[moderation] [kernel?] KCSAN: data-race in ktime_get_seconds / timekeeping_update_from_shadow

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ec2df4364666 Merge tag 'spi-fix-v6.16-rc7' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=176f2034580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c0dd0a92e88efc24
dashboard link: https://syzkaller.appspot.com/bug?extid=ef1ef7bda4f27bf85b1a
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
CC: [jst...@google.com linux-...@vger.kernel.org sb...@kernel.org tg...@linutronix.de]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/29b468ddeacc/disk-ec2df436.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/996435d5d9de/vmlinux-ec2df436.xz
kernel image: https://storage.googleapis.com/syzbot-assets/170fc9879e1c/bzImage-ec2df436.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ef1ef7...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in ktime_get_seconds / timekeeping_update_from_shadow

write to 0xffffffff88e730c8 of 280 bytes by interrupt on cpu 1:
timekeeping_update_from_shadow+0x280/0x2b0 kernel/time/timekeeping.c:705
timekeeping_advance+0xa07/0xba0 kernel/time/timekeeping.c:2242
update_wall_time+0x10/0x30 kernel/time/timekeeping.c:2253
tick_do_update_jiffies64+0x169/0x1c0 kernel/time/tick-sched.c:149
tick_sched_do_timer kernel/time/tick-sched.c:232 [inline]
tick_nohz_handler+0x7f/0x2d0 kernel/time/tick-sched.c:290
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x20c/0x5a0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
console_flush_all+0x55b/0x730 arch/x86/include/asm/irqflags.h:-1
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xa1/0x330 kernel/printk/printk.c:3325
vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450
vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
_printk+0x79/0xa0 kernel/printk/printk.c:2475
kauditd_printk_skb kernel/audit.c:546 [inline]
kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:581
kauditd_send_queue+0x273/0x2c0 kernel/audit.c:766
kauditd_thread+0x421/0x630 kernel/audit.c:890
kthread+0x486/0x510 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 to 0xffffffff88e73108 of 8 bytes by task 5719 on cpu 0:
ktime_get_seconds+0x3a/0x60 kernel/time/timekeeping.c:944
tcp_store_ts_recent net/ipv4/tcp_input.c:3826 [inline]
__tcp_replace_ts_recent net/ipv4/tcp_input.c:3831 [inline]
tcp_replace_ts_recent net/ipv4/tcp_input.c:3849 [inline]
tcp_ack+0x65b/0x3040 net/ipv4/tcp_input.c:4010
tcp_rcv_established+0x496/0xef0 net/ipv4/tcp_input.c:6312
tcp_v4_do_rcv+0x672/0x740 net/ipv4/tcp_ipv4.c:1925
sk_backlog_rcv+0x71/0x190 include/net/sock.h:1148
__release_sock+0xb4/0x130 net/core/sock.c:3213
release_sock+0x44/0x150 net/core/sock.c:3767
sk_stream_wait_memory+0x461/0x860 net/core/stream.c:145
tcp_sendmsg_locked+0xad4/0x2c10 net/ipv4/tcp.c:1349
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1396
inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x102/0x180 net/socket.c:727
__sys_sendto+0x268/0x330 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0x76/0x90 net/socket.c:2183
x64_sys_call+0x2eb6/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:45
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: 0x0000000000000067 -> 0x0000000000000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5719 Comm: syz.0.690 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.