From 17081633e22d83be928a779fd7acd04b247dec90 Mon Sep 17 00:00:00 2001 From: Guvenc Gulce Date: Fri, 25 Jun 2021 17:11:02 +0200 Subject: net/smc: Ensure correct state of the socket in send path When smc_sendmsg() is called before the SMC socket initialization has completed, smc_tx_sendmsg() will access un-initialized fields of the SMC socket which results in a null-pointer dereference. Fix this by checking the socket state first in smc_tx_sendmsg(). Fixes: e0e4b8fa5338 ("net/smc: Add SMC statistics support") Reported-by: syzbot+5dda108b672b54141857@syzkaller.appspotmail.com Reviewed-by: Karsten Graul Signed-off-by: Guvenc Gulce Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/smc_tx.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 075c4f4b41cf..289025cd545a 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -154,6 +154,9 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) goto out_err; } + if (sk->sk_state == SMC_INIT) + return -ENOTCONN; + if (len > conn->sndbuf_desc->len) SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); @@ -164,8 +167,6 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) SMC_STAT_INC(smc, urg_data_cnt); while (msg_data_left(msg)) { - if (sk->sk_state == SMC_INIT) - return -ENOTCONN; if (smc->sk.sk_shutdown & SEND_SHUTDOWN || (smc->sk.sk_err == ECONNABORTED) || conn->killed) -- cgit