From d7d1f986ebb284b1db8dafca7d1bdb6dd2445cf6 Mon Sep 17 00:00:00 2001 From: Guangguan Wang Date: Wed, 11 Dec 2024 17:21:21 +0800 Subject: [PATCH] net/smc: check return value of sock_recvmsg when draining clc data [ Upstream commit c5b8ee5022a19464783058dc6042e8eefa34e8cd ] When receiving clc msg, the field length in smc_clc_msg_hdr indicates the length of msg should be received from network and the value should not be fully trusted as it is from the network. Once the value of length exceeds the value of buflen in function smc_clc_wait_msg it may run into deadloop when trying to drain the remaining data exceeding buflen. This patch checks the return value of sock_recvmsg when draining data in case of deadloop in draining. Fixes: fb4f79264c0f ("net/smc: tolerate future SMCD versions") Signed-off-by: Guangguan Wang Reviewed-by: Wen Gu Reviewed-by: D. Wythe Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_clc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index f734fdd90c81..a48fdc83fe6b 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -753,6 +753,11 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen, SMC_CLC_RECV_BUF_LEN : datlen; iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen); len = sock_recvmsg(smc->clcsock, &msg, krflags); + if (len < recvlen) { + smc->sk.sk_err = EPROTO; + reason_code = -EPROTO; + goto out; + } datlen -= len; } if (clcm->type == SMC_CLC_DECLINE) {