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| author | Eric Dumazet <edumazet@google.com> | 2021-06-30 09:42:44 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-01 13:23:19 -0700 |
| commit | 18a419bad63b7f68a1979e28459782518e7b6bbe (patch) | |
| tree | e6c3fcc5fb6a03acdb1c70a889670234f3c8ad98 | |
| parent | 71158bb1f2d2da61385c58fc1114e1a1c19984ba (diff) | |
| download | lwn-18a419bad63b7f68a1979e28459782518e7b6bbe.tar.gz lwn-18a419bad63b7f68a1979e28459782518e7b6bbe.zip | |
udp: annotate data races around unix_sk(sk)->gso_size
Accesses to unix_sk(sk)->gso_size are lockless.
Add READ_ONCE()/WRITE_ONCE() around them.
BUG: KCSAN: data-race in udp_lib_setsockopt / udpv6_sendmsg
write to 0xffff88812d78f47c of 2 bytes by task 10849 on cpu 1:
udp_lib_setsockopt+0x3b3/0x710 net/ipv4/udp.c:2696
udpv6_setsockopt+0x63/0x90 net/ipv6/udp.c:1630
sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3265
__sys_setsockopt+0x18f/0x200 net/socket.c:2104
__do_sys_setsockopt net/socket.c:2115 [inline]
__se_sys_setsockopt net/socket.c:2112 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88812d78f47c of 2 bytes by task 10852 on cpu 0:
udpv6_sendmsg+0x161/0x16b0 net/ipv6/udp.c:1299
inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
sock_sendmsg_nosec net/socket.c:654 [inline]
sock_sendmsg net/socket.c:674 [inline]
____sys_sendmsg+0x360/0x4d0 net/socket.c:2337
___sys_sendmsg net/socket.c:2391 [inline]
__sys_sendmmsg+0x315/0x4b0 net/socket.c:2477
__do_sys_sendmmsg net/socket.c:2506 [inline]
__se_sys_sendmmsg net/socket.c:2503 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2503
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x0000 -> 0x0005
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10852 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/udp.c | 6 | ||||
| -rw-r--r-- | net/ipv6/udp.c | 2 |
2 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 62682807b4b2..62cd4cd52e84 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1102,7 +1102,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) } ipcm_init_sk(&ipc, inet); - ipc.gso_size = up->gso_size; + ipc.gso_size = READ_ONCE(up->gso_size); if (msg->msg_controllen) { err = udp_cmsg_send(sk, msg, &ipc.gso_size); @@ -2695,7 +2695,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case UDP_SEGMENT: if (val < 0 || val > USHRT_MAX) return -EINVAL; - up->gso_size = val; + WRITE_ONCE(up->gso_size, val); break; case UDP_GRO: @@ -2790,7 +2790,7 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, break; case UDP_SEGMENT: - val = up->gso_size; + val = READ_ONCE(up->gso_size); break; case UDP_GRO: diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 368972dbd919..0cc7ba531b34 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1296,7 +1296,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); ipcm6_init(&ipc6); - ipc6.gso_size = up->gso_size; + ipc6.gso_size = READ_ONCE(up->gso_size); ipc6.sockc.tsflags = sk->sk_tsflags; ipc6.sockc.mark = sk->sk_mark; |