From: Mikhail Lobanov Date: Mon, 9 Sep 2024 13:37:36 +0000 (-0400) Subject: drbd: Add NULL check for net_conf to prevent dereference in state validation X-Git-Tag: v6.12-rc1~204^2~16 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a5e61b50c9f44c5edb6e134ede6fee8806ffafa9;p=thirdparty%2Flinux.git drbd: Add NULL check for net_conf to prevent dereference in state validation If the net_conf pointer is NULL and the code attempts to access its fields without a check, it will lead to a null pointer dereference. Add a NULL check before dereferencing the pointer. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 44ed167da748 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf") Cc: stable@vger.kernel.org Signed-off-by: Mikhail Lobanov Link: https://lore.kernel.org/r/20240909133740.84297-1-m.lobanov@rosalinux.ru Signed-off-by: Jens Axboe --- diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c index e858e7e0383f2..c2b6c4d9729db 100644 --- a/drivers/block/drbd/drbd_state.c +++ b/drivers/block/drbd/drbd_state.c @@ -876,7 +876,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns) ns.disk == D_OUTDATED) rv = SS_CONNECTED_OUTDATES; - else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && + else if (nc && (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && (nc->verify_alg[0] == 0)) rv = SS_NO_VERIFY_ALG;