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KASAN: slab-use-after-free Write in __run_timers

Status: closed as invalid on 2025/03/30 10:14
Subsystems: net
[Documentation on labels]
First crash: 33d, last: 33d
▶ ▼ Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: invalid-access Write in __run_timers kernel 8 1503d 1510d 0/28 auto-closed as invalid on 2021/05/20 13:15
android-6-1 KASAN: use-after-free Write in __run_timers origin:lts C 125 27d 122d 0/2 upstream: reported C repro on 2024/12/01 07:19
upstream KMSAN: uninit-value in __run_timers (3) reiserfs C error 4 575d 612d 0/28 auto-obsoleted due to no activity on 2024/01/10 00:11
android-54 KASAN: use-after-free Write in __run_timers (2) C 449 11h31m 36d 0/2 upstream: reported C repro on 2025/02/25 14:17
android-54 KASAN: use-after-free Write in __run_timers syz 449 274d 1726d 0/2 auto-obsoleted due to no activity on 2024/09/11 00:16
android-54 KASAN: slab-out-of-bounds Write in __run_timers 4 1374d 1564d 0/2 auto-closed as invalid on 2021/10/26 12:53
upstream BUG: unable to handle kernel NULL pointer dereference in __run_timers arm 1 308d 304d 0/28 auto-obsoleted due to no activity on 2024/08/27 10:03

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in hlist_move_list include/linux/list.h:1110 [inline]
BUG: KASAN: slab-use-after-free in collect_expired_timers kernel/time/timer.c:1861 [inline]
BUG: KASAN: slab-use-after-free in __run_timers+0x8b0/0x930 kernel/time/timer.c:2396
Write of size 8 at addr ffff88807bae1250 by task syz.6.772/12611

CPU: 1 UID: 0 PID: 12611 Comm: syz.6.772 Tainted: G     U             6.14.0-rc4-syzkaller-00199-g76544811c850 #0
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xd9/0x110 mm/kasan/report.c:634
 hlist_move_list include/linux/list.h:1110 [inline]
 collect_expired_timers kernel/time/timer.c:1861 [inline]
 __run_timers+0x8b0/0x930 kernel/time/timer.c:2396
 __run_timer_base kernel/time/timer.c:2426 [inline]
 __run_timer_base kernel/time/timer.c:2418 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2435
 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2445
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
 __do_softirq kernel/softirq.c:595 [inline]
 invoke_softirq kernel/softirq.c:435 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x57/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0033:0x7fc9a26665c5
Code: 72 f3 48 83 e8 08 48 39 f2 73 17 66 2e 0f 1f 84 00 00 00 00 00 48 8b 70 f8 48 83 e8 08 48 39 f2 72 f3 48 39 c3 73 3e 48 89 33 <48> 83 c3 08 48 8b 70 f8 48 89 08 48 8b 0b 49 8b 14 24 eb bf 48 39
RSP: 002b:00007ffc3d88f700 EFLAGS: 00000283
RAX: 00007fc9a1e22a90 RBX: 00007fc9a1e20600 RCX: ffffffff81f18fa0
RDX: ffffffff81f18fa0 RSI: ffffffff81f18fa0 RDI: 00007fc9a1e230e0
RBP: 00007fc9a1e20088 R08: 00007fc9a1e218b0 R09: 00007fc9a2992000
R10: 00007fc9a1dff008 R11: 0000000000000008 R12: 00007fc9a1e20080
R13: 000000000000001a R14: ffffffffffffffff R15: 00007fc9a1dff008
 </TASK>

Allocated by task 12590:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x21c/0x510 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 ops_init+0x77/0x5f0 net/core/net_namespace.c:128
 setup_net+0x21f/0x860 net/core/net_namespace.c:362
 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:516
 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
 ksys_unshare+0x45d/0xa40 kernel/fork.c:3342
 __do_sys_unshare kernel/fork.c:3413 [inline]
 __se_sys_unshare kernel/fork.c:3411 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3411
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 4535:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 ops_free_list+0x14e/0x410 net/core/net_namespace.c:187
 cleanup_net+0x619/0xb30 net/core/net_namespace.c:656
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88807bae0000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4688 bytes inside of
 freed 8192-byte region [ffff88807bae0000, ffff88807bae2000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bae0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b042280 ffffea000170f600 dead000000000002
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042280 ffffea000170f600 dead000000000002
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001eeb801 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5512, tgid 5512 (dhcpcd-run-hook), ts 47204899451, free_ts 47176274194
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
 tomoyo_init_log+0xcb3/0x2170 security/tomoyo/audit.c:264
 tomoyo_supervisor+0x313/0x1380 security/tomoyo/common.c:2198
 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x193/0x210 security/tomoyo/environ.c:63
 tomoyo_environ security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0xed4/0x20c0 security/tomoyo/domain.c:888
 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline]
 tomoyo_bprm_check_security+0x12e/0x1d0 security/tomoyo/tomoyo.c:92
 security_bprm_check+0x1b9/0x1e0 security/security.c:1302
 search_binary_handler fs/exec.c:1765 [inline]
 exec_binprm fs/exec.c:1807 [inline]
 bprm_execve fs/exec.c:1859 [inline]
 bprm_execve+0x832/0x16d0 fs/exec.c:1835
 do_execveat_common.isra.0+0x4a2/0x610 fs/exec.c:1966
page last free pid 5511 tgid 5511 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 __put_partials+0x14c/0x170 mm/slub.c:3153
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_noprof+0x1cd/0x510 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 tomoyo_add_entry security/tomoyo/common.c:2132 [inline]
 tomoyo_supervisor+0x46c/0x1380 security/tomoyo/common.c:2204
 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x193/0x210 security/tomoyo/environ.c:63
 tomoyo_environ security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0xed4/0x20c0 security/tomoyo/domain.c:888
 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline]
 tomoyo_bprm_check_security+0x12e/0x1d0 security/tomoyo/tomoyo.c:92
 security_bprm_check+0x1b9/0x1e0 security/security.c:1302
 search_binary_handler fs/exec.c:1765 [inline]
 exec_binprm fs/exec.c:1807 [inline]
 bprm_execve fs/exec.c:1859 [inline]
 bprm_execve+0x832/0x16d0 fs/exec.c:1835
 do_execveat_common.isra.0+0x4a2/0x610 fs/exec.c:1966
 do_execve fs/exec.c:2040 [inline]
 __do_sys_execve fs/exec.c:2116 [inline]
 __se_sys_execve fs/exec.c:2111 [inline]
 __x64_sys_execve+0x8c/0xb0 fs/exec.c:2111
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807bae1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bae1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807bae1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88807bae1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bae1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/28 17:06 upstream 76544811c850 1e7a43e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Write in __run_timers
* Struck through repros no longer work on HEAD.