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| author | Hangyu Hua <hbh25y@gmail.com> | 2022-07-29 19:00:27 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:15:13 +0200 |
| commit | 7ba88eacf014d501255106b6326892da59f23683 (patch) | |
| tree | 3d8d048c6dc0c44c660310f25c526ff9393d354f /net | |
| parent | e6dee1fbd36a4c982d4edb73ced1fb03564fa3ed (diff) | |
| download | linux-stable-7ba88eacf014d501255106b6326892da59f23683.tar.gz linux-stable-7ba88eacf014d501255106b6326892da59f23683.tar.bz2 linux-stable-7ba88eacf014d501255106b6326892da59f23683.zip | |
dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock
[ Upstream commit a41b17ff9dacd22f5f118ee53d82da0f3e52d5e3 ]
In the case of sk->dccps_qpolicy == DCCPQ_POLICY_PRIO, dccp_qpolicy_full
will drop a skb when qpolicy is full. And the lock in dccp_sendmsg is
released before sock_alloc_send_skb and then relocked after
sock_alloc_send_skb. The following conditions may lead dccp_qpolicy_push
to add skb to an already full sk_write_queue:
thread1--->lock
thread1--->dccp_qpolicy_full: queue is full. drop a skb
thread1--->unlock
thread2--->lock
thread2--->dccp_qpolicy_full: queue is not full. no need to drop.
thread2--->unlock
thread1--->lock
thread1--->dccp_qpolicy_push: add a skb. queue is full.
thread1--->unlock
thread2--->lock
thread2--->dccp_qpolicy_push: add a skb!
thread2--->unlock
Fix this by moving dccp_qpolicy_full.
Fixes: b1308dc015eb ("[DCCP]: Set TX Queue Length Bounds via Sysctl")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20220729110027.40569-1-hbh25y@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/dccp/proto.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 43733accf58e..dbbcf50aea35 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -769,11 +769,6 @@ int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) lock_sock(sk); - if (dccp_qpolicy_full(sk)) { - rc = -EAGAIN; - goto out_release; - } - timeo = sock_sndtimeo(sk, noblock); /* @@ -792,6 +787,11 @@ int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (skb == NULL) goto out_release; + if (dccp_qpolicy_full(sk)) { + rc = -EAGAIN; + goto out_discard; + } + if (sk->sk_state == DCCP_CLOSED) { rc = -ENOTCONN; goto out_discard; |