==================================================================
BUG: KASAN: use-after-free in strlen+0x57/0x70 lib/string.c:502
Read of size 1 at addr ffff88810b566910 by task syz.0.819/15038
CPU: 1 PID: 15038 Comm: syz.0.819 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x71/0x200 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:420
kasan_report+0x122/0x150 mm/kasan/report.c:524
__asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348
strlen+0x57/0x70 lib/string.c:502
__fortify_strlen include/linux/fortify-string.h:196 [inline]
trace_event_get_offsets_irq_handler_entry include/trace/events/irq.h:61 [inline]
do_trace_event_raw_event_irq_handler_entry include/trace/events/irq.h:53 [inline]
trace_event_raw_event_irq_handler_entry+0x107/0x280 include/trace/events/irq.h:53
trace_irq_handler_entry include/trace/events/irq.h:53 [inline]
__handle_irq_event_percpu+0x4bb/0x680 kernel/irq/handle.c:157
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x8e/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x2ae/0xd50 kernel/irq/chip.c:834
generic_handle_irq_desc include/linux/irqdesc.h:160 [inline]
handle_irq arch/x86/kernel/irq.c:233 [inline]
__common_interrupt+0xa9/0x1d0 arch/x86/kernel/irq.c:252
common_interrupt+0x5f/0xe0 arch/x86/kernel/irq.c:242
asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:handle_softirqs+0x144/0x600 kernel/softirq.c:630
Code: 85 e8 40 6e b7 03 65 66 89 1d 38 13 c0 7e 48 c7 c7 c0 0d 69 85 e8 2c 6e b7 03 65 44 89 25 3c 0f bf 7e fb 49 c7 c5 c0 a0 00 87 <44> 89 65 ac b8 ff ff ff ff 0f bc 45 ac 89 c3 ff c3 0f 84 a2 02 00
RSP: 0018:ffffc900001b0f30 EFLAGS: 00000286
RAX: 0000000000000001 RBX: 0000000000000008 RCX: 36bd428d997d4800
RDX: 1ffffffff0f6e808 RSI: ffffffff85690dc0 RDI: ffffffff85ca7160
RBP: ffffc900001b0fc0 R08: ffffffff87b74048 R09: ffffffff87b74058
R10: ffffffff87b74043 R11: 1ffffffff0f6e808 R12: 0000000000000000
R13: ffffffff8700a0c0 R14: 0000000000000008 R15: ffff888139269440
__do_softirq kernel/softirq.c:680 [inline]
invoke_softirq kernel/softirq.c:497 [inline]
__irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x55/0x80 kernel/locking/spinlock.c:194
Code: c0 db 0d 87 e8 ec 76 b5 fc 4c 89 f7 48 83 3d b1 58 0c 02 00 74 30 e8 9e 0d 00 00 90 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b6 13 4b fc 65 8b 05 97 ea 00 7b 85 c0 74 05 5b 41 5e 5d c3 e8
RSP: 0018:ffffc90002ef7370 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000a02 RCX: dffffc0000000000
RDX: ffffc90001279000 RSI: 0000000000000a02 RDI: 0000000000000001
RBP: ffffc90002ef7380 R08: ffff8881001744b7 R09: 1ffff1102002e896
R10: dffffc0000000000 R11: ffffed102002e897 R12: ffffffff878e9cc0
R13: 0000000000000000 R14: ffff8881f6f3c968 R15: 0000000000000001
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
free_pcppages_bulk+0x84f/0x880 mm/page_alloc.c:1737
free_unref_page_commit+0x398/0x6d0 mm/page_alloc.c:3704
free_unref_page_list+0x611/0x8d0 mm/page_alloc.c:3832
release_pages+0xc7e/0xce0 mm/swap.c:1053
__pagevec_release+0x71/0xe0 mm/swap.c:1073
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x564/0x14e0 mm/shmem.c:951
shmem_truncate_range mm/shmem.c:1067 [inline]
shmem_evict_inode+0x21f/0x9c0 mm/shmem.c:1176
evict+0x4c4/0x8c0 fs/inode.c:709
iput_final fs/inode.c:1845 [inline]
iput+0x633/0x690 fs/inode.c:1871
dentry_unlink_inode+0x346/0x3f0 fs/dcache.c:405
__dentry_kill+0x46c/0x680 fs/dcache.c:611
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
__fput+0x5c0/0x8f0 fs/file_table.c:328
____fput+0x15/0x20 fs/file_table.c:348
task_work_run+0x1e1/0x250 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1b3195e9ce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f1b3295bda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f1b3295c6c0 RCX: 00007f1b3195e9ce
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00007f1b3295bee0 R14: 00007f1b3295bea0 R15: 00007f1b27ff8000
Allocated by task 1:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:380 [inline]
__kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
kasan_kmalloc include/linux/kasan.h:212 [inline]
__do_kmalloc_node mm/slab_common.c:938 [inline]
__kmalloc_node_track_caller+0xb1/0x1e0 mm/slab_common.c:958
kvasprintf+0xe8/0x1a0 lib/kasprintf.c:25
kasprintf+0xdf/0x130 lib/kasprintf.c:59
uart_add_one_port+0x38b/0x1cf0 drivers/tty/serial/serial_core.c:3117
serial8250_register_8250_port+0x1368/0x1b70 drivers/tty/serial/8250/8250_core.c:1092
serial_pnp_probe+0x51e/0x710 drivers/tty/serial/8250/8250_pnp.c:478
pnp_device_probe+0x312/0x4d0 drivers/pnp/driver.c:111
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2d7/0x9a0 drivers/base/dd.c:639
__driver_probe_device+0x193/0x270 drivers/base/dd.c:808
driver_probe_device+0x54/0x3e0 drivers/base/dd.c:838
__driver_attach+0x41a/0x5d0 drivers/base/dd.c:1224
bus_for_each_dev+0x18c/0x200 drivers/base/bus.c:303
