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authorEric Dumazet <edumazet@google.com>2021-06-30 09:42:44 -0700
committerDavid S. Miller <davem@davemloft.net>2021-07-01 13:23:19 -0700
commit18a419bad63b7f68a1979e28459782518e7b6bbe (patch)
treee6c3fcc5fb6a03acdb1c70a889670234f3c8ad98 /net/ipv4/udp.c
parent71158bb1f2d2da61385c58fc1114e1a1c19984ba (diff)
downloadlinux-next-18a419bad63b7f68a1979e28459782518e7b6bbe.tar.gz
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>
Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r--net/ipv4/udp.c6
1 files changed, 3 insertions, 3 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: