dm-integrity: fix a memory leak when rechecking the data

[ Upstream commit 55e565c42dce81a4e49c13262d5bc4eb4c2e588a ]

Memory for the "checksums" pointer will leak if the data is rechecked
after checksum failure (because the associated kfree won't happen due
to 'goto skip_io').

Fix this by freeing the checksums memory before recheck, and just use
the "checksum_onstack" memory for storing checksum during recheck.

Fixes: c88f5e553fe3 ("dm-integrity: recheck the integrity tag after a failure")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 1fc901df84eb163c833e364d21e0a48e65c06239..f194ce6bfacb5cb964d76f04f8c975b2b60c2604 100644 (file)
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1848,12 +1848,12 @@ static void integrity_metadata(struct work_struct *w)
                        r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
                                                checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE);
                        if (unlikely(r)) {
+                               if (likely(checksums != checksums_onstack))
+                                       kfree(checksums);
                                if (r > 0) {
-                                       integrity_recheck(dio, checksums);
+                                       integrity_recheck(dio, checksums_onstack);
                                        goto skip_io;
                                }
-                               if (likely(checksums != checksums_onstack))
-                                       kfree(checksums);
                                goto error;
                        }