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: mm/memcontrol: fix data-race on reading jiffies_64
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 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-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 772d, last: 16h28m
▶ ▼ ✨ 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 811d 1038d 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 1:
 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:2074 [inline]
 __hrtimer_run_queues+0x1f8/0x510 kernel/time/hrtimer.c:2131
 hrtimer_interrupt+0x27b/0x860 kernel/time/hrtimer.c:2250
 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
 copy_page_range+0x128b/0x33c0 mm/memory.c:-1
 dup_mmap+0x874/0x10c0 mm/mmap.c:1819
 dup_mm kernel/fork.c:1543 [inline]
 copy_mm+0xf5/0x350 kernel/fork.c:1595
 copy_process+0x108a/0x2360 kernel/fork.c:2311
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2771
 __do_sys_clone kernel/fork.c:2913 [inline]
 __se_sys_clone kernel/fork.c:2897 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2897
 x64_sys_call+0x2479/0x2550 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86e07a00 of 8 bytes by task 19232 on cpu 0:
 mem_cgroup_flush_stats_ratelimited+0x29/0x50 mm/memcontrol.c:788
 count_shadow_nodes+0x6a/0x250 mm/workingset.c:689
 do_shrink_slab+0x61/0x650 mm/shrinker.c:391
 shrink_slab_memcg mm/shrinker.c:562 [inline]
 shrink_slab+0x53b/0x8e0 mm/shrinker.c:640
 shrink_node_memcgs mm/vmscan.c:6222 [inline]
 shrink_node+0x6b8/0x2000 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
 mem_cgroup_force_empty mm/memcontrol-v1.c:1852 [inline]
 mem_cgroup_force_empty_write+0x77/0x100 mm/memcontrol-v1.c:1868
 cgroup_file_write+0x197/0x350 kernel/cgroup/cgroup.c:4412
 kernfs_fop_write_iter+0x1d2/0x2e0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57f/0x9a0 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000100005109 -> 0x000000010000510a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 19232 Comm: syz.4.3470 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================

Crashes (822):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2026/09/13 09:56 upstream 2f0c1cf72f46 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 00:08 upstream 5225b8eec4c9 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
2026/09/11 23:28 upstream 3026c6e4f223 b6a5eeb7 .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
2026/09/09 07:34 upstream 893e11787f78 8387c273 .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
2026/09/08 09:45 upstream 28924df2a08f 680aa3e1 .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
2026/09/07 22:31 upstream df2908090cda 680aa3e1 .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
2026/09/06 23:12 upstream 88405f0ad1d5 4f7b22a0 .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
2026/09/06 13:00 upstream 1fc5a74b108f 4f7b22a0 .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
2026/09/05 05:58 upstream bc35965f6940 4f7b22a0 .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
2026/09/04 03:06 upstream 8ab1afb2eb24 801f0966 .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.