================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:646 [inline] BUG: KASAN: slab-use-after-free in string+0x20f/0x2b0 lib/vsprintf.c:728 Read of size 1 at addr ffff888105ac3f40 by task syz.3.1135/3549 CPU: 0 UID: 0 PID: 3549 Comm: syz.3.1135 Not tainted syzkaller #0 93cd2a7db6251899ee82c41fb24ebb4b8e8a6534 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 print_address_description+0x71/0x210 mm/kasan/report.c:377 print_report+0x4a/0x70 mm/kasan/report.c:481 kasan_report+0x162/0x1a0 mm/kasan/report.c:594 __asan_report_load1_noabort+0x18/0x20 mm/kasan/report_generic.c:378 string_nocheck lib/vsprintf.c:646 [inline] string+0x20f/0x2b0 lib/vsprintf.c:728 vsnprintf+0xe65/0x1ad0 lib/vsprintf.c:2803 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x189/0x290 fs/seq_file.c:406 show_interrupts+0x6d2/0x7f0 kernel/irq/proc.c:524 seq_read_iter+0xa7d/0xf30 fs/seq_file.c:272 proc_reg_read_iter+0x1ea/0x2c0 fs/proc/inode.c:299 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x60b/0xc70 fs/read_write.c:570 ksys_read+0x145/0x260 fs/read_write.c:713 __do_sys_read fs/read_write.c:723 [inline] __se_sys_read fs/read_write.c:721 [inline] __x64_sys_read+0x7f/0x90 fs/read_write.c:721 x64_sys_call+0x2638/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f2f6539e159 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:00007f2f66280028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f2f65625fa0 RCX: 00007f2f6539e159 RDX: 00000000000000bd RSI: 0000200000006a00 RDI: 0000000000000003 RBP: 00007f2f6543506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2f65626038 R14: 00007f2f65625fa0 R15: 00007fff47f12fe8 Allocated by task 1: kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565 poison_kmalloc_redzone mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396 kasan_kmalloc include/linux/kasan.h:261 [inline] __do_kmalloc_node mm/slub.c:4395 [inline] __kmalloc_node_track_caller_noprof+0x24e/0x4f0 mm/slub.c:4414 kvasprintf+0xf1/0x260 lib/kasprintf.c:25 kasprintf+0xe3/0x140 lib/kasprintf.c:59 serial_core_add_one_port drivers/tty/serial/serial_core.c:3171 [inline] serial_core_register_port+0x83b/0x23c0 drivers/tty/serial/serial_core.c:3414 serial_ctrl_register_port+0x21/0x30 drivers/tty/serial/serial_ctrl.c:41 uart_add_one_port+0x21/0x30 drivers/tty/serial/serial_port.c:143 serial8250_register_8250_port+0x17ab/0x21d0 drivers/tty/serial/8250/8250_core.c:823 serial_pnp_probe+0x54b/0x750 drivers/tty/serial/8250/8250_pnp.c:490 pnp_device_probe+0x319/0x4e0 drivers/pnp/driver.c:111 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2e4/0x8b0 drivers/base/dd.c:657 __driver_probe_device+0x193/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __driver_attach+0x422/0x5e0 drivers/base/dd.c:1215 bus_for_each_dev+0x249/0x2d0 drivers/base/bus.c:370 driver_attach+0x46/0x50 drivers/base/dd.c:1233 bus_add_driver+0x393/0x730 drivers/base/bus.c:675 driver_register+0x2b7/0x3c0 drivers/base/driver.c:246 pnp_register_driver+0x81/0x90 drivers/pnp/driver.c:280 serial8250_pnp_init+0x19/0x20 drivers/tty/serial/8250/8250_pnp.c:540 serial8250_init+0xcc/0x1d0 drivers/tty/serial/8250/8250_platform.c:324 do_one_initcall+0x1e8/0x6a0 init/main.c:1406 do_initcall_level+0x174/0x2e5 init/main.c:1468 do_initcalls+0x7e/0x160 init/main.c:1484 do_basic_setup+0x95/0xb0 init/main.c:1503 kernel_init_freeable+0x2b1/0x400 init/main.c:1717 kernel_init+0x21/0x1e0 init/main.c:1606 