==================================================================
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 ffff8881d4eb71c8 by task syz.0.371/1711
CPU: 0 PID: 1711 Comm: syz.0.371 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:
<IRQ>
__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
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1086
</IRQ>
do_softirq+0xf9/0x140 kernel/softirq.c:337
__local_bh_enable_ip+0x70/0x80 kernel/softirq.c:189
local_bh_enable+0x1f/0x30 include/linux/bottom_half.h:32
rcu_read_unlock_bh include/linux/rcupdate.h:739 [inline]
__dev_queue_xmit+0x136e/0x2400 net/core/dev.c:3848
dev_queue_xmit+0x17/0x20 net/core/dev.c:3854
__bpf_tx_skb net/core/filter.c:2063 [inline]
__bpf_redirect_no_mac net/core/filter.c:2097 [inline]
__bpf_redirect+0x699/0xe30 net/core/filter.c:2120
____bpf_clone_redirect net/core/filter.c:2151 [inline]
bpf_clone_redirect+0x242/0x380 net/core/filter.c:2123
bpf_prog_2658eab614f371a8+0x5c5/0x1000
bpf_call_func include/linux/filter.h:627 [inline]
bpf_test_run+0x1ea/0x5d0 net/bpf/test_run.c:44
bpf_prog_test_run_skb+0x721/0xdc0 net/bpf/test_run.c:311
bpf_prog_test_run+0x21a/0x2a0 kernel/bpf/syscall.c:2124
__do_sys_bpf kernel/bpf/syscall.c:2909 [inline]
__se_sys_bpf+0x49a/0x570 kernel/bpf/syscall.c:2849
__x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fcb54afe969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcb53167038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fcb54d25fa0 RCX: 00007fcb54afe969
RDX: 0000000000000050 RSI: 0000200000001300 RDI: 000000000000000a
RBP: 00007fcb54b80ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcb54d25fa0 R15: 00007fff9e21ee48
Allocated by task 1626:
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
shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719
alloc_inode fs/inode.c:231 [inline]
new_inode_pseudo+0x62/0x210 fs/inode.c:966
new_inode+0x28/0x1e0 fs/inode.c:995
shmem_get_inode+0x107/0x630 mm/shmem.c:2252
shmem_symlink+0x9e/0x4d0 mm/shmem.c:3068
vfs_symlink+0x337/0x4c0 fs/namei.c:4276
do_symlinkat+0x103/0x3b0 fs/namei.c:4303
__do_sys_symlinkat fs/namei.c:4317 [inline]
__se_sys_symlinkat fs/namei.c:4314 [inline]
__x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4314
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 1652:
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
shmem_free_in_core_inode+0x90/0xb0 mm/shmem.c:3729
i_callback+0x4c/0x70 fs/inode.c:220
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x446/0x980 kernel/rcu/tree.c:2167
rcu_core+0x4bd/0xbd0 kernel/rcu/tree.c:2387
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2396
__do_softirq+0x236/0x660 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881d4eb7090
which belongs to the cache shmem_inode_cache of size 760
The buggy address is located 312 bytes inside of
760-byte region [ffff8881d4eb7090, ffff8881d4eb7388)
The buggy address belongs to the page:
page:ffffea000753ad00 refcount:1 mapcount:0 mapping:ffff8881f5d02000 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d02000
raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, 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
shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719
alloc_inode fs/inode.c:231 [inline]
new_inode_pseudo+0x62/0x210 fs/inode.c:966
new_inode+0x28/0x1e0 fs/inode.c:995
shmem_get_inode+0x107/0x630 mm/shmem.c:2252
shmem_symlink+0x9e/0x4d0 mm/shmem.c:3068
vfs_symlink+0x337/0x4c0 fs/namei.c:4276
do_symlinkat+0x103/0x3b0 fs/namei.c:4303
__do_sys_symlinkat fs/namei.c:4317 [inline]
__se_sys_symlinkat fs/namei.c:4314 [inline]
__x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4314
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
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x195/0x1b0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
Memory state around the buggy address:
ffff8881d4eb7080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d4eb7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d4eb7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881d4eb7200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d4eb7280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
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: 329 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: 00010006
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f31dcec0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d4eb71c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa058
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4eb71c0
FS: 000055556a005500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001dea33000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1488 [inline]
__run_timers+0x84b/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
</IRQ>
RIP: 0010:__hrtimer_init+0x13c/0x280 kernel/time/hrtimer.c:1441
Code: f7 00 00 74 25 e8 f4 a2 0e 00 49 bd 00 00 00 00 00 fc ff df 48 c7 c7 40 c8 88 84 44 89 fe e8 3b 2c d6 02 0f 0b 45 31 ff eb 17 <46> 8b 3c a5 a0 c7 88 84 e8 c7 a2 0e 00 49 bd 00 00 00 00 00 fc ff
RSP: 0018:ffff8881f0dd7c38 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff8150dbde RBX: ffff8881f0dd7d20 RCX: 0000000000000000
RDX: ffff8881f31dcec0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881f0dd7c68 R08: dffffc0000000000 R09: ffff8881f0dd7d20
R10: ffffed103e1bafad R11: 1ffff1103e1bafa4 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
__hrtimer_init_sleeper kernel/time/hrtimer.c:1894 [inline]
hrtimer_init_sleeper+0x41/0x1f0 kernel/time/hrtimer.c:1909
hrtimer_init_sleeper_on_stack include/linux/hrtimer.h:398 [inline]
hrtimer_nanosleep+0x14e/0x440 kernel/time/hrtimer.c:1993
common_nsleep+0x2c/0x40 kernel/time/posix-timers.c:1203
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1231 [inline]
__se_sys_clock_nanosleep+0x305/0x3a0 kernel/time/posix-timers.c:1208
__x64_sys_clock_nanosleep+0x9b/0xb0 kernel/time/posix-timers.c:1208
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fc8bebb31e3
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 5e 33 1c 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffd9020e2c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc8bebb31e3
RDX: 00007ffd9020e2e0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007ffd903bc080 R09: 00007ffd903bc0b0
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd9020e730
R13: 0000000000000004 R14: 00007ffd9020e31c R15: 00007ffd9020e3b0
Modules linked in:
CR2: 0000000000000000
---[ end trace eea4dd7222bc23fd ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010006
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f31dcec0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d4eb71c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa058
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4eb71c0
FS: 000055556a005500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001dea33000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 00 00 add %al,(%rax)
2: 74 25 je 0x29
4: e8 f4 a2 0e 00 call 0xea2fd
9: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
10: fc ff df
13: 48 c7 c7 40 c8 88 84 mov $0xffffffff8488c840,%rdi
1a: 44 89 fe mov %r15d,%esi
1d: e8 3b 2c d6 02 call 0x2d62c5d
22: 0f 0b ud2
24: 45 31 ff xor %r15d,%r15d
27: eb 17 jmp 0x40
* 29: 46 8b 3c a5 a0 c7 88 mov -0x7b773860(,%r12,4),%r15d <-- trapping instruction
30: 84
31: e8 c7 a2 0e 00 call 0xea2fd
36: 49 rex.WB
37: bd 00 00 00 00 mov $0x0,%ebp
3c: 00 fc add %bh,%ah
3e: ff .byte 0xff