On Tue, Jul 02, 2019 at 03:10:28PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently if the allocation of roots or tmp_ulist fails the error handling
> does not free up the allocation of path causing a memory leak. Fix this by
> freeing path with a call to btrfs_free_path before taking the error return
> path.
>
> Addresses-Coverity: ("Resource leak")
Does this have an id, that coverity uses?
> Fixes: 5911c8fe05c5 ("btrfs: fiemap: preallocate ulists for btrfs_check_shared")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> fs/btrfs/extent_io.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 1eb671c16ff1..d7f37a33d597 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -4600,6 +4600,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> tmp_ulist = ulist_alloc(GFP_KERNEL);
> if (!roots || !tmp_ulist) {
> ret = -ENOMEM;
> + btrfs_free_path(path);
This fixes only one leak, therere are more that I spotted while
reviewing this patch. The gotos from the while-loop jump to
out_free_list but that leave the path behind.
That's why the exit block is a better place for the cleanups. This
requires proper nesting of the cleanup calls, that's slightly
inconvenient in this case. The free_path is before call to
unlock_extent_cached so when the ordre is switched and free_path moved
to out_free_ulist, then all the leaks are addressed in one go.
Bummer that the leaks escaped sight of original patch author (me), 2
reviewers and now 1 fix reviewer.