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 3334: kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:249 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2445 [inline] slab_free mm/slub.c:4714 [inline] kfree+0x158/0x440 mm/slub.c:4875 serial_core_remove_one_port drivers/tty/serial/serial_core.c:3273 [inline] serial_core_unregister_port+0x469/0xa50 drivers/tty/serial/serial_core.c:3449 serial_ctrl_unregister_port+0x21/0x30 drivers/tty/serial/serial_ctrl.c:46 uart_remove_one_port+0x21/0x30 drivers/tty/serial/serial_port.c:149 serial8250_unregister_port+0x1cc/0x6b0 drivers/tty/serial/8250/8250_core.c:886 serial_pnp_remove+0x5d/0xa0 drivers/tty/serial/8250/8250_pnp.c:507 pnp_device_remove+0x8a/0x270 drivers/pnp/driver.c:133 device_remove drivers/base/dd.c:567 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4aa/0x830 drivers/base/dd.c:1295 device_driver_detach+0x3f/0x50 drivers/base/dd.c:1331 unbind_store+0x1ab/0x1f0 drivers/base/bus.c:244 drv_attr_store+0x8e/0xb0 drivers/base/bus.c:125 sysfs_kf_write+0x13e/0x160 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x75f/0xfd0 fs/read_write.c:684 ksys_write+0x145/0x260 fs/read_write.c:737 __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x7f/0x90 fs/read_write.c:746 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff888105ac3f40 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of freed 8-byte region [ffff888105ac3f40, ffff888105ac3f48) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105ac3 flags: 0x4000000000000000(zone=1) page_type: f5(slab) raw: 4000000000000000 ffff888100041500 ffffea00044e1880 dead000000000002 raw: 0000000000000000 0000000000800080 00000001f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 2870681612, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1864 prep_new_page+0x2d/0x180 mm/page_alloc.c:1872 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3949 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5316 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1 allocate_slab+0x69/0x430 mm/slub.c:2687 new_slab mm/slub.c:2741 [inline] ___slab_alloc+0x591/0x8c0 mm/slub.c:3934 __slab_alloc mm/slub.c:4025 [inline] __slab_alloc_node mm/slub.c:4078 [inline] slab_alloc_node mm/slub.c:4239 [inline] __do_kmalloc_node mm/slub.c:4394 [inline] __kmalloc_noprof+0x2fc/0x510 mm/slub.c:4407 kmalloc_noprof include/linux/slab.h:886 [inline] kzalloc_noprof include/linux/slab.h:1117 [inline] acpi_ns_internalize_name+0x2df/0x490 drivers/acpi/acpica/nsutils.c:331 acpi_ns_get_node_unlocked drivers/acpi/acpica/nsutils.c:666 [inline] acpi_ns_get_node+0x1ab/0x360 drivers/acpi/acpica/nsutils.c:726 acpi_ns_evaluate+0x373/0xa60 drivers/acpi/acpica/nseval.c:62 acpi_ut_evaluate_object+0x15a/0x5b0 drivers/acpi/acpica/uteval.c:60 acpi_rs_get_method_data+0x9e/0x120 drivers/acpi/acpica/rsutils.c:650 acpi_walk_resources+0x154/0x4f0 drivers/acpi/acpica/rsxface.c:616 acpi_pci_link_get_current+0x1fb/0x3c0 drivers/acpi/pci_link.c:256 acpi_pci_link_set+0x637/0xaf0 drivers/acpi/pci_link.c:362 page_owner free stack trace missing Memory state around the buggy address: ffff888105ac3e00: 00 fc fc fc 06 fc fc fc 06 fc fc fc fa fc fc fc ffff888105ac3e80: 00 fc fc fc fa fc fc fc fa fc fc fc 06 fc fc fc >ffff888105ac3f00: 00 fc fc fc fa fc fc fc fa fc fc fc 00 fc fc fc ^ ffff888105ac3f80: fa fc fc fc 04 fc fc fc fa fc fc fc 06 fc fc fc ffff888105ac4000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================