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: 44ed167da7 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf")
Cc: stable@vger.kernel.org
Signed-off-by: Mikhail Lobanov <m.lobanov@rosalinux.ru>
Link: https://lore.kernel.org/r/20240909133740.84297-1-m.lobanov@rosalinux.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Mikhail Lobanov 2024-09-09 09:37:36 -04:00 committed by Jens Axboe
parent acc8c0a988
commit a5e61b50c9

View File

@ -876,7 +876,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns)
ns.disk == D_OUTDATED) ns.disk == D_OUTDATED)
rv = SS_CONNECTED_OUTDATES; 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)) (nc->verify_alg[0] == 0))
rv = SS_NO_VERIFY_ALG; rv = SS_NO_VERIFY_ALG;