driver_attach+0x42/0x50 drivers/base/dd.c:1241
bus_add_driver+0x322/0x560 drivers/base/bus.c:620
driver_register+0x335/0x440 drivers/base/driver.c:246
pnp_register_driver+0x7d/0x90 drivers/pnp/driver.c:273
serial8250_pnp_init+0x15/0x20 drivers/tty/serial/8250/8250_pnp.c:533
serial8250_init+0xa0/0x16e drivers/tty/serial/8250/8250_core.c:1191
do_one_initcall+0x1d6/0x580 init/main.c:1433
do_initcall_level+0x174/0x2df init/main.c:1506
do_initcalls+0x50/0x92 init/main.c:1522
do_basic_setup+0x92/0x99 init/main.c:1541
kernel_init_freeable+0x2d1/0x42d init/main.c:1761
kernel_init+0x1d/0x1c0 init/main.c:1649
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Freed by task 15083:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1750 [inline]
slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
slab_free mm/slub.c:3712 [inline]
__kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
kfree+0x6f/0xf0 mm/slab_common.c:990
uart_remove_one_port+0x36a/0x720 drivers/tty/serial/serial_core.c:3235
serial8250_unregister_port+0xad/0x250 drivers/tty/serial/8250/8250_core.c:1154
serial_pnp_remove+0x6b/0x90 drivers/tty/serial/8250/8250_pnp.c:496
pnp_device_remove+0x84/0x260 drivers/pnp/driver.c:133
device_remove drivers/base/dd.c:548 [inline]
__device_release_driver drivers/base/dd.c:1283 [inline]
device_release_driver_internal+0x486/0x7e0 drivers/base/dd.c:1309
device_driver_detach+0x3b/0x40 drivers/base/dd.c:1345
unbind_store+0x2e5/0x300 drivers/base/bus.c:193
drv_attr_store+0x88/0xb0 drivers/base/bus.c:77
sysfs_kf_write+0x137/0x150 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x307/0x470 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2282 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x5ef/0xd00 fs/read_write.c:584
ksys_write+0x14a/0x260 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x7b/0x90 fs/read_write.c:646
x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff88810b566910
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
8-byte region [ffff88810b566910, ffff88810b566918)
The buggy address belongs to the physical page:
page:ffffea00042d5980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b566
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000001 ffff888100042300
raw: 0000000000000000 0000000000660066 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 2510193330, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673
prep_new_page+0x1c/0x110 mm/page_alloc.c:2680
get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587
__alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3e0 mm/slub.c:2020
___slab_alloc+0x70f/0xb70 mm/slub.c:3177
__slab_alloc+0x5e/0xa0 mm/slub.c:3263
slab_alloc_node mm/slub.c:3348 [inline]
__kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423
__do_kmalloc_node mm/slab_common.c:937 [inline]
__kmalloc+0xa4/0x1e0 mm/slab_common.c:951
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
acpi_os_allocate_zeroed include/acpi/platform/aclinuxex.h:57 [inline]
acpi_ns_internalize_name+0x2cd/0x3b0 drivers/acpi/acpica/nsutils.c:331
acpi_ns_get_node_unlocked drivers/acpi/acpica/nsutils.c:666 [inline]
acpi_ns_get_node+0x1a7/0x360 drivers/acpi/acpica/nsutils.c:726
acpi_ns_evaluate+0x35d/0xa20 drivers/acpi/acpica/nseval.c:62
acpi_evaluate_object+0x588/0xa60 drivers/acpi/acpica/nsxfeval.c:354
acpi_processor_get_throttling_control drivers/acpi/processor_throttling.c:410 [inline]
acpi_processor_get_throttling_info+0xf5/0x1c80 drivers/acpi/processor_throttling.c:1176
acpi_pss_perf_init drivers/acpi/processor_driver.c:146 [inline]
__acpi_processor_start+0xf7/0x240 drivers/acpi/processor_driver.c:174
page_owner free stack trace missing
Memory state around the buggy address:
ffff88810b566800: fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 04 fc
ffff88810b566880: fc fc fc 05 fc fc fc fc 05 fc fc fc fc 06 fc fc
>ffff88810b566900: fc fc fa fc fc fc fc 05 fc fc fc fc 00 fc fc fc
^
ffff88810b566980: fc 05 fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc
ffff88810b566a00: 05 fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 05
==================================================================
----------------
Code disassembly (best guess):
0: 85 e8 test %ebp,%eax
2: 40 6e rex outsb %ds:(%rsi),(%dx)
4: b7 03 mov $0x3,%bh
6: 65 66 89 1d 38 13 c0 mov %bx,%gs:0x7ec01338(%rip) # 0x7ec01346
d: 7e
e: 48 c7 c7 c0 0d 69 85 mov $0xffffffff85690dc0,%rdi
15: e8 2c 6e b7 03 call 0x3b76e46
1a: 65 44 89 25 3c 0f bf mov %r12d,%gs:0x7ebf0f3c(%rip) # 0x7ebf0f5e
21: 7e
22: fb sti
23: 49 c7 c5 c0 a0 00 87 mov $0xffffffff8700a0c0,%r13
* 2a: 44 89 65 ac mov %r12d,-0x54(%rbp) <-- trapping instruction
2e: b8 ff ff ff ff mov $0xffffffff,%eax
33: 0f bc 45 ac bsf -0x54(%rbp),%eax
37: 89 c3 mov %eax,%ebx
39: ff c3 inc %ebx
3b: 0f .byte 0xf
3c: 84 .byte 0x84
3d: a2 .byte 0xa2
3e: 02 00 add (%rax),%al