Commit 17081633 authored Jun 25, 2021 by Guvenc Gulce Committed by David S. Miller Jun 25, 2021

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: e0e4b8fa ("net/smc: Add SMC statistics support")
Reported-by:  <syzbot+5dda108b672b54141857@syzkaller.appspotmail.com>
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4e3db44a

net/smc/smc_tx.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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)