==================================================================
BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: slab-out-of-bounds in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
Write of size 8 at addr ffff8881e6a871c8 by task ksoftirqd/1/17
CPU: 1 PID: 17 Comm: ksoftirqd/1 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_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
call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x879/0xbe0 kernel/time/timer.c:1817
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
run_ksoftirqd+0x1f/0x30 kernel/softirq.c:603
smpboot_thread_fn+0x545/0x930 kernel/smpboot.c:165
kthread+0x2da/0x360 kernel/kthread.c:288
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Allocated by task 6708:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
__kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
__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]
kvmalloc_array include/linux/mm.h:779 [inline]
__ptr_ring_init_queue_alloc include/linux/ptr_ring.h:470 [inline]
ptr_ring_resize include/linux/ptr_ring.h:593 [inline]
tun_attach+0x81e/0x14b0 drivers/net/tun.c:853
tun_net_init+0x409/0x540 drivers/net/tun.c:1069
register_netdevice+0x1c0/0x12a0 net/core/dev.c:9139
tun_set_iff+0x7f7/0xdc0 drivers/net/tun.c:2922
__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
Freed by task 6708:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
kasan_set_free_info mm/kasan/common.c:345 [inline]
__kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook mm/slub.c:1494 [inline]
slab_free mm/slub.c:3080 [inline]
kfree+0x123/0x370 mm/slub.c:4071
tun_detach drivers/net/tun.c:763 [inline]
tun_chr_close+0x8f/0x130 drivers/net/tun.c:3563
__fput+0x262/0x680 fs/file_table.c:281
task_work_run+0x140/0x170 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xcaf/0x2bc0 kernel/exit.c:861
do_group_exit+0x138/0x300 kernel/exit.c:984
get_signal+0xdb1/0x1440 kernel/signal.c:2738
do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
The buggy address belongs to the object at ffff8881e6a86000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 456 bytes to the right of
4096-byte region [ffff8881e6a86000, ffff8881e6a87000)
The buggy address belongs to the page:
page:ffffea00079aa000 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c280
raw: 0000000000000000 0000000000040004 00000001ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
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_slab_page+0x39/0x3c0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x97/0x440 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x2fe/0x490 mm/slub.c:2667
__slab_alloc+0x62/0xa0 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
__kmalloc+0x19b/0x2e0 mm/slub.c:3909
__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]
kvmalloc_array include/linux/mm.h:779 [inline]
__ptr_ring_init_queue_alloc include/linux/ptr_ring.h:470 [inline]
ptr_ring_resize include/linux/ptr_ring.h:593 [inline]
tun_attach+0x81e/0x14b0 drivers/net/tun.c:853
tun_net_init+0x409/0x540 drivers/net/tun.c:1069
register_netdevice+0x1c0/0x12a0 net/core/dev.c:9139
tun_set_iff+0x7f7/0xdc0 drivers/net/tun.c:2922
__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
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_pcp_prepare mm/page_alloc.c:1233 [inline]
free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085
free_unref_page mm/page_alloc.c:3134 [inline]
free_the_page mm/page_alloc.c:4953 [inline]
__free_pages+0xaf/0x140 mm/page_alloc.c:4961
pcpu_free_pages mm/percpu-vm.c:64 [inline]
pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
pcpu_balance_workfn+0x940/0x1450 mm/percpu.c:1865
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
Memory state around the buggy address:
ffff8881e6a87080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881e6a87100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881e6a87180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8881e6a87200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881e6a87280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 0 Comm: swapper/1 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: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881f5dc5e80
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e6a871c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffc0c0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e6a871c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d81f5000 CR4: 00000000003406a0
DR0: 0000400000000300 DR1: 0000400000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x879/0xbe0 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: 0010:default_idle+0x1f/0x30 arch/x86/kernel/process.c:573
Code: 90 90 90 90 90 90 90 90 90 90 90 e8 db b0 da fd bf 01 00 00 00 89 c6 e8 3f 95 d1 fc 0f 1f 44 00 00 0f 00 2d 73 a4 4d 00 fb f4 bc b0 da fd bf ff ff ff ff 89 c6 e9 20 95 d1 fc 41 57 41 56 53
RSP: 0018:ffff8881f5df7d78 EFLAGS: 000002d2 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff8881f5dc5e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8881f5df7e80 R08: ffffffff8231cd01 R09: ffffed103ebb8bd1
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff864c4d28
R13: ffff8881f5dc5e80 R14: 1ffff1103ebb8bd0 R15: 0000000000000001
default_idle_call kernel/sched/idle.c:94 [inline]
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x248/0x660 kernel/sched/idle.c:264
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:356
start_secondary+0x3a5/0x460 arch/x86/kernel/smpboot.c:277
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
Modules linked in:
CR2: 0000000000000000
---[ end trace 297f8592a8d098e2 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881f5dc5e80
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e6a871c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffc0c0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e6a871c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d81f5000 CR4: 00000000003406a0
DR0: 0000400000000300 DR1: 0000400000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 90 nop
a: 90 nop
b: e8 db b0 da fd call 0xfddab0eb
10: bf 01 00 00 00 mov $0x1,%edi
15: 89 c6 mov %eax,%esi
17: e8 3f 95 d1 fc call 0xfcd1955b
1c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
21: 0f 00 2d 73 a4 4d 00 verw 0x4da473(%rip) # 0x4da49b
28: fb sti
29: f4 hlt
* 2a: e8 bc b0 da fd call 0xfddab0eb <-- trapping instruction
2f: bf ff ff ff ff mov $0xffffffff,%edi
34: 89 c6 mov %eax,%esi
36: e9 20 95 d1 fc jmp 0xfcd1955b
3b: 41 57 push %r15
3d: 41 56 push %r14
3f: 53 push %rbx