==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline]
BUG: KASAN: use-after-free in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1817
Write of size 8 at addr ffff8881d4fe31c8 by task syz.1.1095/4783
CPU: 1 PID: 4783 Comm: syz.1.1095 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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_del include/linux/list.h:791 [inline]
detach_timer kernel/time/timer.c:824 [inline]
expire_timers kernel/time/timer.c:1482 [inline]
__run_timers+0x7be/0xbe0 kernel/time/timer.c:1817
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x195/0x1c0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:539 [inline]
smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
RIP: 0033:0x7fcbf1f329fc
Code: 23 83 c0 01 44 39 d0 75 dc 48 89 f0 25 ff 1f 00 00 49 89 34 c1 41 88 3c 00 31 c0 c3 66 90 41 38 3c 10 74 0b 41 88 3c 10 31 c0 <49> 89 34 d1 c3 b8 01 00 00 00 c3 66 0f 1f 84 00 00 00 00 00 55 48
RSP: 002b:00007ffecc9568e8 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 00007fcbf2dbb720 RCX: 0000000000000000
RDX: 0000000000001ced RSI: ffffffff822d7ced RDI: 0000000000000000
RBP: ffffffff822d7ced R08: 00007fcbf2276000 R09: 00007fcbf2278000
R10: 00000000822d7cf1 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff822d7085 R15: 0000000000000008
The buggy address belongs to the page:
page:ffffea000753f8c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffea000753f8c8 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 0x146dc0(GFP_USER|__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
netdev_run_todo+0xc44/0xdf0 net/core/dev.c:9488
tun_detach drivers/net/tun.c:766 [inline]
tun_chr_close+0xc1/0x130 drivers/net/tun.c:3563
__fput+0x262/0x680 fs/file_table.c:281
task_work_run+0x140/0x170 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Memory state around the buggy address:
ffff8881d4fe3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881d4fe3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d4fe3180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8881d4fe3200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881d4fe3280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4783 Comm: syz.1.1095 Tainted: G B 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__hlist_del include/linux/list.h:791 [inline]
RIP: 0010:detach_timer kernel/time/timer.c:824 [inline]
RIP: 0010:expire_timers kernel/time/timer.c:1482 [inline]
RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1817
Code: 89 e7 e8 63 51 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 a5 66 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 32 51 3f 00 4d 89 65 00 eb 05 e8 77
RSP: 0000:ffff8881f6f09d60 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff1103a9fc639 RCX: dffffc0000000000
RDX: 0000000000000101 RSI: 0000000000000008 RDI: ffff8881d4fe31c8
RBP: ffff8881f6f09ec8 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6f09e20
R13: dead00000000012a R14: 1ffff1103a9fc638 R15: ffff8881d4fe31c8
FS: 000055558c920500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbf2286768 CR3: 00000001ebbff000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x195/0x1c0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:539 [inline]
smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
RIP: 0033:0x7fcbf1f329fc
Code: 23 83 c0 01 44 39 d0 75 dc 48 89 f0 25 ff 1f 00 00 49 89 34 c1 41 88 3c 00 31 c0 c3 66 90 41 38 3c 10 74 0b 41 88 3c 10 31 c0 <49> 89 34 d1 c3 b8 01 00 00 00 c3 66 0f 1f 84 00 00 00 00 00 55 48
RSP: 002b:00007ffecc9568e8 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 00007fcbf2dbb720 RCX: 0000000000000000
RDX: 0000000000001ced RSI: ffffffff822d7ced RDI: 0000000000000000
RBP: ffffffff822d7ced R08: 00007fcbf2276000 R09: 00007fcbf2278000
R10: 00000000822d7cf1 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff822d7085 R15: 0000000000000008
Modules linked in:
---[ end trace d740022216aff82b ]---
RIP: 0010:__hlist_del include/linux/list.h:791 [inline]
RIP: 0010:detach_timer kernel/time/timer.c:824 [inline]
RIP: 0010:expire_timers kernel/time/timer.c:1482 [inline]
RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1817
Code: 89 e7 e8 63 51 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 a5 66 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 32 51 3f 00 4d 89 65 00 eb 05 e8 77
RSP: 0000:ffff8881f6f09d60 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff1103a9fc639 RCX: dffffc0000000000
RDX: 0000000000000101 RSI: 0000000000000008 RDI: ffff8881d4fe31c8
RBP: ffff8881f6f09ec8 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6f09e20
R13: dead00000000012a R14: 1ffff1103a9fc638 R15: ffff8881d4fe31c8
FS: 000055558c920500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbf2286768 CR3: 00000001ebbff000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: 89 e7 mov %esp,%edi
2: e8 63 51 3f 00 call 0x3f516a
7: 4d 89 2c 24 mov %r13,(%r12)
b: 4d 85 ed test %r13,%r13
e: 74 2e je 0x3e
10: e8 a5 66 0f 00 call 0xf66ba
15: 49 83 c5 08 add $0x8,%r13
19: 4c 89 e8 mov %r13,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ef mov %r13,%rdi
33: e8 32 51 3f 00 call 0x3f516a
38: 4d 89 65 00 mov %r12,0x0(%r13)
3c: eb 05 jmp 0x43
3e: e8 .byte 0xe8
3f: 77 .byte 0x77