diff mbox series

[007/173] ntfs: check for valid standard information attribute

Message ID 20210224200030.F8x-RJnAx%akpm@linux-foundation.org
State New
Headers show
Series None | expand

Commit Message

Andrew Morton Feb. 24, 2021, 8 p.m. UTC 
From: Rustam Kovhaev <rkovhaev@gmail.com>
Subject: ntfs: check for valid standard information attribute

Mounting a corrupted filesystem with NTFS resulted in a kernel crash.

We should check for valid STANDARD_INFORMATION attribute offset and length
before trying to access it

Link: https://lkml.kernel.org/r/20210217155930.1506815-1-rkovhaev@gmail.com
Link: https://syzkaller.appspot.com/bug?extid=c584225dabdea2f71969
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Reported-by: syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com
Tested-by: syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com
Acked-by: Anton Altaparmakov <anton@tuxera.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ntfs/inode.c |    6 ++++++
 1 file changed, 6 insertions(+)
diff mbox series

Patch

--- a/fs/ntfs/inode.c~ntfs-check-for-valid-standard-information-attribute
+++ a/fs/ntfs/inode.c
@@ -629,6 +629,12 @@  static int ntfs_read_locked_inode(struct
 	}
 	a = ctx->attr;
 	/* Get the standard information attribute value. */
+	if ((u8 *)a + le16_to_cpu(a->data.resident.value_offset)
+			+ le32_to_cpu(a->data.resident.value_length) >
+			(u8 *)ctx->mrec + vol->mft_record_size) {
+		ntfs_error(vi->i_sb, "Corrupt standard information attribute in inode.");
+		goto unm_err_out;
+	}
 	si = (STANDARD_INFORMATION*)((u8*)a +
 			le16_to_cpu(a->data.resident.value_offset));