From: Eric Dumazet edumazet@google.com
[ Upstream commit 2d1f274b95c6e4ba6a813b3b8e7a1a38d54a0a08 ]
syzbot found that alloc_sk_msg() could be called from a non sleepable context. sk_psock_verdict_recv() uses rcu_read_lock() protection.
We need the callers to pass a gfp_t argument to avoid issues.
syzbot report was:
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 3613, name: syz-executor414 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 INFO: lockdep is turned off. CPU: 0 PID: 3613 Comm: syz-executor414 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 __might_resched+0x538/0x6a0 kernel/sched/core.c:9877 might_alloc include/linux/sched/mm.h:274 [inline] slab_pre_alloc_hook mm/slab.h:700 [inline] slab_alloc_node mm/slub.c:3162 [inline] slab_alloc mm/slub.c:3256 [inline] kmem_cache_alloc_trace+0x59/0x310 mm/slub.c:3287 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] alloc_sk_msg net/core/skmsg.c:507 [inline] sk_psock_skb_ingress_self+0x5c/0x330 net/core/skmsg.c:600 sk_psock_verdict_apply+0x395/0x440 net/core/skmsg.c:1014 sk_psock_verdict_recv+0x34d/0x560 net/core/skmsg.c:1201 tcp_read_skb+0x4a1/0x790 net/ipv4/tcp.c:1770 tcp_rcv_established+0x129d/0x1a10 net/ipv4/tcp_input.c:5971 tcp_v4_do_rcv+0x479/0xac0 net/ipv4/tcp_ipv4.c:1681 sk_backlog_rcv include/net/sock.h:1109 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2906 release_sock+0x5d/0x1c0 net/core/sock.c:3462 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1483 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] __sys_sendto+0x46d/0x5f0 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2125 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 43312915b5ba ("skmsg: Get rid of unncessary memset()") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: Cong Wang cong.wang@bytedance.com Cc: Daniel Borkmann daniel@iogearbox.net Cc: John Fastabend john.fastabend@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/skmsg.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index ca70525621c7..1efdc47a999b 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -500,11 +500,11 @@ bool sk_msg_is_readable(struct sock *sk) } EXPORT_SYMBOL_GPL(sk_msg_is_readable);
-static struct sk_msg *alloc_sk_msg(void) +static struct sk_msg *alloc_sk_msg(gfp_t gfp) { struct sk_msg *msg;
- msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_KERNEL); + msg = kzalloc(sizeof(*msg), gfp | __GFP_NOWARN); if (unlikely(!msg)) return NULL; sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS); @@ -520,7 +520,7 @@ static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk, if (!sk_rmem_schedule(sk, skb, skb->truesize)) return NULL;
- return alloc_sk_msg(); + return alloc_sk_msg(GFP_KERNEL); }
static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb, @@ -597,7 +597,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb, static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb, u32 off, u32 len) { - struct sk_msg *msg = alloc_sk_msg(); + struct sk_msg *msg = alloc_sk_msg(GFP_ATOMIC); struct sock *sk = psock->sk; int err;