summaryrefslogtreecommitdiff
path: root/net/sctp/socket.c
diff options
context:
space:
mode:
authorXin Long <lucien.xin@gmail.com>2023-04-02 02:09:57 +0300
committerDavid S. Miller <davem@davemloft.net>2023-04-02 15:44:58 +0300
commit2584024b23552c00d95b50255e47bd18d306d31a (patch)
tree1ab904903553e04db71b7e339bdfbdc4dd1b3c52 /net/sctp/socket.c
parente669ce46740a9815953bb4452a6bc5a7fdc21a50 (diff)
downloadlinux-2584024b23552c00d95b50255e47bd18d306d31a.tar.xz
sctp: check send stream number after wait_for_sndbuf
This patch fixes a corner case where the asoc out stream count may change after wait_for_sndbuf. When the main thread in the client starts a connection, if its out stream count is set to N while the in stream count in the server is set to N - 2, another thread in the client keeps sending the msgs with stream number N - 1, and waits for sndbuf before processing INIT_ACK. However, after processing INIT_ACK, the out stream count in the client is shrunk to N - 2, the same to the in stream count in the server. The crash occurs when the thread waiting for sndbuf is awake and sends the msg in a non-existing stream(N - 1), the call trace is as below: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] Call Trace: <TASK> sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170 sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163 sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868 sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825 sock_sendmsg_nosec net/socket.c:722 [inline] sock_sendmsg+0xde/0x190 net/socket.c:745 The fix is to add an unlikely check for the send stream number after the thread wakes up from the wait_for_sndbuf. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: syzbot+47c24ca20a2fa01f082e@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/socket.c')
-rw-r--r--net/sctp/socket.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index b91616f819de..218e0982c370 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1830,6 +1830,10 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
if (err)
goto err;
+ if (unlikely(sinfo->sinfo_stream >= asoc->stream.outcnt)) {
+ err = -EINVAL;
+ goto err;
+ }
}
if (sctp_state(asoc, CLOSED)) {