==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881c296b1c8 by task syz.4.911/3453
CPU: 0 PID: 3453 Comm: syz.4.911 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:__rb_change_child include/linux/rbtree_augmented.h:176 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline]
RIP: 0010:rb_erase_augmented include/linux/rbtree_augmented.h:305 [inline]
RIP: 0010:rb_erase_augmented_cached include/linux/rbtree_augmented.h:316 [inline]
RIP: 0010:vma_interval_tree_remove+0x19b/0xa30 mm/interval_tree.c:23
Code: c1 ef 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 07 00 74 08 4c 89 e7 e8 23 2c 0a 00 48 8b 45 c0 49 39 04 24 0f 84 f8 03 00 00 e0 31 dc ff 4d 8d 7d 08 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00
RSP: 0018:ffff8881e65df768 EFLAGS: 00000213 ORIG_RAX: ffffffffffffff13
RAX: ffff8881e326c058 RBX: ffff8881d6ee4d10 RCX: 0000000000000000
RDX: ffff8881ecf66e40 RSI: ffff8881d6ee4d10 RDI: 0000000000000000
RBP: ffff8881e65df7c8 R08: dffffc0000000000 R09: ffffed103eb181c0
R10: ffffed103eb181c0 R11: 1ffff1103eb181bf R12: ffff8881d6ee4d20
R13: ffff8881d6ee4d10 R14: 0000000000000000 R15: 1ffff1103addc9a4
__remove_shared_vm_struct mm/mmap.c:149 [inline]
unlink_file_vma+0x171/0x190 mm/mmap.c:164
free_pgtables+0x139/0x280 mm/memory.c:428
exit_mmap+0x2ca/0x520 mm/mmap.c:3192
__mmput+0x92/0x2e0 kernel/fork.c:1101
mmput+0x47/0x60 kernel/fork.c:1122
exit_mm kernel/exit.c:538 [inline]
do_exit+0x99f/0x2660 kernel/exit.c:848
do_group_exit+0x13e/0x300 kernel/exit.c:984
get_signal+0xdee/0x13d0 kernel/signal.c:2738
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
syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f7fef01e969
Code: Bad RIP value.
RSP: 002b:00007f7fed6870e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007f7fef245fa8 RCX: 00007f7fef01e969
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7fef245fac
RBP: 00007f7fef245fa0 R08: 00007ffc8b38e0b0 R09: 0000000000000000
R10: 0000000000008e80 R11: 0000000000000246 R12: 00007f7fef245fac
R13: 0000000000000000 R14: 00007ffc8b29afe0 R15: 00007ffc8b29b0c8
Allocated by task 339:
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_slab_alloc+0x12/0x20 mm/kasan/common.c:537
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slub.c:2829 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
getname_flags+0xb9/0x500 fs/namei.c:141
getname fs/namei.c:212 [inline]
do_rmdir+0xcb/0x480 fs/namei.c:4055
__do_sys_unlinkat fs/namei.c:4252 [inline]
__se_sys_unlinkat fs/namei.c:4246 [inline]
__x64_sys_unlinkat+0xb6/0xe0 fs/namei.c:4246
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 339:
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+0x1c3/0x280 mm/kasan/common.c:487
kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
slab_free mm/slub.c:3080 [inline]
kmem_cache_free+0x10c/0x2c0 mm/slub.c:3096
putname fs/namei.c:262 [inline]
do_rmdir+0x392/0x480 fs/namei.c:4096
__do_sys_unlinkat fs/namei.c:4252 [inline]
__se_sys_unlinkat fs/namei.c:4246 [inline]
__x64_sys_unlinkat+0xb6/0xe0 fs/namei.c:4246
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
The buggy address belongs to the object at ffff8881c296a200
which belongs to the cache names_cache of size 4096
The buggy address is located 4040 bytes inside of
4096-byte region [ffff8881c296a200, ffff8881c296b200)
The buggy address belongs to the page:
page:ffffea00070a5a00 refcount:1 mapcount:0 mapping:ffff8881f5d01180 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d01180
raw: 0000000000000000 0000000000070007 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]
kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842
getname_flags+0xb9/0x500 fs/namei.c:141
getname fs/namei.c:212 [inline]
do_rmdir+0xcb/0x480 fs/namei.c:4055
