[PATCH 5.14 023/432] ceph: fix dereference of null pointer cf

Greg Kroah-Hartman
2021-09-16T17:19:35Z

From: Colin Ian King <colin.king@canonical.com>

commit 05a444d3f90a3c3e6362e88a1bf13e1a60f8cace upstream.

Currently in the case where kmem_cache_alloc fails the null pointer
cf is dereferenced when assigning cf->is_capsnap = false. Fix this
by adding a null pointer check and return path.

Cc: stable@vger.kernel.org
Addresses-Coverity: ("Dereference null return")
Fixes: b2f9fa1f3bd8 ("ceph: correctly handle releasing an embedded cap flush")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ceph/caps.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1746,6 +1746,9 @@ struct ceph_cap_flush *ceph_alloc_cap_fl
struct ceph_cap_flush *cf;

cf = kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL);
+ if (!cf)
+ return NULL;
+
cf->is_capsnap = false;
return cf;
}