==================================================================
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 ffff8881e259f1c8 by task syz.5.451/1887
CPU: 1 PID: 1887 Comm: syz.5.451 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
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1086
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
get_next_corpse net/netfilter/nf_conntrack_core.c:2069 [inline]
nf_ct_iterate_cleanup+0x27c/0x310 net/netfilter/nf_conntrack_core.c:2092
nf_conntrack_cleanup_net_list+0x62/0x200 net/netfilter/nf_conntrack_core.c:2279
nf_conntrack_pernet_exit+0x146/0x160 net/netfilter/nf_conntrack_standalone.c:1153
ops_exit_list net/core/net_namespace.c:187 [inline]
setup_net+0x638/0x9b0 net/core/net_namespace.c:371
copy_net_ns+0x314/0x520 net/core/net_namespace.c:489
create_new_namespaces+0x49c/0x590 kernel/nsproxy.c:103
copy_namespaces+0x17e/0x1c0 kernel/nsproxy.c:161
copy_process+0x1194/0x2cf0 kernel/fork.c:2055
_do_fork+0x190/0x860 kernel/fork.c:2399
__do_sys_clone kernel/fork.c:2557 [inline]
__se_sys_clone kernel/fork.c:2538 [inline]
__x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f0670ee1969
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:00007f066f549fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f0671108fa0 RCX: 00007f0670ee1969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062008000
RBP: 00007f0670f63ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0671108fa0 R15: 00007ffc1d386c58
Allocated by task 692:
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
vm_area_dup kernel/fork.c:358 [inline]
dup_mmap kernel/fork.c:548 [inline]
dup_mm kernel/fork.c:1379 [inline]
copy_mm+0x752/0x1150 kernel/fork.c:1435
copy_process+0x1163/0x2cf0 kernel/fork.c:2052
_do_fork+0x190/0x860 kernel/fork.c:2399
__do_sys_clone kernel/fork.c:2557 [inline]
__se_sys_clone kernel/fork.c:2538 [inline]
__x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 2080:
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
vm_area_free+0x1c/0x20 kernel/fork.c:369
remove_vma mm/mmap.c:182 [inline]
exit_mmap+0x41b/0x520 mm/mmap.c:3202
__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+0x61/0x80 arch/x86/entry/common.c:274
ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:346
The buggy address belongs to the object at ffff8881e259f128
which belongs to the cache vm_area_struct of size 232
The buggy address is located 160 bytes inside of
232-byte region [ffff8881e259f128, ffff8881e259f210)
The buggy address belongs to the page:
page:ffffea00078967c0 refcount:1 mapcount:0 mapping:ffff8881f5cf6000 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f5cf6000
raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY)
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
vm_area_dup+0x24/0xa0 kernel/fork.c:358
__split_vma+0xb5/0x430 mm/mmap.c:2705
split_vma+0x7c/0xd0 mm/mmap.c:2765
mprotect_fixup+0x5bb/0x810 mm/mprotect.c:448
do_mprotect_pkey+0x5f6/0x7e0 mm/mprotect.c:588
__do_sys_mprotect mm/mprotect.c:613 [inline]
__se_sys_mprotect mm/mprotect.c:610 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:610
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_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
kvfree+0x3d/0x50 mm/util.c:623
bpf_map_area_free+0x15/0x20 kernel/bpf/syscall.c:162
reuseport_array_free+0x181/0x1b0 kernel/bpf/reuseport_array.c:147
map_create+0x433/0x980 kernel/bpf/syscall.c:639
__do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
__se_sys_bpf+0x2dc/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
Memory state around the buggy address:
ffff8881e259f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
ffff8881e259f100: fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e259f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881e259f200: fb fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb
ffff8881e259f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
