================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:642 [inline] BUG: KASAN: use-after-free in string+0x20f/0x2a0 lib/vsprintf.c:724 Read of size 1 at addr ffff888101be73e8 by task syz.3.1409/5865 CPU: 0 PID: 5865 Comm: syz.3.1409 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 string_nocheck lib/vsprintf.c:642 [inline] string+0x20f/0x2a0 lib/vsprintf.c:724 vsnprintf+0xec5/0x1990 lib/vsprintf.c:2811 seq_vprintf fs/seq_file.c:407 [inline] seq_printf+0x185/0x280 fs/seq_file.c:422 show_interrupts+0x91d/0xa90 kernel/irq/proc.c:527 traverse+0x1f2/0x590 fs/seq_file.c:111 seq_lseek+0x13b/0x260 fs/seq_file.c:323 proc_reg_llseek+0x19f/0x280 fs/proc/inode.c:284 vfs_llseek fs/read_write.c:300 [inline] ksys_lseek fs/read_write.c:313 [inline] __do_sys_lseek fs/read_write.c:324 [inline] __se_sys_lseek fs/read_write.c:322 [inline] __x64_sys_lseek+0x181/0x200 fs/read_write.c:322 x64_sys_call+0x989/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:9 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5cb3df81d9 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:00007f5cb2851028 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f5cb407ffa0 RCX: 00007f5cb3df81d9 RDX: 0000000000000000 RSI: 0000002000000008 RDI: 0000000000000003 RBP: 00007f5cb3e8f888 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5cb4080038 R14: 00007f5cb407ffa0 R15: 00007ffd3f1e0a08 Allocated by task 5720: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc_track_caller+0x13c/0x2c0 mm/slub.c:4959 memdup_user mm/util.c:177 [inline] strndup_user+0x74/0x150 mm/util.c:236 copy_mount_string fs/namespace.c:3275 [inline] __do_sys_mount fs/namespace.c:3578 [inline] __se_sys_mount+0xdf/0x390 fs/namespace.c:3565 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3565 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 5720: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 __do_sys_mount fs/namespace.c:3592 [inline] __se_sys_mount+0x34b/0x390 fs/namespace.c:3565 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3565 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888101be73e8 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [ffff888101be73e8, ffff888101be73f0) The buggy address belongs to the page: page:ffffea000406f9c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101be7 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 dead000000000100 dead000000000122 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, ts 1771010317, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc+0x16a/0x2c0 mm/slub.c:4432 kmalloc include/linux/slab.h:624 [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/0x1190 drivers/acpi/acpica/dswexec.c:385 acpi_ps_parse_loop+0xbff/0x19f0 drivers/acpi/acpica/psloop.c:525 acpi_ps_parse_aml+0x214/0x9a0 drivers/acpi/acpica/psparse.c:475 acpi_ps_execute_method+0x681/0x7b0 drivers/acpi/acpica/psxface.c:190 acpi_ns_evaluate+0x650/0xa20 drivers/acpi/acpica/nseval.c:205 page_owner free stack trace missing Memory state around the buggy address: ffff888101be7280: 00 fc fc fc fc fa fc fc fc fc fa fc fc fc fc 06 ffff888101be7300: fc fc fc fc fa fc fc fc fc fa fc fc fc fc fa fc >ffff888101be7380: fc fc fc 06 fc fc fc fc fa fc fc fc fc fa fc fc ^ ffff888101be7400: fc fc fa fc fc fc fc fa fc fc fc fc fa fc fc fc ffff888101be7480: fc 07 fc fc fc fc 06 fc fc fc fc fa fc fc fc fc ==================================================================