[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20201018192417.4055228-22-sashal@kernel.org>
Date: Sun, 18 Oct 2020 15:23:43 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Rustam Kovhaev <rkovhaev@...il.com>,
syzbot+aed06913f36eff9b544e@...kaller.appspotmail.com,
Andrew Morton <akpm@...ux-foundation.org>,
Anton Altaparmakov <anton@...era.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Sasha Levin <sashal@...nel.org>,
linux-ntfs-dev@...ts.sourceforge.net
Subject: [PATCH AUTOSEL 4.19 22/56] ntfs: add check for mft record size in superblock
From: Rustam Kovhaev <rkovhaev@...il.com>
[ Upstream commit 4f8c94022f0bc3babd0a124c0a7dcdd7547bd94e ]
Number of bytes allocated for mft record should be equal to the mft record
size stored in ntfs superblock as reported by syzbot, userspace might
trigger out-of-bounds read by dereferencing ctx->attr in ntfs_attr_find()
Reported-by: syzbot+aed06913f36eff9b544e@...kaller.appspotmail.com
Signed-off-by: Rustam Kovhaev <rkovhaev@...il.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Tested-by: syzbot+aed06913f36eff9b544e@...kaller.appspotmail.com
Acked-by: Anton Altaparmakov <anton@...era.com>
Link: https://syzkaller.appspot.com/bug?extid=aed06913f36eff9b544e
Link: https://lkml.kernel.org/r/20200824022804.226242-1-rkovhaev@gmail.com
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
fs/ntfs/inode.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index bd3221cbdd956..0d4b5b9843b62 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -1835,6 +1835,12 @@ int ntfs_read_inode_mount(struct inode *vi)
brelse(bh);
}
+ if (le32_to_cpu(m->bytes_allocated) != vol->mft_record_size) {
+ ntfs_error(sb, "Incorrect mft record size %u in superblock, should be %u.",
+ le32_to_cpu(m->bytes_allocated), vol->mft_record_size);
+ goto err_out;
+ }
+
/* Apply the mst fixups. */
if (post_read_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size)) {
/* FIXME: Try to use the $MFTMirr now. */
--
2.25.1
Powered by blists - more mailing lists