The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 77b6ec01c29aade01701aa30bf1469acc7f2be76 Mon Sep 17 00:00:00 2001
From: Tom Rix trix@redhat.com Date: Tue, 5 Jan 2021 12:21:26 -0800 Subject: [PATCH] cifs: check pointer before freeing
clang static analysis reports this problem
dfs_cache.c:591:2: warning: Argument to kfree() is a constant address (18446744073709551614), which is not memory allocated by malloc() kfree(vi); ^~~~~~~~~
In dfs_cache_del_vol() the volume info pointer 'vi' being freed is the return of a call to find_vol(). The large constant address is find_vol() returning an error.
Add an error check to dfs_cache_del_vol() similar to the one done in dfs_cache_update_vol().
Fixes: 54be1f6c1c37 ("cifs: Add DFS cache routines") Signed-off-by: Tom Rix trix@redhat.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com CC: stable@vger.kernel.org # v5.0+ Signed-off-by: Steve French stfrench@microsoft.com
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c index 6ad6ba5f6ebe..0fdb0de7ff86 100644 --- a/fs/cifs/dfs_cache.c +++ b/fs/cifs/dfs_cache.c @@ -1260,7 +1260,8 @@ void dfs_cache_del_vol(const char *fullpath) vi = find_vol(fullpath); spin_unlock(&vol_list_lock);
- kref_put(&vi->refcnt, vol_release); + if (!IS_ERR(vi)) + kref_put(&vi->refcnt, vol_release); }
/**