CVE-2025-21877

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usbnet: gl620a: fix endpoint checking in genelink_bind()<br /> <br /> Syzbot reports [1] a warning in usb_submit_urb() triggered by<br /> inconsistencies between expected and actually present endpoints<br /> in gl620a driver. Since genelink_bind() does not properly<br /> verify whether specified eps are in fact provided by the device,<br /> in this case, an artificially manufactured one, one may get a<br /> mismatch.<br /> <br /> Fix the issue by resorting to a usbnet utility function<br /> usbnet_get_endpoints(), usually reserved for this very problem.<br /> Check for endpoints and return early before proceeding further if<br /> any are missing.<br /> <br /> [1] Syzbot report:<br /> usb 5-1: Manufacturer: syz<br /> usb 5-1: SerialNumber: syz<br /> usb 5-1: config 0 descriptor??<br /> gl620a 5-1:0.23 usb0: register &amp;#39;gl620a&amp;#39; at usb-dummy_hcd.0-1, ...<br /> ------------[ cut here ]------------<br /> usb 5-1: BOGUS urb xfer, pipe 3 != type 1<br /> WARNING: CPU: 2 PID: 1841 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503<br /> Modules linked in:<br /> CPU: 2 UID: 0 PID: 1841 Comm: kworker/2:2 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014<br /> Workqueue: mld mld_ifc_work<br /> RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503<br /> ...<br /> Call Trace:<br /> <br /> usbnet_start_xmit+0x6be/0x2780 drivers/net/usb/usbnet.c:1467<br /> __netdev_start_xmit include/linux/netdevice.h:5002 [inline]<br /> netdev_start_xmit include/linux/netdevice.h:5011 [inline]<br /> xmit_one net/core/dev.c:3590 [inline]<br /> dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3606<br /> sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343<br /> __dev_xmit_skb net/core/dev.c:3827 [inline]<br /> __dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4400<br /> dev_queue_xmit include/linux/netdevice.h:3168 [inline]<br /> neigh_resolve_output net/core/neighbour.c:1514 [inline]<br /> neigh_resolve_output+0x5bc/0x950 net/core/neighbour.c:1494<br /> neigh_output include/net/neighbour.h:539 [inline]<br /> ip6_finish_output2+0xb1b/0x2070 net/ipv6/ip6_output.c:141<br /> __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]<br /> ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226<br /> NF_HOOK_COND include/linux/netfilter.h:303 [inline]<br /> ip6_output+0x1f8/0x540 net/ipv6/ip6_output.c:247<br /> dst_output include/net/dst.h:450 [inline]<br /> NF_HOOK include/linux/netfilter.h:314 [inline]<br /> NF_HOOK include/linux/netfilter.h:308 [inline]<br /> mld_sendpack+0x9f0/0x11d0 net/ipv6/mcast.c:1819<br /> mld_send_cr net/ipv6/mcast.c:2120 [inline]<br /> mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2651<br /> process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229<br /> process_scheduled_works kernel/workqueue.c:3310 [inline]<br /> worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391<br /> kthread+0x2c1/0x3a0 kernel/kthread.c:389<br /> ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147<br /> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244<br />