From: Andrew Ballance <andrewjballance@gmail.com>
To: syzbot+39b2fb0f2638669008ec@syzkaller.appspotmail.com
Cc: almaz.alexandrovich@paragon-software.com,
linux-kernel@vger.kernel.org, ntfs3@lists.linux.dev,
syzkaller-bugs@googlegroups.com, skhan@linuxfoundation.org,
linux-kernel-mentees@lists.linuxfoundation.org,
Andrew Ballance <andrewjballance@gmail.com>
Subject: [PATCH] ntfs3: check if more than chunk-size bytes are written
Date: Wed, 15 May 2024 07:38:33 -0500 [thread overview]
Message-ID: <20240515123946.874688-1-andrewjballance@gmail.com> (raw)
In-Reply-To: <00000000000077d29606186c5e99@google.com>
#syz test
a incorrectly formatted chunk may decompress into
more than LZNT_CHUNK_SIZE bytes and a index out of bounds
will occur in s_max_off.
Signed-off-by: Andrew Ballance <andrewjballance@gmail.com>
---
fs/ntfs3/lznt.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/ntfs3/lznt.c b/fs/ntfs3/lznt.c
index 4aae598d6d88..fdc9b2ebf341 100644
--- a/fs/ntfs3/lznt.c
+++ b/fs/ntfs3/lznt.c
@@ -236,6 +236,9 @@ static inline ssize_t decompress_chunk(u8 *unc, u8 *unc_end, const u8 *cmpr,
/* Do decompression until pointers are inside range. */
while (up < unc_end && cmpr < cmpr_end) {
+ // return err if more than LZNT_CHUNK_SIZE bytes are written
+ if (up - unc > LZNT_CHUNK_SIZE)
+ return -EINVAL;
/* Correct index */
while (unc + s_max_off[index] < up)
index += 1;
--
2.45.0
next parent reply other threads:[~2024-05-15 12:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <00000000000077d29606186c5e99@google.com>
2024-05-15 12:38 ` Andrew Ballance [this message]
2024-05-15 12:59 ` [syzbot] [ntfs3?] UBSAN: array-index-out-of-bounds in decompress_lznt syzbot
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