CVE-2025-21669: vsock/virtio: discard packets if the transport changes

CKI Backport Botrequested to merge
redhat/red-hat-ci-tools/kernel/bot-branches/centos-stream/src/kernel/centos-stream-9:backport-RHEL-77228-centos-stream-9-main into main

JIRA: https://issues.redhat.com/browse/RHEL-77228
CVE: CVE-2025-21669

vsock/virtio: discard packets if the transport changes

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.

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/
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Hyunwoo Kim <v4bel@theori.io>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

(cherry picked from commit 2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1)

Signed-off-by: CKI Backport Bot cki-ci-bot+cki-gitlab-backport-bot@redhat.com

Created 2025-01-31 18:41 UTC by backporter - KWF FAQ - Slack #team-kernel-workflow - Source - Documentation - Report an issue

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