diff options
| author | Samuel Page <sam@bynar.io> | 2026-04-08 17:30:13 +0300 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2026-04-09 19:51:42 +0300 |
| commit | a535a9217ca3f2fccedaafb2fddb4c48f27d36dc (patch) | |
| tree | db54e3f74d16e5de83f164fbc7fdff7b2d47ae87 | |
| parent | fed4626501c871890da287bec62a96e52da1af89 (diff) | |
| download | linux-a535a9217ca3f2fccedaafb2fddb4c48f27d36dc.tar.xz | |
can: raw: fix ro->uniq use-after-free in raw_rcv()
raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.
Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.
Fixes: 514ac99c64b2 ("can: fix multiple delivery of a single CAN frame for overlapping CAN filters")
Cc: stable@vger.kernel.org # v4.1+
Assisted-by: Bynario AI
Signed-off-by: Samuel Page <sam@bynar.io>
Link: https://patch.msgid.link/26ec626d-cae7-4418-9782-7198864d070c@bynar.io
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
[mkl: applied manually]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | net/can/raw.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/net/can/raw.c b/net/can/raw.c index eee244ffc31e..58a96e933deb 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -361,6 +361,14 @@ static int raw_notifier(struct notifier_block *nb, unsigned long msg, return NOTIFY_DONE; } +static void raw_sock_destruct(struct sock *sk) +{ + struct raw_sock *ro = raw_sk(sk); + + free_percpu(ro->uniq); + can_sock_destruct(sk); +} + static int raw_init(struct sock *sk) { struct raw_sock *ro = raw_sk(sk); @@ -387,6 +395,8 @@ static int raw_init(struct sock *sk) if (unlikely(!ro->uniq)) return -ENOMEM; + sk->sk_destruct = raw_sock_destruct; + /* set notifier */ spin_lock(&raw_notifier_lock); list_add_tail(&ro->notifier, &raw_notifier_list); @@ -436,7 +446,6 @@ static int raw_release(struct socket *sock) ro->bound = 0; ro->dev = NULL; ro->count = 0; - free_percpu(ro->uniq); sock_orphan(sk); sock->sk = NULL; |