==================================================================
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+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881e5d831c8 by task syz.4.46/552
CPU: 0 PID: 552 Comm: syz.4.46 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack+0x1e/0x20 lib/dump_stack.c:77
dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
__kasan_report+0xef/0x120 mm/kasan/report.c:516
kasan_report+0x30/0x60 mm/kasan/common.c:653
__asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137
hlist_add_head include/linux/list.h:814 [inline]
enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
__internal_add_timer kernel/time/timer.c:554 [inline]
internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604
__mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065
mod_timer+0x1f/0x30 kernel/time/timer.c:1117
can_stat_update+0xbab/0xc40 net/can/proc.c:186
call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x81d/0xb60 kernel/time/timer.c:1817
run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
__do_softirq+0x236/0x660 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x197/0x1c0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:539 [inline]
smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
RIP: 0010:stack_trace_consume_entry+0xe2/0x250 kernel/stacktrace.c:93
Code: 00 fc ff df 0f b6 04 03 84 c0 0f 85 24 01 00 00 48 8b 45 d0 44 89 30 b0 01 e9 a8 00 00 00 e8 15 c2 0f 00 31 c0 e9 9c 00 00 00 09 c2 0f 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df
RSP: 0018:ffff8881e7546508 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff814fbc95 RBX: 1ffff1103cea8cc5 RCX: 0000000000000000
RDX: ffff8881e73f0fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881e7546558 R08: dffffc0000000000 R09: ffff8881e7546568
R10: ffffed103cea8cb9 R11: 1ffff1103cea8cad R12: ffff8881e7546620
R13: 1ffff1103cea8cc6 R14: 0000000000000000 R15: 0000000000000006
arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123
save_stack+0x97/0x560 mm/page_owner.c:122
__set_page_owner+0x39/0x1e0 mm/page_owner.c:191
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
__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]
shmem_alloc_page mm/shmem.c:1503 [inline]
shmem_alloc_and_acct_page+0x40b/0x820 mm/shmem.c:1528
shmem_getpage_gfp+0xe89/0x2370 mm/shmem.c:1852
shmem_getpage mm/shmem.c:154 [inline]
shmem_write_begin+0xce/0x1b0 mm/shmem.c:2447
generic_perform_write+0x2b8/0x500 mm/filemap.c:3450
__generic_file_write_iter+0x24b/0x480 mm/filemap.c:3579
generic_file_write_iter+0x48d/0x620 mm/filemap.c:3611
call_write_iter include/linux/fs.h:1991 [inline]
new_sync_write fs/read_write.c:483 [inline]
__vfs_write+0x480/0x5d0 fs/read_write.c:496
__kernel_write+0xea/0x320 fs/read_write.c:515
dump_emit+0x1c0/0x2c0 fs/coredump.c:838
elf_core_dump+0x3465/0x3bd0 fs/binfmt_elf.c:2352
do_coredump+0x1d8c/0x2ab0 fs/coredump.c:801
get_signal+0xdb7/0x13d0 kernel/signal.c:2732
do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
ret_from_intr+0x1c/0x1c
RIP: 0033:0x0
Code: Bad RIP value.
RSP: 002b:0000200000000148 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb5b9263fa0 RCX: 00007fb5b903c969
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000020000
RBP: 00007fb5b90beab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000200 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb5b9263fa0 R15: 00007ffc085f4588
Allocated by task 588:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
__kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543
__kmalloc+0x12a/0x2f0 mm/slub.c:3913
__kmalloc_node include/linux/slab.h:422 [inline]
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0x88/0xf0 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_init include/linux/ptr_ring.h:488 [inline]
skb_array_init include/linux/skb_array.h:182 [inline]
pfifo_fast_init+0x260/0x7a0 net/sched/sch_generic.c:784
qdisc_create_dflt+0x135/0x270 net/sched/sch_generic.c:944
mq_init+0x2df/0x660 net/sched/sch_mq.c:90
qdisc_create_dflt+0x135/0x270 net/sched/sch_generic.c:944
attach_default_qdiscs net/sched/sch_generic.c:1113 [inline]
dev_activate+0x132/0xc80 net/sched/sch_generic.c:1154
__dev_open+0x2d3/0x3f0 net/core/dev.c:1335
__dev_change_flags+0x20a/0x6a0 net/core/dev.c:7958
dev_change_flags+0x88/0x1a0 net/core/dev.c:8029
dev_ifsioc+0x110/0xa40 net/core/dev_ioctl.c:226
dev_ioctl+0x550/0xb80 net/core/dev_ioctl.c:483
sock_do_ioctl+0x235/0x330 net/socket.c:1081
sock_ioctl+0x505/0x710 net/socket.c:1198
do_vfs_ioctl+0x753/0x13f0 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+0xe1/0x120 fs/ioctl.c:747
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 0:
(stack is not available)
The buggy address belongs to the object at ffff8881e5d80000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4552 bytes to the right of
8192-byte region [ffff8881e5d80000, ffff8881e5d82000)
The buggy address belongs to the page:
page:ffffea0007976000 refcount:1 mapcount:0 mapping:ffff8881f5c0c500 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c500
raw: 0000000000000000 0000000000020002 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+0x35e/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x93/0x420 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x29e/0x420 mm/slub.c:2667
__slab_alloc+0x63/0xa0 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
__kmalloc+0x176/0x2f0 mm/slub.c:3909
__kmalloc_node include/linux/slab.h:422 [inline]
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0x88/0xf0 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_init include/linux/ptr_ring.h:488 [inline]
