From: Colin Ian King <colin.king@xxxxxxxxxxxxx> There is a null check on the pointer bh to avoid a null pointer dereference on bh->b_data however later bh is passed to mark_buffer_dirty that can also cause a null pointer dereference on bh. Avoid this potential null pointer dereference by moving the call to mark_buffer_dirty inside the null checked block. Fixes: e8b4274735e4 ("udf: finalize integrity descriptor before writeback") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> --- fs/udf/super.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index a6940d90bedd..b7e9a83d39db 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -2336,13 +2336,13 @@ static int udf_sync_fs(struct super_block *sb, int wait) lvid = (struct logicalVolIntegrityDesc *)bh->b_data; udf_finalize_lvid(lvid); - } - /* - * Blockdevice will be synced later so we don't have to submit - * the buffer for IO - */ - mark_buffer_dirty(bh); + /* + * Blockdevice will be synced later so we don't have + * to submit the buffer for IO + */ + mark_buffer_dirty(bh); + } sbi->s_lvid_dirty = 0; } mutex_unlock(&sbi->s_alloc_mutex); -- 2.20.1