[Linux-NTFS-Dev] [PATCH v2] fs/ntfs: fix BUG_ON of ntfs_read_block()

[<cge...@gm...>]

From: xu xin <xu....@zt...>

As the bug description at
https://lore.kernel.org/lkml/202...@zt.../
attckers can use this bug to crash the system.

So to avoid panic, remove the BUG_ON, and use ntfs_warning to output a
warning to the syslog and return instead until someone really solve
the problem.

Cc: st...@vg...
Reported-by: Zeal Robot <ze...@zt...>
Reported-by: syz...@sy...
Reviewed-by: Songyi Zhang <zha...@zt...>
Reviewed-by: Yang Yang <yan...@zt...>
Reviewed-by: Jiang Xuexin<jia...@zt...>
Reviewed-by: Zhang wenya<zha...@zt...>
Signed-off-by: xu xin <xu....@zt...>
---

Change for v2:
 - Use ntfs_warning instead of WARN().
 - Add the tag Cc: st...@vg....
---
 fs/ntfs/aops.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 5f4fb6ca6f2e..84d68efb4ace 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -183,7 +183,12 @@ static int ntfs_read_block(struct page *page)
 	vol = ni->vol;
 
 	/* $MFT/$DATA must have its complete runlist in memory at all times. */
-	BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni));
+	if (unlikely(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni))) {
+		ntfs_warning(vi->i_sb, "Error because ni->runlist.rl, ni->mft_no, "
+				"and NInoAttr(ni) is null.");
+		unlock_page(page);
+		return -EINVAL;
+	}
 
 	blocksize = vol->sb->s_blocksize;
 	blocksize_bits = vol->sb->s_blocksize_bits;
-- 
2.25.1