skb_array_init include/linux/skb_array.h:182 [inline]
pfifo_fast_init+0x112/0x7a0 net/sched/sch_generic.c:784
qdisc_create_dflt+0x135/0x270 net/sched/sch_generic.c:944
mq_init+0x2df/0x660 net/sched/sch_mq.c:90
qdisc_create_dflt+0x135/0x270 net/sched/sch_generic.c:944
attach_default_qdiscs net/sched/sch_generic.c:1113 [inline]
dev_activate+0x132/0xc80 net/sched/sch_generic.c:1154
__dev_open+0x2d3/0x3f0 net/core/dev.c:1335
__dev_change_flags+0x20a/0x6a0 net/core/dev.c:7958
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+0x7e4/0x910 mm/page_alloc.c:1438
free_the_page mm/page_alloc.c:4956 [inline]
__free_pages+0x8c/0x110 mm/page_alloc.c:4962
kfree+0x1ca/0x260 mm/slub.c:4068
kvfree+0x4c/0x50 mm/util.c:625
netdev_freemem+0x3f/0x60 net/core/dev.c:9583
netdev_release+0x7f/0xb0 net/core/net-sysfs.c:1743
device_release+0x70/0x1a0 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+0x1fe/0x2c0 lib/kobject.c:764
netdev_run_todo+0xae4/0xc70 net/core/dev.c:9488
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112
tun_detach drivers/net/tun.c:766 [inline]
tun_chr_close+0xc4/0x140 drivers/net/tun.c:3563
__fput+0x2a3/0x730 fs/file_table.c:281
____fput+0x15/0x20 fs/file_table.c:314
task_work_run+0x146/0x170 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xa43/0x2660 kernel/exit.c:861
do_group_exit+0x13e/0x300 kernel/exit.c:984
Memory state around the buggy address:
ffff8881e5d83080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881e5d83100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881e5d83180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8881e5d83200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881e5d83280: 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 1e7739067 P4D 1e7739067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 552 Comm: syz.4.46 Tainted: G B 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881e73f0fc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e5d831c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9ae0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e5d831c0
FS: 00007fb5b76a56c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e6d58000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x81d/0xb60 kernel/time/timer.c:1817
run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
__do_softirq+0x236/0x660 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x197/0x1c0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:539 [inline]
smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
RIP: 0010:stack_trace_consume_entry+0xe2/0x250 kernel/stacktrace.c:93
Code: 00 fc ff df 0f b6 04 03 84 c0 0f 85 24 01 00 00 48 8b 45 d0 44 89 30 b0 01 e9 a8 00 00 00 e8 15 c2 0f 00 31 c0 e9 9c 00 00 00 09 c2 0f 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df
RSP: 0018:ffff8881e7546508 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff814fbc95 RBX: 1ffff1103cea8cc5 RCX: 0000000000000000
RDX: ffff8881e73f0fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881e7546558 R08: dffffc0000000000 R09: ffff8881e7546568
R10: ffffed103cea8cb9 R11: 1ffff1103cea8cad R12: ffff8881e7546620
R13: 1ffff1103cea8cc6 R14: 0000000000000000 R15: 0000000000000006
arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123
save_stack+0x97/0x560 mm/page_owner.c:122
__set_page_owner+0x39/0x1e0 mm/page_owner.c:191
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
__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]
shmem_alloc_page mm/shmem.c:1503 [inline]
shmem_alloc_and_acct_page+0x40b/0x820 mm/shmem.c:1528
shmem_getpage_gfp+0xe89/0x2370 mm/shmem.c:1852
shmem_getpage mm/shmem.c:154 [inline]
shmem_write_begin+0xce/0x1b0 mm/shmem.c:2447
generic_perform_write+0x2b8/0x500 mm/filemap.c:3450
__generic_file_write_iter+0x24b/0x480 mm/filemap.c:3579
generic_file_write_iter+0x48d/0x620 mm/filemap.c:3611
call_write_iter include/linux/fs.h:1991 [inline]
new_sync_write fs/read_write.c:483 [inline]
__vfs_write+0x480/0x5d0 fs/read_write.c:496
__kernel_write+0xea/0x320 fs/read_write.c:515
dump_emit+0x1c0/0x2c0 fs/coredump.c:838
elf_core_dump+0x3465/0x3bd0 fs/binfmt_elf.c:2352
do_coredump+0x1d8c/0x2ab0 fs/coredump.c:801
get_signal+0xdb7/0x13d0 kernel/signal.c:2732
do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
ret_from_intr+0x1c/0x1c
RIP: 0033:0x0
Code: Bad RIP value.
RSP: 002b:0000200000000148 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb5b9263fa0 RCX: 00007fb5b903c969
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000020000
RBP: 00007fb5b90beab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000200 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb5b9263fa0 R15: 00007ffc085f4588
Modules linked in:
CR2: 0000000000000000
---[ end trace d2476ae619abedb5 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881e73f0fc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e5d831c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9ae0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e5d831c0
FS: 00007fb5b76a56c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e6d58000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess), 3 bytes skipped:
0: df 0f fisttps (%rdi)
2: b6 04 mov $0x4,%dh
4: 03 84 c0 0f 85 24 01 add 0x124850f(%rax,%rax,8),%eax
b: 00 00 add %al,(%rax)
d: 48 8b 45 d0 mov -0x30(%rbp),%rax
11: 44 89 30 mov %r14d,(%rax)
14: b0 01 mov $0x1,%al
16: e9 a8 00 00 00 jmp 0xc3
1b: e8 15 c2 0f 00 call 0xfc235
20: 31 c0 xor %eax,%eax
22: e9 9c 00 00 00 jmp 0xc3
* 27: e8 09 c2 0f 00 call 0xfc235 <-- trapping instruction
2c: 4c 89 e0 mov %r12,%rax
2f: 48 c1 e8 03 shr $0x3,%rax
33: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
3a: fc ff df