On 08/01/2016 06:55 AM, Theodore Ts'o wrote:
On Sat, Jul 30, 2016 at 03:04:43PM +0200, Vegard Nossum wrote:
Hi,
It's been two weeks since I posted the first list of bugs found using
AFL: https://www.spinics.net/lists/linux-ext4/msg53022.html
With a bunch of ext4 patches going into 4.8 we're down from 15 to 6
with current linus/master...
Does this patch bring things down further? I expect it should at the
very list address
6. WARNING: CPU: 0 PID: 58 at fs/ext4/ext4.h:2748
ext4_block_bitmap_csum_set+0x358/0x600
http://139.162.151.198/f/ext4/9628c19aff0bbaaae4149a03486305c7f6cd7523
... and possibly others.
I applied the patch, but I didn't see any of the bugs go away,
unfortunately.
IIRC there were still bugs in ext4_init_block_bitmap() where the
ext4_set_bit() calls for the block bitmap + inode bitmap + inode table
were writing beyond the end of bh->b_data. I think tmp < start or
something and then the ext4_set_bit() calls actually end up writing
into the superblock itself, causing either ext4_inode_table() or
sbi->s_itb_per_group to start returning bogus values and further corrupt
things. I'll have another look, maybe add some printks.
If there are any remaining of these bugs where the superblock is
sufficiently corrupt that dumpe2fs refuses to print anything, could
you print a hex dump of the superblock (located at offset 1024) so we
could see what is going on?
I've added the hex dumps and updated the pages.
Vegard
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
