NACK: [SRU][F/J/M][PATCH 0/2] CVE-2024-26624

[Manuel Diewald]

On Tue, Mar 26, 2024 at 08:18:33PM -0400, Yuxuan Luo wrote:
> [Impact]
> A potential deadlock is found in the AF_UNIX subsystem, the scenario is
> shown below:
> 
>       CPU0                    CPU1
>       ----                    ----
>  lock(&u->lock/1);
>                               lock(rlock-AF_UNIX);
>                               lock(&u->lock/1);
>  lock(rlock-AF_UNIX);
> 
> *** DEADLOCK ***
> Such deadlock could lead to serious denial of service and system crash.
> 
> [Backport]
> The fix is a clean cherry pick.
> 
> However, the modified function has been copied to our own trees
> (security/apparmor/af_unix.c), therefore, a sauce patch is needed to
> synchronize the change.
> 
> [Test]
> Compile and boot tested.
> 
> [Where things could go wrong]
> The fix touches af_unix.c which means most of the use case are affected.
> However, what this fix does is to add "an identifier" to the locks to
> avoid potential deadlock without touching working logic; plus, this fix
> has been backported to multiple stable trees, expect very low regression
> potential. If such happens, it is probably a denial of service.
> 
> Eric Dumazet (1):
>   af_unix: fix lockdep positive in sk_diag_dump_icons()
> 
> Yuxuan Luo (1):
>   UBUNTU: SAUCE: af_unix: fix lockdep positive in sk_diag_dump_icons()
> 
>  include/net/af_unix.h       | 20 ++++++++++++++------
>  net/unix/af_unix.c          | 14 ++++++--------
>  net/unix/diag.c             |  2 +-
>  security/apparmor/af_unix.c | 12 +++++-------
>  4 files changed, 26 insertions(+), 22 deletions(-)
> 
> -- 
> 2.34.1
> 
> 
> -- 
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team

This is part of upstream stable updates that have been applied to focal
and jammy already:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2059014
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2058948

I am currently preparing a mantic patchset that also carries this fix
which will be submitted to the mailing list shortly.

-- 
 Manuel