syzbot


KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (4)

Status: moderation: reported on 2025/06/06 02:52
Subsystems: can
[Documentation on labels]
Reported-by: syzbot+11f6b0979969b5e96a04@syzkaller.appspotmail.com
First crash: 43d, last: 8d17h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv can 6 4 434d 479d 0/29 auto-obsoleted due to no activity on 2024/06/14 15:49
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (3) can 6 4 147d 132d 0/29 auto-obsoleted due to no activity on 2025/04/19 08:20
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (2) can 6 1 256d 256d 0/29 auto-obsoleted due to no activity on 2024/12/30 16:15

Sample crash report:
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 1:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x22b/0x270 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x3d8/0xae0 net/batman-adv/network-coding.c:720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 0:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:164
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00002209 -> 0x0000220a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 1:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x52b/0x630 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 0:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x52b/0x630 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0005e2d3 -> 0x0005e2d4

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10523 Comm: kworker/u8:48 Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 1:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline]
 batadv_tt_purge+0x2cd/0x610 net/batman-adv/translation-table.c:3510
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 0:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x52b/0x630 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x000bab5e -> 0x000bab5f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10493 Comm: kworker/u8:25 Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in can_rcv_filter / can_rcv_filter

read-write to 0xffff888101fb9158 of 8 bytes by interrupt on cpu 1:
 deliver net/can/af_can.c:576 [inline]
 can_rcv_filter+0xd9/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 rt6_uncached_list_add net/ipv6/route.c:146 [inline]
 icmp6_dst_alloc+0x2c7/0x330 net/ipv6/route.c:3342
 igmp6_send+0x505/0x870 net/ipv6/mcast.c:2241
 mld_mca_work+0x236/0x300 net/ipv6/mcast.c:2731
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888101fb9158 of 8 bytes by interrupt on cpu 0:
 deliver net/can/af_can.c:576 [inline]
 can_rcv_filter+0xd9/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:164
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000000bf021 -> 0x00000000000bf022

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 1:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x52b/0x630 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888100152b00 of 4 bytes by interrupt on cpu 0:
 can_can_gw_rcv+0x807/0x820 net/can/gw.c:566
 deliver net/can/af_can.c:575 [inline]
 can_rcv_filter+0xc4/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 j1939_sk_queue_session net/can/j1939/socket.c:107 [inline]
 j1939_sk_send_loop net/can/j1939/socket.c:1160 [inline]
 j1939_sk_sendmsg+0x906/0xc00 net/can/j1939/socket.c:1278
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x142/0x180 net/socket.c:727
 ____sys_sendmsg+0x345/0x4e0 net/socket.c:2566
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620
 __sys_sendmmsg+0x178/0x300 net/socket.c:2709
 __do_sys_sendmmsg net/socket.c:2736 [inline]
 __se_sys_sendmmsg net/socket.c:2733 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2733
 x64_sys_call+0x2f2f/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00117905 -> 0x00117907

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14709 Comm: syz.1.4896 Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in can_rcv_filter / can_rcv_filter

read-write to 0xffff888101fb9158 of 8 bytes by interrupt on cpu 1:
 deliver net/can/af_can.c:576 [inline]
 can_rcv_filter+0xd9/0x4f0 net/can/af_can.c:602
 can_receive+0x163/0x1c0 net/can/af_can.c:666
 can_rcv+0xed/0x190 net/can/af_can.c:690
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x120/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/10 19:06 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/07/10 19:06 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/07/07 15:58 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/06/21 22:05 upstream 3f75bfff44be d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/06/10 13:21 upstream f09079bd04a9 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/06/06 02:52 upstream e271ed52b344 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
* Struck through repros no longer work on HEAD.