Commit 4dfe6bd9 authored by Rustam Kovhaev's avatar Rustam Kovhaev Committed by Linus Torvalds
Browse files

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: default avatarRustam Kovhaev <rkovhaev@gmail.com>
Reported-by: default avatar <syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com>
Tested-by: default avatar <syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com>
Acked-by: default avatarAnton Altaparmakov <anton@tuxera.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6bbf2901

fs/ntfs/inode.c

+6 −0
Original line number Diff line number Diff line
@@ -629,6 +629,12 @@ static int ntfs_read_locked_inode(struct inode *vi) 
	}

	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));