[PATCH v1 7/9] ntfs: fix kmap_local leak in write_mft_record_nolock() error paths

[Baolin Liu]

From: Baolin Liu <liubaolin@xxxxxxxxxx>

write_mft_record_nolock() maps the MFT record folio with
kmap_local_folio(), but the pre_write_mst_fixup() and
bio_add_folio() failure paths jump to the error label without
unmapping it. kmap_local mappings are stack-ordered per task, so
leaking one corrupts the nesting for any outer mapping.

Unmap the folio on those error paths too.

Fixes: 115380f9a2f9 ("ntfs: update mft operations")
Signed-off-by: Baolin Liu <liubaolin@xxxxxxxxxx>
---
 fs/ntfs/mft.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
index 984a0827f9ac..69b007e574fc 100644
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -580,7 +580,7 @@ int write_mft_record_nolock(struct ntfs_inode *ni, struct mft_record *m, int syn
 	err = pre_write_mst_fixup((struct ntfs_record *)fixup_m, vol->mft_record_size);
 	if (err) {
 		ntfs_error(vol->sb, "Failed to apply mst fixups!");
-		goto err_out;
+		goto unmap_err_out;
 	}
 
 	folio_size = vol->mft_record_size / ni->mft_lcn_count;
@@ -645,6 +645,8 @@ int write_mft_record_nolock(struct ntfs_inode *ni, struct mft_record *m, int syn
 	return 0;
 put_bio_out:
 	bio_put(bio);
+unmap_err_out:
+	kunmap_local(kaddr);
 err_out:
 	/*
 	 * The caller should mark the base inode as bad so no more I/O
-- 
2.51.0