------------[ cut here ]------------ WARNING: CPU: 1 PID: 6250 at net/mac80211/tx.c:5031 __ieee80211_beacon_update_cntdwn net/mac80211/tx.c:5031 [inline] WARNING: CPU: 1 PID: 6250 at net/mac80211/tx.c:5031 __ieee80211_beacon_get+0x1233/0x1600 net/mac80211/tx.c:5442 Modules linked in: CPU: 1 PID: 6250 Comm: syz.3.115 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__ieee80211_beacon_update_cntdwn net/mac80211/tx.c:5031 [inline] RIP: 0010:__ieee80211_beacon_get+0x1233/0x1600 net/mac80211/tx.c:5442 Code: 24 4c 89 e7 e8 de 8c c0 f7 45 31 f6 4c 8b bc 24 a0 00 00 00 e9 7a fe ff ff e8 d9 ca 82 f7 0f 0b e9 f6 f7 ff ff e8 cd ca 82 f7 <0f> 0b e9 48 fb ff ff e8 c1 ca 82 f7 48 c7 c7 00 86 64 8e 4c 89 e6 RSP: 0018:ffffc900001f0a18 EFLAGS: 00010246 RAX: ffffffff8a045733 RBX: ffffffff8a044536 RCX: ffff88802d5a5a00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88802d5a5a00 R09: 0000000000000003 R10: 0000000000000007 R11: 0000000000000100 R12: ffff88805bac23c0 R13: dffffc0000000000 R14: ffff88805bac28b0 R15: ffff88805c4ecc24 FS: 00007f861bc066c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3a9fa8 CR3: 0000000074c2d000 CR4: 00000000003526e0 Call Trace: ieee80211_beacon_get_tim+0xbf/0x580 net/mac80211/tx.c:5569 ieee80211_beacon_get include/net/mac80211.h:5440 [inline] mac80211_hwsim_beacon_tx+0x3c7/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2265 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1814 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010 Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 51 f6 cd f6 e8 7c 03 ff f6 fb bf 01 00 00 00 f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f RSP: 0018:ffffc9000c05ef00 EFLAGS: 00000286 RAX: 358b429cab4e2500 RBX: 0000000000000000 RCX: 358b429cab4e2500 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffffc9000c05efb0 R08: ffffffff911c5507 R09: 1ffffffff2238aa0 R10: dffffc0000000000 R11: fffffbfff2238aa1 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200180bde0 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692 RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x30/0x90 kernel/kcov.c:313 Code: 04 24 65 48 8b 15 00 90 7c 7e 65 8b 0d 01 90 7c 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 <8b> 8a f8 15 00 00 83 f9 03 75 47 48 8b 8a 00 16 00 00 44 8b 8a fc RSP: 0018:ffffc9000c05f078 EFLAGS: 00000246 RAX: ffffffff8475f6d6 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88802d5a5a00 RSI: 0000000000000000 RDI: 0000000000000010 RBP: ffffc9000c05f200 R08: ffff888021b6111b R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000002 R12: 0000000000000330 R13: 1ffff1100436c223 R14: 0000000000000340 R15: dffffc0000000000 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:263 [inline] sys_imageblit+0x19e6/0x23b0 drivers/video/fbdev/core/sysimgblt.c:323 drm_fbdev_generic_defio_imageblit+0x2c/0x110 drivers/gpu/drm/drm_fbdev_generic.c:37 bit_putcs+0x1863/0x1bf0 drivers/video/fbdev/core/bitblit.c:-1 fbcon_putcs+0x35c/0x520 drivers/video/fbdev/core/fbcon.c:1299 do_update_region+0x4ab/0x620 drivers/tty/vt/vt.c:623 csi_J+0xa1b/0xe80 drivers/tty/vt/vt.c:1539 do_con_trol drivers/tty/vt/vt.c:2234 [inline] do_con_write+0x3836/0x6e50 drivers/tty/vt/vt.c:2905 con_write+0x24/0x40 drivers/tty/vt/vt.c:3245 process_output_block drivers/tty/n_tty.c:580 [inline] n_tty_write+0xd34/0x11e0 drivers/tty/n_tty.c:2395 iterate_tty_write drivers/tty/tty_io.c:1017 [inline] file_tty_write+0x54b/0x980 drivers/tty/tty_io.c:1088 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x46c/0x990 fs/read_write.c:584 ksys_write+0x150/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f861ad9cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f861bc06028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f861b016270 RCX: 00007f861ad9cdd9 RDX: 0000000000001006 RSI: 0000200000002080 RDI: 0000000000000008 RBP: 00007f861ae32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f861b016308 R14: 00007f861b016270 R15: 00007ffcb0d41ae8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 43 c6 44 37 04 f8 movb $0xf8,0x4(%r15,%r14,1) 8: 74 0b je 0x15 a: 0f 0b ud2 c: 48 f7 03 08 00 00 00 testq $0x8,(%rbx) 13: 74 6f je 0x84 15: bf 01 00 00 00 mov $0x1,%edi 1a: e8 51 f6 cd f6 call 0xf6cdf670 1f: e8 7c 03 ff f6 call 0xf6ff03a0 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 f1 b4 ff ff call 0xffffb520 <-- trapping instruction 2f: 43 c6 44 37 08 00 movb $0x0,0x8(%r15,%r14,1) 35: 48 c7 44 24 40 00 00 movq $0x0,0x40(%rsp) 3c: 00 00 3e: 9c pushf 3f: 8f .byte 0x8f