WARNING in max_vclocks_store

Status: upstream: reported C repro on 2026/09/27 10:42
Reported-by: syzbot+5a62e9c7db1adbb6874e@syzkaller.appspotmail.com
First crash: 1d14h, last: 1d09h
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in max_vclocks_store mm net -1 syz, C 3 394d 630d 29/29 fixed on 2025/10/29 21:02
linux-6.6 WARNING in max_vclocks_store -1 syz, C 5 1d07h 42d 0/2 upstream: reported C repro on 2026/08/17 09:49
linux-5.15 WARNING in max_vclocks_store -1 syz, C 4 1d11h 10d 0/3 upstream: reported C repro on 2026/09/18 02:44

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4500 at mm/page_alloc.c:5634 __alloc_pages+0xd0/0x544 mm/page_alloc.c:5634
Modules linked in:
CPU: 0 PID: 4500 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __alloc_pages+0xd0/0x544 mm/page_alloc.c:5634
lr : __alloc_pages+0xac/0x544 mm/page_alloc.c:5628
sp : ffff8000216077a0
x29: ffff800021607870 x28: 1fffe0001a5beb12 x27: 1fffe0001a5beb12
x26: ffff8000216077c0 x25: dfff800000000000 x24: ffff7000042c0ef8
x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000040dc0
x20: 0000000000000000 x19: 000000000000000b x18: 0000000000000000
x17: 0000000000000000 x16: ffff800011bb65f8 x15: ffff800018508000
x14: 0000000000000005 x13: 1ffff000042c0efc x12: 0000000000000000
x11: 0000000000000000 x10: ffff7000042c0f01 x9 : 0000000000000001
x8 : ffff800017d98000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff8000186c6148 x4 : 0000000000000000 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 __alloc_pages+0xd0/0x544 mm/page_alloc.c:5634
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x9c/0x1dc mm/slab_common.c:1077
 __do_kmalloc_node mm/slab_common.c:924 [inline]
 __kmalloc+0x12c/0x180 mm/slab_common.c:949
 kmalloc_array include/linux/slab.h:615 [inline]
 kcalloc include/linux/slab.h:646 [inline]
 max_vclocks_store+0x1f4/0x2f8 drivers/ptp/ptp_sysfs.c:286
 dev_attr_store+0x6c/0x90 drivers/base/core.c:2388
 sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140
 kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3c8/0x7c8 fs/read_write.c:584
 ksys_write+0x12c/0x228 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 1794
hardirqs last  enabled at (1793): [<ffff8000088ea5c8>] ___slab_alloc+0xca4/0xe90 mm/slub.c:3088
hardirqs last disabled at (1794): [<ffff800011bb2834>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (1776): [<ffff800008031254>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (1774): [<ffff800008031220>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/27 11:26 linux-6.1.y 1a8763b93150 a3c7249d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in max_vclocks_store
2026/09/27 11:02 linux-6.1.y 1a8763b93150 a3c7249d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in max_vclocks_store
2026/09/27 16:00 linux-6.1.y 1a8763b93150 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in max_vclocks_store
2026/09/27 15:59 linux-6.1.y 1a8763b93150 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in max_vclocks_store
2026/09/27 10:42 linux-6.1.y 1a8763b93150 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in max_vclocks_store
2026/09/27 10:41 linux-6.1.y 1a8763b93150 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in max_vclocks_store
* Struck through repros no longer work on HEAD.