================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:643 [inline] BUG: KASAN: use-after-free in string+0x20f/0x2a0 lib/vsprintf.c:725 Read of size 1 at addr ffff88810b327730 by task syz.5.240/1296 CPU: 1 PID: 1296 Comm: syz.5.240 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 string_nocheck lib/vsprintf.c:643 [inline] string+0x20f/0x2a0 lib/vsprintf.c:725 vsnprintf+0xec5/0x1990 lib/vsprintf.c:2805 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x185/0x280 fs/seq_file.c:406 show_interrupts+0x8f9/0xa00 kernel/irq/proc.c:527 seq_read_iter+0x992/0xd80 fs/seq_file.c:272 proc_reg_read_iter+0x1e0/0x2b0 fs/proc/inode.c:305 call_read_iter include/linux/fs.h:2276 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x46e/0x930 fs/read_write.c:470 ksys_read+0x14a/0x260 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:621 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 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 RIP: 0033:0x7f622c99e159 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:00007f622d8e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f622cc25fa0 RCX: 00007f622c99e159 RDX: 000000000000018b RSI: 0000200000006a00 RDI: 0000000000000005 RBP: 00007f622ca3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f622cc26038 R14: 00007f622cc25fa0 R15: 00007ffd5cfc2488 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 The buggy address belongs to the object at ffff88810b327730 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [ffff88810b327730, ffff88810b327738) The buggy address belongs to the physical page: page:ffffea00042cc9c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810b327758 pfn:0x10b327 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004d13288 ffffea000424f908 ffff888100042300 raw: ffff88810b327758 0000000000660059 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 2203938617, 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] acpi_os_allocate include/acpi/platform/aclinuxex.h:52 [inline] acpi_ex_allocate_name_string drivers/acpi/acpica/exnames.c:66 [inline] acpi_ex_get_name_string+0x5a9/0xca0 drivers/acpi/acpica/exnames.c:367 acpi_ds_create_operand+0x168/0x8b0 drivers/acpi/acpica/dsutils.c:446 acpi_ds_create_operands+0x271/0x410 drivers/acpi/acpica/dsutils.c:707 acpi_ds_exec_end_op+0x28a/0x11a0 drivers/acpi/acpica/dswexec.c:385 acpi_ps_parse_loop+0xc0d/0x19f0 drivers/acpi/acpica/psloop.c:525 acpi_ps_parse_aml+0x214/0x9a0 drivers/acpi/acpica/psparse.c:475 page_owner free stack trace missing Memory state around the buggy address: ffff88810b327600: fc fc fc fa fc fc fc fc fa fc fc fc fc fa fc fc ffff88810b327680: fc fc 00 fc fc fc fc fa fc fc fc fc fa fc fc fc >ffff88810b327700: fc fa fc fc fc fc fb fc fc fc fc fb fc fc fc fc ^ ffff88810b327780: fa fc fc fc fc fa fc fc fc fc fa fc fc fc fc 00 ffff88810b327800: fc fc fc fc fa fc fc fc fc fa fc fc fc fc 00 fc ==================================================================