[dpdk-dev] [PATCH v2] examples/vhost_blk: fix the TOCTOU

Jin Yu jin.yu at intel.com
Wed Feb 12 13:54:46 CET 2020


Fix the time of check time of use warning in example code.
Ignore the errno of unlink failure. There are two situations.
The first one is that file doesn't exist the unlink fails and
it's ok to ignore. The second one is that unlink fails to remove
file but the next bind() would fail too.

Coverity issue: 350589 158663
Fixes: c19beb3f38cd ("examples/vhost_blk: introduce vhost storage sample")
Cc: stable at dpdk.org

Signed-off-by: Jin Yu <jin.yu at intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
V2 - complement the commit message.
---
 examples/vhost_blk/vhost_blk.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/examples/vhost_blk/vhost_blk.c b/examples/vhost_blk/vhost_blk.c
index e1036bf3a..74c82a900 100644
--- a/examples/vhost_blk/vhost_blk.c
+++ b/examples/vhost_blk/vhost_blk.c
@@ -994,11 +994,7 @@ vhost_blk_ctrlr_construct(const char *ctrlr_name)
 	}
 	snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, ctrlr_name);
 
-	if (access(dev_pathname, F_OK) != -1) {
-		if (unlink(dev_pathname) != 0)
-			rte_exit(EXIT_FAILURE, "Cannot remove %s.\n",
-				 dev_pathname);
-	}
+	unlink(dev_pathname);
 
 	if (rte_vhost_driver_register(dev_pathname, 0) != 0) {
 		fprintf(stderr, "socket %s already exists\n", dev_pathname);
@@ -1041,8 +1037,7 @@ signal_handler(__rte_unused int signum)
 {
 	struct vhost_blk_ctrlr *ctrlr;
 
-	if (access(dev_pathname, F_OK) == 0)
-		unlink(dev_pathname);
+	unlink(dev_pathname);
 
 	if (g_should_stop != -1) {
 		g_should_stop = 1;
-- 
2.17.2



More information about the dev mailing list