[PATCH 6.6 010/102] cifs: fix use after free for iface while disabling secondary channels

Greg Kroah-Hartman
2024-05-23T13:22:41Z

From: Ritvik Budhiraja <rbudhiraja@microsoft.com>

[ Upstream commit a15ccef82d3de9a37dc25898c60a394209368dc8 ]

We were deferencing iface after it has been released. Fix is to
release after all dereference instances have been encountered.

Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202311110815.UJaeU3Tt-lkp@intel.com/
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/sess.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c
index 09bb30610a901..f3d25395d0d3c 100644
--- a/fs/smb/client/sess.c
+++ b/fs/smb/client/sess.c
@@ -337,10 +337,10 @@ cifs_disable_secondary_channels(struct cifs_ses *ses)

if (iface) {
spin_lock(&ses->iface_lock);
- kref_put(&iface->refcount, release_iface);
iface->num_channels--;
if (iface->weight_fulfilled)
iface->weight_fulfilled--;
+ kref_put(&iface->refcount, release_iface);
spin_unlock(&ses->iface_lock);
}

--
2.43.0