Re: panic: kernel diagnostic assertion "timo || _kernel_lock_held()" failed

[Vitaliy Makkoveev]

On Tue, Dec 06, 2022 at 07:56:13PM +0100, Paul de Weerd wrote:
> I was playing with the USB NIC that's in my (USB-C) monitor.  As soon
> as I do traffic over the interface, I get a kernel panic:
> 
> panic: kernel diagnostic assertion "timo || _kernel_lock_held()" failed: file 
> "/usr/src/sys/kern/kern_synch.c", line 127
> 

I missed, in{,6}_addmulti() have no kernel lock around (*if_ioctl)().
But corresponding in{,6}_delmulti() have.

Index: sys/netinet/in.c
===================================================================
RCS file: /cvs/src/sys/netinet/in.c,v
retrieving revision 1.178
diff -u -p -r1.178 in.c
--- sys/netinet/in.c    19 Nov 2022 14:26:40 -0000      1.178
+++ sys/netinet/in.c    6 Dec 2022 19:47:12 -0000
@@ -885,10 +885,13 @@ in_addmulti(struct in_addr *ap, struct i
                 */
                memset(&ifr, 0, sizeof(ifr));
                memcpy(&ifr.ifr_addr, &inm->inm_sin, sizeof(inm->inm_sin));
+               KERNEL_LOCK();
                if ((*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
+                       KERNEL_UNLOCK();
                        free(inm, M_IPMADDR, sizeof(*inm));
                        return (NULL);
                }
+               KERNEL_UNLOCK();
 
                TAILQ_INSERT_HEAD(&ifp->if_maddrlist, &inm->inm_ifma,
                    ifma_list);
Index: sys/netinet6/in6.c
===================================================================
RCS file: /cvs/src/sys/netinet6/in6.c,v
retrieving revision 1.258
diff -u -p -r1.258 in6.c
--- sys/netinet6/in6.c  2 Dec 2022 12:56:51 -0000       1.258
+++ sys/netinet6/in6.c  6 Dec 2022 19:47:12 -0000
@@ -1063,7 +1063,9 @@ in6_addmulti(struct in6_addr *maddr6, st
                 * filter appropriately for the new address.
                 */
                memcpy(&ifr.ifr_addr, &in6m->in6m_sin, sizeof(in6m->in6m_sin));
+               KERNEL_LOCK();
                *errorp = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)&ifr);
+               KERNEL_UNLOCK();
                if (*errorp) {
                        free(in6m, M_IPMADDR, sizeof(*in6m));
                        return (NULL);