tree d7ba14882e12ad88d22b45524ff2f7902e21e220
parent 6f1a632575f4041290b7c92f0816f7466254f781
author Stefano Garzarella <sgarzare@redhat.com> 1736498107 +0100
committer Arnav Kansal <rnv@google.com> 1738971465 -0800

vsock/virtio: discard packets if the transport changes

commit 2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1 upstream.

If the socket has been de-assigned or assigned to another transport,
we must discard any packets received because they are not expected
and would cause issues when we access vsk->transport.

A possible scenario is described by Hyunwoo Kim in the attached link,
where after a first connect() interrupted by a signal, and a second
connect() failed, we can find `vsk->transport` at NULL, leading to a
NULL pointer dereference.

BUG=b/394549211
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2025-21669 in the Linux kernel.

cos-patch: security-moderate
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Cc: stable@vger.kernel.org
Reported-by: Hyunwoo Kim <v4bel@theori.io>
Reported-by: Wongi Lee <qwerty@theori.io>
Closes: https://lore.kernel.org/netdev/Z2LvdTTQR7dBmPb5@v4bel-B760M-AORUS-ELITE-AX/
Change-Id: I76879fc6c31ee9555a899eee5dd8c8b6de210f95
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Hyunwoo Kim <v4bel@theori.io>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[SG: fixed context conflict since this tree is missing commit 71dc9ec9ac7d
 ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")]
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kernel CVE Triage Automation <cloud-image-kernel-cve-triage-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/92302
Reviewed-by: Kevin Berry <kpberry@google.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>