__do_sys_unlinkat fs/namei.c:4252 [inline]
__se_sys_unlinkat fs/namei.c:4246 [inline]
__x64_sys_unlinkat+0xb6/0xe0 fs/namei.c:4246
do_syscall_64+0xcf/0x170 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+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
put_device+0x1f/0x30 drivers/base/core.c:3010
free_netdev+0x27e/0x320 net/core/dev.c:9746
tun_set_iff+0x87c/0xe00 drivers/net/tun.c:2924
__tun_chr_ioctl+0x771/0x18a0 drivers/net/tun.c:3187
tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:3470
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
Memory state around the buggy address:
ffff8881c296b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881c296b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881c296b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881c296b200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881c296b280: 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: 0 PID: 336 Comm: syz-executor 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: ffff8881f0f38000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881c296b1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb3e0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881c296b1c0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0
DR0: 0000200000000300 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+0x5c/0x250 kernel/stacktrace.c:86
Code: ed 03 43 0f b6 44 35 00 84 c0 0f 85 4b 01 00 00 45 8b 7c 24 10 49 8d 5c 24 08 48 89 d8 48 c1 e8 03 48 89 45 b8 42 0f b6 04 30 <84> c0 0f 85 49 01 00 00 48 89 5d c0 8b 1b 44 89 ff 89 de e8 cc c3
RSP: 0018:ffff8881f06c7448 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff8881f06c7568 RCX: ffff8881f0f38000
RDX: 0000000000000000 RSI: ffffffff8193fc45 RDI: ffff8881f06c7560
RBP: ffff8881f06c7498 R08: dffffc0000000000 R09: ffff8881f06c74a8
R10: ffffed103e0d8ea1 R11: 1ffff1103e0d8e95 R12: ffff8881f06c7560
R13: 1ffff1103e0d8eae R14: dffffc0000000000 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
__reset_page_owner+0x23/0x110 mm/page_owner.c:149
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+0x2a9/0x3a0 mm/page_alloc.c:3085
free_unref_page mm/page_alloc.c:3134 [inline]
free_the_page mm/page_alloc.c:4954 [inline]
__free_pages+0xaa/0x110 mm/page_alloc.c:4962
__vunmap+0x76a/0x8a0 mm/vmalloc.c:2260
__vfree mm/vmalloc.c:2308 [inline]
vfree+0x61/0x90 mm/vmalloc.c:2338
kcov_put kernel/kcov.c:396 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:495
__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
get_signal+0xdee/0x13d0 kernel/signal.c:2738
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
syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f7fef014b93
Code: Bad RIP value.
RSP: 002b:00007ffc8b29b618 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000000155 RCX: 00007f7fef014b93
RDX: 0000000040000000 RSI: 00007ffc8b29b62c RDI: 00000000ffffffff
RBP: 00007ffc8b29b62c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 66581d3cb9be97c5 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f0f38000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881c296b1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb3e0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881c296b1c0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: c1 ef 03 shr $0x3,%edi
3: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
a: fc ff df
d: 41 80 3c 07 00 cmpb $0x0,(%r15,%rax,1)
12: 74 08 je 0x1c
14: 4c 89 e7 mov %r12,%rdi
17: e8 23 2c 0a 00 call 0xa2c3f
1c: 48 8b 45 c0 mov -0x40(%rbp),%rax
20: 49 39 04 24 cmp %rax,(%r12)
24: 0f 84 f8 03 00 00 je 0x422
* 2a: e8 e0 31 dc ff call 0xffdc320f <-- trapping instruction
2f: 4d 8d 7d 08 lea 0x8(%r13),%r15
33: 4c 89 f8 mov %r15,%rax
36: 48 c1 e8 03 shr $0x3,%rax
3a: 48 rex.W
3b: b9 00 00 00 00 mov $0x0,%ecx