linux-kernel - Re: [syzbot] KASAN: use-after-free Read in kernfs

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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <Yi91RwY/UDPJ4iky@kroah.com>
Date:   Mon, 14 Mar 2022 18:03:03 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Tejun Heo <tj@...nel.org>
Cc:     syzbot <syzbot+97a16334dbd58916f7fb@...kaller.appspotmail.com>,
        linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] KASAN: use-after-free Read in kernfs_get

On Mon, Mar 14, 2022 at 06:05:32AM -1000, Tejun Heo wrote:
> On Mon, Mar 14, 2022 at 06:49:19AM -0700, syzbot wrote:
> > Hello,
> > 
> > syzbot found the following issue on:
> > 
> > HEAD commit:    09688c0166e7 Linux 5.17-rc8
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=11b42729700000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=6da459dcfde3b8d0
> > dashboard link: https://syzkaller.appspot.com/bug?extid=97a16334dbd58916f7fb
> > compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
> > 
> > Unfortunately, I don't have any reproducer for this issue yet.
> > 
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+97a16334dbd58916f7fb@...kaller.appspotmail.com
> > 
> > usb 1-1: Direct firmware load for ueagle-atm/adi930.fw failed with error -2
> > usb 1-1: Falling back to sysfs fallback for: ueagle-atm/adi930.fw
> > ==================================================================
> > BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline]
> > BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
> > BUG: KASAN: use-after-free in kernfs_get+0x1c/0x90 fs/kernfs/dir.c:496
> > Read of size 4 at addr ffff88801ded39f8 by task kworker/1:2/2510
> 
> Looks like firmware loading and usb hub removal racing? I'm not sure there's
> whole lot we can do from the kernfs side. Greg?

Odd. Let me look at it.  If syzbot is starting to poke at ATM drivers,
wow, lots of issues are going to start falling out... 

thanks,

greg k-h