==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline]
BUG: KASAN: use-after-free in __run_timers+0x759/0xb60 kernel/time/timer.c:1817
Write of size 8 at addr ffff8881e4dc71c8 by task syz.4.527/2362
CPU: 1 PID: 2362 Comm: syz.4.527 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_del include/linux/list.h:791 [inline]
detach_timer kernel/time/timer.c:824 [inline]
expire_timers kernel/time/timer.c:1482 [inline]
__run_timers+0x759/0xb60 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:bytes_is_nonzero mm/kasan/generic.c:90 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:181 [inline]
RIP: 0010:check_memory_region+0x60/0x280 mm/kasan/generic.c:191
Code: c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 <4d> 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 0f 85 c2
RSP: 0018:ffff8881e43e7048 EFLAGS: 00000283 ORIG_RAX: ffffffffffffff13
RAX: ffffffff817a1a01 RBX: 1ffffd4000e7efa6 RCX: ffffffff817a1a84
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea00073f7d34
RBP: ffff8881e43e7060 R08: dffffc0000000000 R09: fffff94000e7efa6
R10: fffff94000e7efa7 R11: 1ffffd4000e7efa6 R12: ffffea00073f7d00
R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000001
__kasan_check_read+0x11/0x20 mm/kasan/common.c:93
atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline]
atomic_add_unless include/linux/atomic-fallback.h:1111 [inline]
page_ref_add_unless include/linux/page_ref.h:157 [inline]
__page_cache_add_speculative include/linux/pagemap.h:189 [inline]
page_cache_get_speculative include/linux/pagemap.h:205 [inline]
filemap_map_pages+0x264/0xb00 mm/filemap.c:2783
do_fault_around mm/memory.c:3658 [inline]
do_read_fault mm/memory.c:3693 [inline]
do_fault mm/memory.c:3828 [inline]
handle_pte_fault mm/memory.c:4059 [inline]
__handle_mm_fault mm/memory.c:4183 [inline]
handle_mm_fault+0x1ede/0x3930 mm/memory.c:4220
faultin_page mm/gup.c:654 [inline]
__get_user_pages+0xc50/0x15d0 mm/gup.c:874
get_dump_page+0xd1/0x140 mm/gup.c:1363
elf_core_dump+0x3438/0x3bd0 fs/binfmt_elf.c:2349
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: 0033:0x9ea3
Code: Bad RIP value.
RSP: 002b:0000200000000278 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb80b6a7080 RCX: 00007fb80b47f969
RDX: 0000200000000280 RSI: 0000200000000270 RDI: 0000000000108000
RBP: 00007fb80b501ab1 R08: 0000200000000300 R09: 0000200000000300
R10: 00002000000002c0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb80b6a7080 R15: 00007fff1b6604d8
Allocated by task 2367:
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]
__kmalloc_track_caller+0x10d/0x2d0 mm/slub.c:4449
__kmalloc_reserve net/core/skbuff.c:142 [inline]
pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653
skb_ensure_writable+0x2e7/0x460 net/core/skbuff.c:5569
__bpf_try_make_writable net/core/filter.c:1635 [inline]
bpf_try_make_writable net/core/filter.c:1641 [inline]
bpf_try_make_head_writable net/core/filter.c:1649 [inline]
____bpf_clone_redirect net/core/filter.c:2145 [inline]
bpf_clone_redirect+0x10b/0x380 net/core/filter.c:2123
bpf_prog_ea5dd1b4147210ac+0x9e7/0x1000
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
Freed by task 2367:
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]
kfree+0xbe/0x260 mm/slub.c:4071
skb_free_head net/core/skbuff.c:601 [inline]
skb_release_data+0x4ea/0x610 net/core/skbuff.c:621
skb_release_all net/core/skbuff.c:675 [inline]
__kfree_skb net/core/skbuff.c:689 [inline]
kfree_skb+0xbc/0x3a0 net/core/skbuff.c:708
tun_net_xmit+0x947/0xfa0 drivers/net/tun.c:1199
__netdev_start_xmit include/linux/netdevice.h:4544 [inline]
netdev_start_xmit include/linux/netdevice.h:4558 [inline]
xmit_one net/core/dev.c:3221 [inline]
dev_hard_start_xmit+0x1ef/0x6f0 net/core/dev.c:3237
sch_direct_xmit+0x24b/0x8b0 net/sched/sch_generic.c:336
qdisc_restart net/sched/sch_generic.c:401 [inline]
__qdisc_run+0x954/0x1370 net/sched/sch_generic.c:409
qdisc_run+0x10a/0x300 include/net/pkt_sched.h:122
__dev_xmit_skb net/core/dev.c:3432 [inline]
__dev_queue_xmit+0x9dd/0x2400 net/core/dev.c:3787
dev_queue_xmit+0x17/0x20 net/core/dev.c:3854
__bpf_tx_skb net/core/filter.c:2063 [inline]
__bpf_redirect_common net/core/filter.c:2111 [inline]
__bpf_redirect+0x9f9/0xe30 net/core/filter.c:2118
____bpf_clone_redirect net/core/filter.c:2151 [inline]
bpf_clone_redirect+0x242/0x380 net/core/filter.c:2123
bpf_prog_ea5dd1b4147210ac+0x9e7/0x1000
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
The buggy address belongs to the object at ffff8881e4dc7000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 456 bytes inside of
512-byte region [ffff8881e4dc7000, ffff8881e4dc7200)
The buggy address belongs to the page:
page:ffffea0007937100 refcount:1 mapcount:0 mapping:ffff8881f5c02500 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c02500
