================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] BUG: KASAN: slab-use-after-free in string+0x216/0x2d0 lib/vsprintf.c:730 Read of size 1 at addr ffff888021367b80 by task syz.1.381/7391 CPU: 0 UID: 0 PID: 7391 Comm: syz.1.381 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 string_nocheck lib/vsprintf.c:648 [inline] string+0x216/0x2d0 lib/vsprintf.c:730 vsnprintf+0x74a/0xef0 lib/vsprintf.c:2949 vprintk_store+0x3d9/0xdc0 kernel/printk/printk.c:2307 vprintk_emit+0x192/0x560 kernel/printk/printk.c:2455 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __setup_irq+0x12a1/0x20a0 kernel/irq/manage.c:1821 request_threaded_irq+0x2c1/0x3a0 kernel/irq/manage.c:2184 request_irq include/linux/interrupt.h:176 [inline] pcl812_attach+0x254/0x22b0 drivers/comedi/drivers/pcl812.c:1174 comedi_device_attach+0x535/0x730 drivers/comedi/drivers.c:1101 do_devconfig_ioctl drivers/comedi/comedi_fops.c:930 [inline] comedi_unlocked_ioctl+0x8f4/0x1af0 drivers/comedi/comedi_fops.c:2302 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe9bd4be199 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe9bb716028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe9bd745fa0 RCX: 00007fe9bd4be199 RDX: 0000200000000240 RSI: 0000000040946400 RDI: 0000000000000004 RBP: 00007fe9bd5550b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe9bd746038 R14: 00007fe9bd745fa0 R15: 00007ffe4468a8b8 Allocated by task 6581: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_node_track_caller_noprof+0x56e/0x7b0 mm/slub.c:5545 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:715 [inline] xattr_dupval security/smack/smack_lsm.c:1001 [inline] smack_inode_init_security+0x459/0x600 security/smack/smack_lsm.c:1079 security_inode_init_security+0x208/0x3e0 security/security.c:1354 shmem_symlink+0xe0/0x4d0 mm/shmem.c:4071 vfs_symlink+0x18b/0x330 fs/namei.c:5794 filename_symlinkat+0x1cd/0x420 fs/namei.c:5819 __do_sys_symlinkat fs/namei.c:5839 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5834 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6581: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x1c5/0x6d0 mm/slub.c:6802 security_inode_init_security+0x32d/0x3e0 security/security.c:1373 shmem_symlink+0xe0/0x4d0 mm/shmem.c:4071 vfs_symlink+0x18b/0x330 fs/namei.c:5794 filename_symlinkat+0x1cd/0x420 fs/namei.c:5819 __do_sys_symlinkat fs/namei.c:5839 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5834 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888021367b80 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of freed 8-byte region [ffff888021367b80, ffff888021367b88) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888021367b20 pfn:0x21367 flags: 0x80000000000200(workingset|node=0|zone=1) page_type: f5(slab) raw: 0080000000000200 ffff88813ffbd500 ffffea0000b40490 ffffea000099df90 raw: ffff888021367b20 0000000000800074 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 10, tgid 10 (kworker/0:1), ts 4807172555 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2591/0x2600 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x230/0x5c0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x339/0x690 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x54b/0x790 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] acpi_ex_allocate_name_string+0x79/0x290 drivers/acpi/acpica/exnames.c:66 acpi_ex_get_name_string+0x488/0xa90 drivers/acpi/acpica/exnames.c:367 acpi_ds_create_operand+0x5c7/0xbe0 drivers/acpi/acpica/dsutils.c:446 acpi_ds_create_operands+0x3fc/0x770 drivers/acpi/acpica/dsutils.c:707 acpi_ds_eval_buffer_field_operands+0x85/0x340 drivers/acpi/acpica/dsopcode.c:290 acpi_ds_exec_end_op+0xc8d/0x1b00 drivers/acpi/acpica/dswexec.c:548 acpi_ps_parse_loop+0xfa3/0x23f0 drivers/acpi/acpica/psloop.c:553 acpi_ps_parse_aml+0x388/0x1020 drivers/acpi/acpica/psparse.c:489 acpi_ps_execute_method+0x89d/0xa70 drivers/acpi/acpica/psxface.c:190 page_owner free stack trace missing Memory state around the buggy address: ffff888021367a80: 00 fc fc fc fa fc fc fc 06 fc fc fc fa fc fc fc ffff888021367b00: 05 fc fc fc fa fc fc fc 05 fc fc fc 00 fc fc fc >ffff888021367b80: fa fc fc fc fa fc fc fc 07 fc fc fc 07 fc fc fc ^ ffff888021367c00: 05 fc fc fc 06 fc fc fc 06 fc fc fc 06 fc fc fc ffff888021367c80: fa fc fc fc fa fc fc fc fa fc fc fc 07 fc fc fc ==================================================================