5.10-stable review patch. If anyone has any objections, please let me know.
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From: Guangguan Wang guangguan.wang@linux.alibaba.com
[ 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 guangguan.wang@linux.alibaba.com Reviewed-by: Wen Gu guwen@linux.alibaba.com Reviewed-by: D. Wythe alibuda@linux.alibaba.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 32cbdc321aec..2aa69e29fa1d 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -427,6 +427,11 @@ 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, READ, &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) {