syzbot

 sign-in | mailing list | source | docs
🐞 Open [77]
🐞 Fixed [22]
🐞 Invalid [338]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

KASAN: use-after-free Write in enqueue_timer (2)

Status: upstream: reported C repro on 2025/02/17 15:17
Reported-by: syzbot+02af8de0847c4564d39d@syzkaller.appspotmail.com
First crash: 75d, last: 13m
▶ ▼ Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 KASAN: use-after-free Write in enqueue_timer C 4288 281d 788d 0/2 auto-obsoleted due to no activity on 2024/09/11 16:22
upstream KASAN: use-after-free Write in enqueue_timer net 1 877d 877d 22/28 fixed on 2023/02/24 13:50
android-5-15 KASAN: use-after-free Write in enqueue_timer 1 448d 448d 0/2 auto-obsoleted due to no activity on 2024/04/17 12:01
android-6-1 KASAN: use-after-free Write in enqueue_timer origin:lts C 88 27d 259d 0/2 upstream: reported C repro on 2024/07/25 13:16
upstream KASAN: slab-use-after-free Write in enqueue_timer net 18 695d 711d 0/28 auto-obsoleted due to no activity on 2023/08/22 15:17
upstream KASAN: invalid-access Write in enqueue_timer ext4 20 1492d 1514d 0/28 auto-closed as invalid on 2021/07/08 00:48

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
Write of size 8 at addr ffff8881d7fbf1c8 by task kworker/0:1/13

CPU: 0 PID: 13 Comm: kworker/0:1 Not tainted 5.4.290-syzkaller-00002-g41adfeb3d639 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 hlist_add_head include/linux/list.h:814 [inline]
 enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
 __internal_add_timer kernel/time/timer.c:554 [inline]
 internal_add_timer+0x240/0x430 kernel/time/timer.c:604
 __mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065
 mod_delayed_work_on+0xff/0x190 kernel/workqueue.c:1736
 mod_delayed_work include/linux/workqueue.h:531 [inline]
 addrconf_mod_dad_work+0x79/0x120 net/ipv6/addrconf.c:326
 addrconf_dad_work+0xa80/0x16f0 net/ipv6/addrconf.c:4189
 process_one_work+0x765/0xd20 kernel/workqueue.c:2290
 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

The buggy address belongs to the page:
page:ffffea00075fefc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x46dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ZERO)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 __alloc_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 kmalloc_order mm/slab_common.c:1342 [inline]
 kmalloc_order_trace+0x2a/0x100 mm/slab_common.c:1358
 __kmalloc_node include/linux/slab.h:422 [inline]
 kmalloc_node include/linux/slab.h:599 [inline]
 kvmalloc_node+0x7e/0xf0 mm/util.c:596
 kvmalloc include/linux/mm.h:761 [inline]
 kvzalloc include/linux/mm.h:769 [inline]
 alloc_netdev_mqs+0x85/0xc70 net/core/dev.c:9629
 tun_set_iff+0x51f/0xdc0 drivers/net/tun.c:2893
 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3187
 do_vfs_ioctl+0x742/0x1720 fs/ioctl.c:47
 ksys_ioctl fs/ioctl.c:742 [inline]
 __do_sys_ioctl fs/ioctl.c:749 [inline]
 __se_sys_ioctl fs/ioctl.c:747 [inline]
 __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 device_release+0x6b/0x190 drivers/base/core.c:1776
 kobject_cleanup lib/kobject.c:716 [inline]
 kobject_release lib/kobject.c:747 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e6/0x2f0 lib/kobject.c:764
 tun_set_iff+0x870/0xdc0 drivers/net/tun.c:2924
 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3187
 do_vfs_ioctl+0x742/0x1720 fs/ioctl.c:47
 ksys_ioctl fs/ioctl.c:742 [inline]
 __do_sys_ioctl fs/ioctl.c:749 [inline]
 __se_sys_ioctl fs/ioctl.c:747 [inline]
 __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881d7fbf080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d7fbf100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d7fbf180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881d7fbf200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d7fbf280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (3274):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/28 01:40 android12-5.4 41adfeb3d639 6c09fb82 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/02/17 15:09 android12-5.4 39762b7a60e9 4121cf9d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/03/25 00:53 android12-5.4 41adfeb3d639 875573af .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/02/13 04:49 android12-5.4 39762b7a60e9 b27c2402 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 20:53 android12-5.4 41adfeb3d639 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 17:52 android12-5.4 41adfeb3d639 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 15:37 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 15:20 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 12:18 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 10:47 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 09:17 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 06:05 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 05:04 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 03:40 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 00:34 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 23:09 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 19:09 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 18:02 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 16:39 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 14:34 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 13:22 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 11:08 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 10:06 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 08:25 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 07:19 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 07:05 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 03:10 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/09 01:02 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 22:17 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 21:00 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 19:38 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 18:20 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 16:58 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 15:44 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 14:41 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 13:07 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 12:02 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/08 09:09 android12-5.4 41adfeb3d639 a2ada0e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in enqueue_timer
2025/02/24 01:25 android12-5.4 6b07fcd94a6a d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Write in enqueue_timer
2025/04/10 19:50 android12-5.4 41adfeb3d639 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/10 16:51 android12-5.4 41adfeb3d639 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/10 07:30 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/10 02:03 android12-5.4 41adfeb3d639 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/09 22:08 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/09 21:41 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/09 20:29 android12-5.4 41adfeb3d639 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/09 05:36 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/04/08 13:13 android12-5.4 41adfeb3d639 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: slab-out-of-bounds Write in enqueue_timer
2025/02/28 07:34 android12-5.4 6b07fcd94a6a 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan BUG: unable to handle kernel paging request in enqueue_timer
2025/02/23 19:30 android12-5.4 6b07fcd94a6a d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: out-of-bounds Write in enqueue_timer
* Struck through repros no longer work on HEAD.