KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2)

Status: moderation: reported on 2024/08/30 11:59
Subsystems: kernel
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+ced4d9a8cadb5ef3adae@syzkaller.appspotmail.com
Fix commit: c20cf1c3c8cd mm/memcontrol: fix data-race on reading jiffies_64
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-gce-arm64 ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce]
First crash: 788d, last: 3d23h
▶ ▼ ✨ AI Jobs (5)
ID Workflow Result Correct Bug Created Started Finished Revision
0066b235 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ ❓ KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2) 2026/05/31 17:21 2026/05/31 17:21 2026/05/31 17:24 6b4a8443
47f163b6 assessment-security 💥 KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2) 2026/05/15 05:51 2026/05/15 05:51 2026/05/15 05:52 6ccb967e
21ff92f9 repro ❓ KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2) 2026/03/07 04:28 2026/03/07 04:28 2026/03/07 04:31 31e9c887
be02103c assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2) 2026/02/24 18:42 2026/02/24 18:42 2026/02/24 18:46 305c0ec5
17baa52a assessment-kcsan 💥 KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 (2) 2026/01/09 22:46 2026/01/09 22:46 2026/01/09 22:46 75199160
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[PATCH] mm/memcontrol: fix data-race on reading jiffies_64 4 (4) 2026/08/27 14:59
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 kernel 6 334 827d 1053d 0/29 auto-obsoleted due to no activity on 2024/08/19 05:50

Sample crash report:
==================================================================
BUG: KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64

read-write to 0xffffffff86e07a00 of 8 bytes by interrupt on cpu 0:
 tick_do_update_jiffies64+0x113/0x1c0 kernel/time/tick-sched.c:118
 tick_sched_do_timer kernel/time/tick-sched.c:253 [inline]
 tick_nohz_handler+0x88/0x380 kernel/time/tick-sched.c:310
 __run_hrtimer kernel/time/hrtimer.c:2075 [inline]
 __hrtimer_run_queues+0x1f8/0x510 kernel/time/hrtimer.c:2132
 hrtimer_interrupt+0x27b/0x860 kernel/time/hrtimer.c:2251
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:123 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:221
 spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
 __uart_port_unlock_irqrestore include/linux/serial_core.h:622 [inline]
 univ8250_console_device_unlock+0x36/0x40 drivers/tty/serial/8250/8250_core.c:420
 nbcon_emit_one kernel/printk/nbcon.c:1165 [inline]
 nbcon_kthread_func+0x5e0/0x6d0 kernel/printk/nbcon.c:1271
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86e07a00 of 8 bytes by task 15196 on cpu 1:
 mem_cgroup_flush_stats_ratelimited+0x29/0x50 mm/memcontrol.c:788
 count_shadow_nodes+0x6a/0x250 mm/workingset.c:689
 do_shrink_slab+0x61/0x640 mm/shrinker.c:391
 shrink_slab_memcg mm/shrinker.c:562 [inline]
 shrink_slab+0x53b/0x8d0 mm/shrinker.c:640
 shrink_node_memcgs mm/vmscan.c:6222 [inline]
 shrink_node+0x6b3/0x1ff0 mm/vmscan.c:6264
 shrink_zones mm/vmscan.c:6503 [inline]
 do_try_to_free_pages+0x408/0xca0 mm/vmscan.c:6565
 try_to_free_mem_cgroup_pages+0x201/0x420 mm/vmscan.c:6887
 try_charge_memcg+0x422/0xae0 mm/memcontrol.c:2718
 charge_memcg+0x16f/0x220 mm/memcontrol.c:5210
 __mem_cgroup_charge+0x28/0xb0 mm/memcontrol.c:5227
 mem_cgroup_charge include/linux/memcontrol.h:662 [inline]
 shmem_alloc_and_add_folio mm/shmem.c:1988 [inline]
 shmem_get_folio_gfp+0x49a/0xd80 mm/shmem.c:2531
 shmem_fault+0xf6/0x250 mm/shmem.c:2732
 __do_fault mm/memory.c:5565 [inline]
 do_read_fault mm/memory.c:6000 [inline]
 do_fault mm/memory.c:6134 [inline]
 do_pte_missing mm/memory.c:4700 [inline]
 handle_pte_fault mm/memory.c:6558 [inline]
 __handle_mm_fault mm/memory.c:6707 [inline]
 handle_mm_fault+0x1a8e/0x3c60 mm/memory.c:6876
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x12e4/0x1ea0 mm/gup.c:1428
 __get_user_pages_locked mm/gup.c:1692 [inline]
 get_dump_page+0xb4/0x240 mm/gup.c:2192
 dump_user_range+0x15c/0x920 fs/coredump.c:1593
 elf_core_dump+0x2183/0x2310 fs/binfmt_elf.c:2106
 coredump_write fs/coredump.c:1150 [inline]
 do_coredump fs/coredump.c:1235 [inline]
 vfs_coredump+0x4247/0x4800 fs/coredump.c:1310
 get_signal+0xd2e/0xf00 kernel/signal.c:3097
 arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x14d/0x610 kernel/entry/common.c:152
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595

