git: f923f4739628 - stable/15 - if_vxlan(4): Fix panic by validating unused drvspec values

The branch stable/15 has been updated by pouria:

URL: https://cgit.FreeBSD.org/src/commit/?id=f923f4739628fc5c80907dad8b69ae9b38269cd0

commit f923f4739628fc5c80907dad8b69ae9b38269cd0
Author:     Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
AuthorDate: 2026-07-30 13:41:51 +0000
Commit:     Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
CommitDate: 2026-08-02 13:19:47 +0000

    if_vxlan(4): Fix panic by validating unused drvspec values
    
    Add validation for unused parameter values in the gap between
    VXLAN_PARAM_WITH_LOCAL_ADDR4 and VXLAN_PARAM_WITH_LOCAL_ADDR6 to prevent
    panics.
    
    PR:             297151
    Reported by:    Robert Morris <rtm@lcs.mit.edu>
    Reviewed by:    markj
    MFC after:      3 days
    Differential Revision: https://reviews.freebsd.org/D58552
    
    (cherry picked from commit c4d7745cd90fc99af3cbccfda7e11798ea7d187b)
---
 sys/net/if_vxlan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/net/if_vxlan.c b/sys/net/if_vxlan.c
index fc3d3752e0ae..a9c324724cdc 100644
--- a/sys/net/if_vxlan.c
+++ b/sys/net/if_vxlan.c
@@ -2309,7 +2309,8 @@ vxlan_ioctl_drvspec(struct vxlan_softc *sc, struct ifdrv *ifd, int get)
 	} args;
 	int out, error;
 
-	if (ifd->ifd_cmd >= vxlan_control_table_size)
+	if (ifd->ifd_cmd >= vxlan_control_table_size ||
+	    vxlan_control_table[ifd->ifd_cmd].vxlc_func == NULL)
 		return (EINVAL);
 
 	bzero(&args, sizeof(args));