lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Tue, 30 Jun 2020 11:34:49 -0700
From:   Costa Sapuntzakis <costa@...estorage.com>
To:     Jan Kara <jack@...e.cz>
Cc:     linux-ext4@...r.kernel.org
Subject: Re: [BUG] invalid superblock checksum possibly due to race

Hello and thank you!

> Yes, probably ext4_superblock_csum_set() should use
>
> lock_buffer(EXT4_SB(sb)->s_sbh)
>
> to synchronize updating of superblock checksum. Will you send a patch?

Yes. I will send a patch.

I noticed lock_buffer can sleep. That would seem to imply to me that
lock_buffer can be held across I/Os.
I worry that this will occasionally significantly slow down this code
path compared to what it used to be.  Are there any things
about the way ext4 uses buffers that makes this less of a concern?

-Costa

Powered by blists - more mailing lists