value changed: 0x00000001000004c1 -> 0x00000001000004c2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 15196 Comm: syz.1.2418 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
==================================================================

Crashes (834):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/23 14:52 upstream a1c2b1da93f5 d566bfda .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/22 00:16 upstream a804c5742bff 4ba27f85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/19 17:21 upstream c03c1a14507d 72cdc28d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/19 11:15 upstream c03c1a14507d 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/17 09:25 upstream 70dd4ee72eb2 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/16 05:13 upstream 9aa622dbaab8 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/14 19:35 upstream 4056b3c9d3c9 1a71827b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/14 04:02 upstream ca3e345926b0 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/13 19:39 upstream 24a19b953e2a 5a1eeac4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/13 03:38 upstream 24a19b953e2a 745a967f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/12 04:23 upstream b88c841d1164 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/11 08:09 upstream a5ebb76233b7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/10 05:41 upstream fc1c25014ff8 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/09 22:30 upstream af32da41b032 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/09 01:07 upstream 6c377d19d4a5 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/08 07:37 upstream 7b63ef2d55f2 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/06 23:28 upstream 69f80fef3153 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/06 15:59 upstream 2c3418fffa9d f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/06 01:32 upstream 67f0943b394d f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/05 03:53 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/04 10:33 upstream 6addb4f38557 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/04 02:38 upstream a74306e2e676 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/03 16:54 upstream e767a4ea70a3 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/01 19:12 upstream d24e8ac715de f5cdae2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/10/01 11:56 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/30 08:48 upstream 551c722f4080 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/29 15:16 upstream 6f8319e3e9a4 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/26 23:20 upstream fddfc3ec3179 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/26 12:05 upstream 6812ce4e4379 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/25 07:13 upstream f49a343b305c f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/24 01:46 upstream 62f4c998b297 0281b448 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/23 21:32 upstream fe2ec83746e5 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/21 12:26 upstream 93f51579e7df 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/20 20:24 upstream 518e5b794c06 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/19 20:48 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/18 23:57 upstream 17e7b8eacf4c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/18 19:06 upstream 5dd1818b15d9 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/17 07:42 upstream 238650ef6c7c 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/16 07:32 upstream 9b87fdc9af2f 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/16 00:31 upstream f6e7b42bf05b 2daa4bb5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/15 12:44 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/14 15:05 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/14 11:38 upstream 704340f1cd0d 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/09/13 23:31 upstream d681d7ef617e 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/05/30 23:44 upstream 9d87d0fc8c8e 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/05/15 02:52 upstream 66182ca873a4 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/03/06 05:33 upstream 5ee8dbf54602 31e9c887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/02/24 14:45 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2026/01/09 16:20 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
2024/08/30 11:58 upstream 20371ba12063 ee2602b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64
* Struck through repros no longer work on HEAD.