KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
df786149-6baf-4d5b-881b-445ec8d024d3	assessment-security	DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow	2026/05/31 13:16	2026/05/31 13:16	2026/05/31 14:06	6b4a844333e83556da95d61d7f207e7ef5cd4bc6
2d180e8b-e5dc-4d18-8a1f-ea3e566f6622	assessment-security		💥	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow	2026/05/14 16:54	2026/05/14 16:54	2026/05/14 16:54	6ccb967e465e832a7bfd7a116ad00d52a0923a5d	failed to run ["git" "pull" "origin" "HEAD" "--depth=1" "--allow-unrelated-histories"]: exit status 128 From /app/workdir/repo/linux * branch HEAD -> FETCH_HEAD Updating files: ... truncated to first 200 bytes; open job for full error
57d5c7f4-61f8-48bd-83ff-7047f425d85c	assessment-kcsan	Benign: ✅ Confident: ✅	❓	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow	2026/04/21 11:15	2026/04/21 11:15	2026/04/21 11:33	3f2e655b2741ba770abc65f58ac94b7e897edae8

================================================================== BUG: KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow write to 0xffffffff893aa488 of 304 bytes by interrupt on cpu 0: timekeeping_update_from_shadow+0x40d/0x440 kernel/time/timekeeping.c:829 __timekeeping_advance+0xa5d/0xc10 kernel/time/timekeeping.c:2532 timekeeping_advance kernel/time/timekeeping.c:2540 [inline] update_wall_time+0x21/0x50 kernel/time/timekeeping.c:2550 tick_do_update_jiffies64+0x169/0x1c0 kernel/time/tick-sched.c:149 tick_sched_do_timer kernel/time/tick-sched.c:253 [inline] tick_nohz_handler+0x8d/0x3d0 kernel/time/tick-sched.c:312 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x276/0x4f0 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x261/0x850 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705 check_access kernel/kcsan/core.c:753 [inline] __tsan_memset+0x1d9/0x1f0 kernel/kcsan/core.c:1335 cred_has_capability+0x40/0x2a0 security/selinux/hooks.c:1644 selinux_capable+0x31/0x40 security/selinux/hooks.c:2189 security_capable+0x7b/0x90 security/security.c:660 ns_capable_common kernel/capability.c:342 [inline] ns_capable+0x4c/0xb0 kernel/capability.c:363 __netlink_ns_capable net/netlink/af_netlink.c:852 [inline] netlink_ns_capable net/netlink/af_netlink.c:869 [inline] netlink_net_capable+0xaa/0xc0 net/netlink/af_netlink.c:900 rtnetlink_rcv_msg+0x14c/0x720 net/core/rtnetlink.c:6924 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7024 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x42e/0x490 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0x76/0x90 net/socket.c:2268 x64_sys_call+0x2d35/0x3020 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff893aa4f8 of 4 bytes by task 12748 on cpu 1: tk_xtime_coarse kernel/time/timekeeping.c:212 [inline] ktime_get_coarse_real_ts64_mg+0x89/0x1a0 kernel/time/timekeeping.c:2606 current_time+0x41/0x240 fs/inode.c:2376 need_cmtime_update fs/inode.c:2398 [inline] file_update_time_flags+0x83/0x2e0 fs/inode.c:2419 file_update_time+0x17/0x20 fs/inode.c:2449 shmem_file_write_iter+0x9c/0xf0 mm/shmem.c:3475 iter_file_splice_write+0x6c4/0xa80 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x156/0x2a0 fs/splice.c:1159 splice_direct_to_actor+0x311/0x670 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x119/0x1a0 fs/splice.c:1228 do_sendfile+0x382/0x650 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x2f5594d9 -> 0x2fee2b59 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 12748 Comm: syz.7.2273 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ==================================================================

Crashes (5):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Assets (help?)	Manager	Title
2026/05/24 11:52	upstream	4cbfe4502e3d	c69befb3	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow
2026/05/22 06:50	upstream	6779b50faa56	70ae9b03	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow
2026/05/13 01:42	upstream	c21b90f77687	a0949470	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow
2026/04/29 01:04	upstream	dca922e019dd	95008c03	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow
2026/04/21 11:15	upstream	b4e07588e743	3f2e655b	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in ktime_get_coarse_real_ts64_mg / timekeeping_update_from_shadow

Crashes (5):

Assets (help?)