ntfs: reinit search context before volume information lookup

On mount the volume inode is searched for $VOLUME_NAME and then, reusing
the same search context, for $VOLUME_INFORMATION. The $VOLUME_NAME lookup
is optional and its result is otherwise ignored.

Once lookup-time validation can reject a corrupt $VOLUME_NAME with -EIO,
the search context is left in an undefined state: ntfs_attr_find()
documents that on an actual error @ctx->attr is undefined. Continuing the
$VOLUME_INFORMATION search from that context is not contractually valid.

Reinitialize the search context before the $VOLUME_INFORMATION lookup so
it always starts from a well-defined state regardless of the
$VOLUME_NAME lookup outcome.

Cc: stable@vger.kernel.org # v7.1
Signed-off-by: DaeMyung Kang <charsyam@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 081a2958386824b778714dabed448b1124a47a1a..ca882e946a22d053c4839a80444a7859a5541c8c 100644 (file)
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -1461,6 +1461,7 @@ iput_volume_failed:
                        vol->volume_label = NULL;
        }
 
+       ntfs_attr_reinit_search_ctx(ctx);
        if (ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
                        ctx) || ctx->attr->non_resident || ctx->attr->flags) {
                ntfs_attr_put_search_ctx(ctx);