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Subject[PATCH] ntfs: change check order in ntfs_attr_find
Date
syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Looks like it is improper check order that causes this bug.

Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
---
fs/ntfs/attrib.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 52615e6090e1..6480cd2d371d 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -594,10 +594,11 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) {
u8 *mrec_end = (u8 *)ctx->mrec +
le32_to_cpu(ctx->mrec->bytes_allocated);
+ if ((u8*)a < (u8*)ctx->mrec || (u8*)a > mrec_end)
+ break;
u8 *name_end = (u8 *)a + le16_to_cpu(a->name_offset) +
a->name_length * sizeof(ntfschar);
- if ((u8*)a < (u8*)ctx->mrec || (u8*)a > mrec_end ||
- name_end > mrec_end)
+ if (name_end > mrec_end)
break;
ctx->attr = a;
if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
--
2.25.1
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