raw: 0000000000000000 0000000000100010 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 0x1d2a20(GFP_ATOMIC|__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_track_caller+0x17c/0x2d0 mm/slub.c:4449
__kmalloc_reserve net/core/skbuff.c:142 [inline]
pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653
skb_ensure_writable+0x2e7/0x460 net/core/skbuff.c:5569
__bpf_try_make_writable net/core/filter.c:1635 [inline]
bpf_try_make_writable net/core/filter.c:1641 [inline]
bpf_try_make_head_writable net/core/filter.c:1649 [inline]
____bpf_clone_redirect net/core/filter.c:2145 [inline]
bpf_clone_redirect+0x10b/0x380 net/core/filter.c:2123
bpf_prog_ea5dd1b4147210ac+0x9e7/0x1000
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
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_sys_exit kernel/exit.c:953 [inline]
__se_sys_exit kernel/exit.c:951 [inline]
__ia32_sys_exit+0x0/0x40 kernel/exit.c:951
Memory state around the buggy address:
ffff8881e4dc7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881e4dc7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e4dc7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881e4dc7200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881e4dc7280: 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 1c9b08067 P4D 1c9b08067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 2362 Comm: syz.4.527 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:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881e88cee40
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e4dc71c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 0000000100002718
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e4dc71c0
FS: 00007fb809ac76c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb1de000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 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:bytes_is_nonzero mm/kasan/generic.c:90 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:181 [inline]
RIP: 0010:check_memory_region+0x60/0x280 mm/kasan/generic.c:191
Code: c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 <4d> 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 0f 85 c2
RSP: 0018:ffff8881e43e7048 EFLAGS: 00000283 ORIG_RAX: ffffffffffffff13
RAX: ffffffff817a1a01 RBX: 1ffffd4000e7efa6 RCX: ffffffff817a1a84
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea00073f7d34
RBP: ffff8881e43e7060 R08: dffffc0000000000 R09: fffff94000e7efa6
R10: fffff94000e7efa7 R11: 1ffffd4000e7efa6 R12: ffffea00073f7d00
R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000001
__kasan_check_read+0x11/0x20 mm/kasan/common.c:93
atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline]
atomic_add_unless include/linux/atomic-fallback.h:1111 [inline]
page_ref_add_unless include/linux/page_ref.h:157 [inline]
__page_cache_add_speculative include/linux/pagemap.h:189 [inline]
page_cache_get_speculative include/linux/pagemap.h:205 [inline]
filemap_map_pages+0x264/0xb00 mm/filemap.c:2783
do_fault_around mm/memory.c:3658 [inline]
do_read_fault mm/memory.c:3693 [inline]
do_fault mm/memory.c:3828 [inline]
handle_pte_fault mm/memory.c:4059 [inline]
__handle_mm_fault mm/memory.c:4183 [inline]
handle_mm_fault+0x1ede/0x3930 mm/memory.c:4220
faultin_page mm/gup.c:654 [inline]
__get_user_pages+0xc50/0x15d0 mm/gup.c:874
get_dump_page+0xd1/0x140 mm/gup.c:1363
elf_core_dump+0x3438/0x3bd0 fs/binfmt_elf.c:2349
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: 0033:0x9ea3
Code: Bad RIP value.
RSP: 002b:0000200000000278 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb80b6a7080 RCX: 00007fb80b47f969
RDX: 0000200000000280 RSI: 0000200000000270 RDI: 0000000000108000
RBP: 00007fb80b501ab1 R08: 0000200000000300 R09: 0000200000000300
R10: 00002000000002c0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb80b6a7080 R15: 00007fff1b6604d8
Modules linked in:
CR2: 0000000000000000
---[ end trace 4bca74aee38d1e27 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881e88cee40
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e4dc71c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 0000000100002718
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e4dc71c0
FS: 00007fb809ac76c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb1de000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: c1 eb 03 shr $0x3,%ebx
3: 49 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%r8
a: fc ff df
d: 4f 8d 0c 03 lea (%r11,%r8,1),%r9
11: 48 8d 5c 37 ff lea -0x1(%rdi,%rsi,1),%rbx
16: 48 c1 eb 03 shr $0x3,%rbx
1a: 4e 8d 14 3b lea (%rbx,%r15,1),%r10
1e: 4d 89 d6 mov %r10,%r14
21: 4d 29 ce sub %r9,%r14
24: 49 83 fe 10 cmp $0x10,%r14
28: 7f 26 jg 0x50
* 2a: 4d 85 f6 test %r14,%r14 <-- trapping instruction
2d: 0f 84 39 01 00 00 je 0x16c
33: 48 f7 d3 not %rbx
36: 4c 01 db add %r11,%rbx
39: 41 80 39 00 cmpb $0x0,(%r9)
3d: 0f .byte 0xf
3e: 85 c2 test %eax,%edx