[PATCH 0/2] tun/tap: set sk_uid from current_fsuid()

[Laszlo Ersek <lersek@redhat.com>]

The original patches fixing CVE-2023-1076 are incorrect in my opinion.
This small series fixes them up; see the individual commit messages for
explanation.

I have a very elaborate test procedure demonstrating the problem for
both tun and tap; it involves libvirt, qemu, and "crash". I can share
that procedure if necessary, but it's indeed quite long (I wrote it
originally for our QE team).

The patches in this series are supposed to "re-fix" CVE-2023-1076; given
that said CVE is classified as Low Impact (CVSSv3=5.5), I'm posting this
publicly, and not suggesting any embargo. Red Hat Product Security may
assign a new CVE number later.

I've tested the patches on top of v6.5-rc4, with "crash" built at commit
c74f375e0ef7.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pietro Borrello <borrello@diag.uniroma1.it>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org

Laszlo Ersek (2):
  net: tun_chr_open(): set sk_uid from current_fsuid()
  net: tap_open(): set sk_uid from current_fsuid()

 drivers/net/tap.c | 2 +-
 drivers/net/tun.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)


base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4