err; } EXPORT_SYMBOL(udp_push_pending_frames); @@ -1070,7 +1070,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; fl4 = &inet->cork.fl.u.ip4; - if (up->pending) { + if (READ_ONCE(up->pending)) { /* * There are pending frames. * The socket lock must be held while it's corked. @@ -1269,7 +1269,7 @@ back_from_confirm: fl4->saddr = saddr; fl4->fl4_dport = dport; fl4->fl4_sport = inet->inet_sport; - up->pending = AF_INET; + WRITE_ONCE(up->pending, AF_INET); do_append_data: up->len += ulen; @@ -1281,7 +1281,7 @@ do_append_data: else if (!corkreq) err = udp_push_pending_frames(sk); else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) - up->pending = 0; + WRITE_ONCE(up->pending, 0); release_sock(sk); out: @@ -1319,7 +1319,7 @@ void udp_splice_eof(struct socket *sock) struct sock *sk = sock->sk; struct udp_sock *up = udp_sk(sk); - if (!up->pending || udp_test_bit(CORK, sk)) + if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk)) return; lock_sock(sk); |