On Tue, Jan 05, 2021 at 12:21:26PM -0800, trix@xxxxxxxxxx wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
> fs/cifs/dfs_cache.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> 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);
> }
>
> /**
> --
> 2.27.0
>
