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BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:641 [inline]
BUG: KASAN: use-after-free in string+0x20f/0x2a0 lib/vsprintf.c:723
Read of size 1 at addr ffff888101fefb68 by task syz.4.3581/12060

CPU: 1 PID: 12060 Comm: syz.4.3581 Tainted: G        W         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:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 string_nocheck lib/vsprintf.c:641 [inline]
 string+0x20f/0x2a0 lib/vsprintf.c:723
 vsnprintf+0xec5/0x1990 lib/vsprintf.c:2689
 seq_vprintf fs/seq_file.c:398 [inline]
 seq_printf+0x185/0x280 fs/seq_file.c:413
 show_interrupts+0x921/0xa90 kernel/irq/proc.c:526
 traverse+0x1f2/0x590 fs/seq_file.c:111
 seq_lseek+0x13b/0x260 fs/seq_file.c:323
 pde_lseek fs/proc/inode.c:283 [inline]
 proc_reg_llseek+0x1d6/0x2b0 fs/proc/inode.c:294
 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
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8f59e94159
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:00007f8f588ed028 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 00007f8f5a11bfa0 RCX: 00007f8f59e94159
RDX: 0000000000000000 RSI: 0000002000000008 RDI: 0000000000000008
RBP: 00007f8f59f2b06b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f5a11c038 R14: 00007f8f5a11bfa0 R15: 00007ffe364abc98

Allocated by task 8964:
 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:430 [inline]
 ____kasan_kmalloc mm/kasan/common.c:509 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518
 kasan_kmalloc include/linux/kasan.h:254 [inline]
 __kmalloc+0x19f/0x330 mm/slub.c:4038
 __kmalloc_node include/linux/slab.h:421 [inline]
 kmalloc_node include/linux/slab.h:578 [inline]
 __vmalloc_area_node mm/vmalloc.c:2520 [inline]
 __vmalloc_node_range+0x294/0x7a0 mm/vmalloc.c:2629
 __vmalloc_node mm/vmalloc.c:2689 [inline]
 vzalloc+0x78/0x90 mm/vmalloc.c:2742
 alloc_counters+0x65/0x530 net/ipv4/netfilter/ip_tables.c:800
 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:822 [inline]
 get_entries net/ipv4/netfilter/ip_tables.c:1021 [inline]
 do_ipt_get_ctl+0xa26/0x1100 net/ipv4/netfilter/ip_tables.c:1666
 nf_getsockopt+0x26d/0x290 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x134c/0x17a0 net/ipv4/ip_sockglue.c:1797
 tcp_getsockopt+0x1e2/0x1ff0 net/ipv4/tcp.c:4049
 sock_common_getsockopt+0x98/0xb0 net/core/sock.c:3298
 __sys_getsockopt+0x201/0x370 net/socket.c:2188
 __do_sys_getsockopt net/socket.c:2203 [inline]
 __se_sys_getsockopt net/socket.c:2200 [inline]
 __x64_sys_getsockopt+0xbf/0xd0 net/socket.c:2200
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 11544:
 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:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kfree+0xc0/0x270 mm/slub.c:4196
 put_fs_context+0x66f/0x7c0 fs/fs_context.c:454
 do_new_mount+0x314/0xa30 fs/namespace.c:3010
 path_mount+0x581/0xca0 fs/namespace.c:3336
 do_mount fs/namespace.c:3349 [inline]
 __do_sys_mount fs/namespace.c:3557 [inline]
 __se_sys_mount+0x320/0x390 fs/namespace.c:3534
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888101fefb68
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 8-byte region [ffff888101fefb68, ffff888101fefb70)
The buggy address belongs to the page:
page:ffffea000407fbc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101fef
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea00042b5a80 0000000700000007 ffff888100043c80
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 1612187229, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 __kmalloc+0x1f9/0x330 mm/slub.c:4034
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [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_evaluate_integer+0x103/0x1e0 drivers/acpi/utils.c:279
 acpi_bus_get_status_handle drivers/acpi/bus.c:83 [inline]
 acpi_bus_get_status+0x171/0x200 drivers/acpi/bus.c:112
 acpi_pci_link_set+0x53f/0xaa0 drivers/acpi/pci_link.c:351
 acpi_pci_link_allocate drivers/acpi/pci_link.c:589 [inline]
 acpi_pci_link_allocate_irq+0x94c/0xd50 drivers/acpi/pci_link.c:640
 acpi_pci_irq_enable+0x202/0x680 drivers/acpi/pci_irq.c:438
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888101fefa00: 00 fc fc fc fc fa fc fc fc fc fa fc fc fc fc 00
 ffff888101fefa80: fc fc fc fc fa fc fc fc fc 00 fc fc fc fc fa fc
>ffff888101fefb00: fc fc fc fa fc fc fc fc 00 fc fc fc fc fa fc fc
                                                          ^
 ffff888101fefb80: fc fc fa fc fc fc fc 00 fc fc fc fc 00 fc fc fc
 ffff888101fefc00: fc fa fc fc fc fc fa fc fc fc fc 00 fc fc fc fc
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