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: 1887 Comm: syz.5.451 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:__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+0x74b/0xb60 kernel/time/timer.c:1817
Code: 89 ef e8 88 d8 3c 00 4d 89 65 00 4d 85 e4 74 2e e8 aa dd 0e 00 49 83 c4 08 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 57 d8 3c 00 4d 89 2c 24 eb 05 e8 7c
RSP: 0018:ffff8881f6f09d40 EFLAGS: 00010002
RAX: 0000000040000001 RBX: 1ffff1103c4b3e39 RCX: dffffc0000000000
RDX: 0000000000000102 RSI: 0000000000000008 RDI: ffff8881e259f1c8
RBP: ffff8881f6f09eb8 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 0000000200000008
R13: ffff8881f6f09e00 R14: ffff8881e259f1c8 R15: 1ffff1103c4b3e38
FS: 00007f066f54a6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564084879038 CR3: 00000001ead4e000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x56/0x80 kernel/locking/spinlock.c:191
Code: b0 2d cb 85 e8 ab 7f 62 fd 4c 89 f7 48 83 3d 40 34 a0 01 00 74 34 e8 0d 38 1d fd 66 90 48 89 5d e8 ff 75 e8 9d bf 01 00 00 00 e5 7a 16 fd 65 8b 05 fa 93 d7 7b 85 c0 74 09 48 83 c4 08 5b 41
RSP: 0018:ffff8881e3f37758 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000a06 RCX: dffffc0000000000
RDX: ffffc90001547000 RSI: 0000000000000a06 RDI: 0000000000000001
RBP: ffff8881e3f37770 R08: dffffc0000000000 R09: ffffed103ba142ae
R10: ffffed103ba142ae R11: 1ffff1103ba142ad R12: 1ffff1103c7e6ef4
R13: dffffc0000000000 R14: ffff8881f5cc3600 R15: 0000000000000000
spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
ida_free+0x2b4/0x300 lib/idr.c:519
proc_free_inum fs/proc/generic.c:224 [inline]
pde_put+0x7b/0x1a0 fs/proc/generic.c:669
remove_proc_entry+0x2fa/0x410 fs/proc/generic.c:708
exp_proc_remove net/netfilter/nf_conntrack_expect.c:681 [inline]
nf_conntrack_expect_pernet_fini+0x42/0x50 net/netfilter/nf_conntrack_expect.c:695
nf_conntrack_cleanup_net_list+0x166/0x200 net/netfilter/nf_conntrack_core.c:2291
nf_conntrack_pernet_exit+0x146/0x160 net/netfilter/nf_conntrack_standalone.c:1153
ops_exit_list net/core/net_namespace.c:187 [inline]
setup_net+0x638/0x9b0 net/core/net_namespace.c:371
copy_net_ns+0x314/0x520 net/core/net_namespace.c:489
create_new_namespaces+0x49c/0x590 kernel/nsproxy.c:103
copy_namespaces+0x17e/0x1c0 kernel/nsproxy.c:161
copy_process+0x1194/0x2cf0 kernel/fork.c:2055
_do_fork+0x190/0x860 kernel/fork.c:2399
__do_sys_clone kernel/fork.c:2557 [inline]
__se_sys_clone kernel/fork.c:2538 [inline]
__x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f0670ee1969
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:00007f066f549fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f0671108fa0 RCX: 00007f0670ee1969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062008000
RBP: 00007f0670f63ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0671108fa0 R15: 00007ffc1d386c58
Modules linked in:
---[ end trace f8d06eaebfb05120 ]---
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+0x74b/0xb60 kernel/time/timer.c:1817
Code: 89 ef e8 88 d8 3c 00 4d 89 65 00 4d 85 e4 74 2e e8 aa dd 0e 00 49 83 c4 08 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 57 d8 3c 00 4d 89 2c 24 eb 05 e8 7c
RSP: 0018:ffff8881f6f09d40 EFLAGS: 00010002
RAX: 0000000040000001 RBX: 1ffff1103c4b3e39 RCX: dffffc0000000000
RDX: 0000000000000102 RSI: 0000000000000008 RDI: ffff8881e259f1c8
RBP: ffff8881f6f09eb8 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 0000000200000008
R13: ffff8881f6f09e00 R14: ffff8881e259f1c8 R15: 1ffff1103c4b3e38
FS: 00007f066f54a6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564084879038 CR3: 00000001ead4e000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: 89 ef mov %ebp,%edi
2: e8 88 d8 3c 00 call 0x3cd88f
7: 4d 89 65 00 mov %r12,0x0(%r13)
b: 4d 85 e4 test %r12,%r12
e: 74 2e je 0x3e
10: e8 aa dd 0e 00 call 0xeddbf
15: 49 83 c4 08 add $0x8,%r12
19: 4c 89 e0 mov %r12,%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 e7 mov %r12,%rdi
33: e8 57 d8 3c 00 call 0x3cd88f
38: 4d 89 2c 24 mov %r13,(%r12)
3c: eb 05 jmp 0x43
3e: e8 .byte 0xe8
3f: 7c .byte 0x7c