[PATCH 6.6 05/16] fs/ntfs3: Validate ff offset

Greg Kroah-Hartman
2024-07-25T14:45:30Z

From: lei lu <llfamsec@gmail.com>

commit 50c47879650b4c97836a0086632b3a2e300b0f06 upstream.

This adds sanity checks for ff offset. There is a check
on rt->first_free at first, but walking through by ff
without any check. If the second ff is a large offset.
We may encounter an out-of-bound read.

Signed-off-by: lei lu <llfamsec@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ntfs3/fslog.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/fs/ntfs3/fslog.c
+++ b/fs/ntfs3/fslog.c
@@ -724,7 +724,8 @@ static bool check_rstbl(const struct RES

if (!rsize || rsize > bytes ||
rsize + sizeof(struct RESTART_TABLE) > bytes || bytes < ts ||
- le16_to_cpu(rt->total) > ne || ff > ts || lf > ts ||
+ le16_to_cpu(rt->total) > ne ||
+ ff > ts - sizeof(__le32) || lf > ts - sizeof(__le32) ||
(ff && ff < sizeof(struct RESTART_TABLE)) ||
(lf && lf < sizeof(struct RESTART_TABLE))) {
return false;
@@ -754,6 +755,9 @@ static bool check_rstbl(const struct RES
return false;

off = le32_to_cpu(*(__le32 *)Add2Ptr(rt, off));
+
+ if (off > ts - sizeof(__le32))
+ return false;
}

return true;