On 5/7/19 12:37 AM, David Sterba wrote:
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.
There is no goto out_free_ulist inside the while loop; where do you see
that? I did git pull again and checked.
4664 while (!end) {
::
4726 goto out_free;
::
4748 goto out;
::
4759 goto out_free;
::
4761 }
