From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 30 Jan 2017 09:55:04 +0000 (+0100)
Subject: smc: some potential use after free bugs
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cdaf25dfc058ee6f7a7b2e2353de00fa288c0cd4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

smc: some potential use after free bugs

Say we got really unlucky and these failed on the last iteration, then
it could lead to a use after free bug.

Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 8b1d34378829..0eac633fb354 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -532,6 +532,7 @@ int smc_sndbuf_create(struct smc_sock *smc)
 						__GFP_NORETRY);
 		if (!sndbuf_desc->cpu_addr) {
 			kfree(sndbuf_desc);
+			sndbuf_desc = NULL;
 			/* if send buffer allocation has failed,
 			 * try a smaller one
 			 */
@@ -543,6 +544,7 @@ int smc_sndbuf_create(struct smc_sock *smc)
 		if (rc) {
 			kfree(sndbuf_desc->cpu_addr);
 			kfree(sndbuf_desc);
+			sndbuf_desc = NULL;
 			continue; /* if mapping failed, try smaller one */
 		}
 		sndbuf_desc->used = 1;
@@ -596,6 +598,7 @@ int smc_rmb_create(struct smc_sock *smc)
 					     __GFP_NORETRY);
 		if (!rmb_desc->cpu_addr) {
 			kfree(rmb_desc);
+			rmb_desc = NULL;
 			/* if RMB allocation has failed,
 			 * try a smaller one
 			 */
@@ -607,6 +610,7 @@ int smc_rmb_create(struct smc_sock *smc)
 		if (rc) {
 			kfree(rmb_desc->cpu_addr);
 			kfree(rmb_desc);
+			rmb_desc = NULL;
 			continue; /* if mapping failed, try smaller one */
 		}
 		rc = smc_ib_get_memory_region(lgr->lnk[SMC_SINGLE_LINK].roce_pd,
@@ -619,6 +623,7 @@ int smc_rmb_create(struct smc_sock *smc)
 					 DMA_FROM_DEVICE);
 			kfree(rmb_desc->cpu_addr);
 			kfree(rmb_desc);
+			rmb_desc = NULL;
 			continue;
 		}
 		rmb_desc->used = 1;