================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:641 [inline] BUG: KASAN: use-after-free in string+0x21f/0x2b0 lib/vsprintf.c:723 Read of size 1 at addr ffff88816776d4b9 by task syz.5.5241/19615 CPU: 1 PID: 19615 Comm: syz.5.5241 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 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+0xe2/0x130 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+0x21f/0x2b0 lib/vsprintf.c:723 vsnprintf+0xf20/0x1960 lib/vsprintf.c:2689 seq_vprintf fs/seq_file.c:398 [inline] seq_printf+0x175/0x260 fs/seq_file.c:413 input_devices_seq_show+0x1a6/0x650 drivers/input/input.c:1186 seq_read_iter+0x93f/0xd30 fs/seq_file.c:272 seq_read+0x3cc/0x4d0 fs/seq_file.c:162 pde_read fs/proc/inode.c:321 [inline] proc_reg_read+0x1c4/0x2b0 fs/proc/inode.c:333 do_loop_readv_writev fs/read_write.c:-1 [inline] do_iter_read+0x44b/0x640 fs/read_write.c:803 vfs_readv fs/read_write.c:921 [inline] do_preadv+0x1f6/0x330 fs/read_write.c:1013 __do_sys_preadv fs/read_write.c:1063 [inline] __se_sys_preadv fs/read_write.c:1058 [inline] __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1058 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd599804ec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd59824c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fd599a5c090 RCX: 00007fd599804ec9 RDX: 0000000000000001 RSI: 00002000000015c0 RDI: 0000000000000006 RBP: 00007fd599887f91 R08: 0000000000207fff R09: 0000000000000000 R10: 00000000000000f6 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd599a5c128 R14: 00007fd599a5c090 R15: 00007ffeae506148 Allocated by task 0: (stack is not available) Freed by task 8469: 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 release_nodes+0x753/0x7d0 drivers/base/devres.c:524 devres_release_all+0x7c/0xa0 drivers/base/devres.c:545 __device_release_driver drivers/base/dd.c:1190 [inline] device_release_driver_internal+0x4cb/0x750 drivers/base/dd.c:1221 device_release_driver+0x19/0x20 drivers/base/dd.c:1244 bus_remove_device+0x2dd/0x340 drivers/base/bus.c:535 device_del+0x696/0xed0 drivers/base/core.c:3452 hid_remove_device drivers/hid/hid-core.c:2512 [inline] hid_destroy_device+0x6a/0x110 drivers/hid/hid-core.c:2531 usbhid_disconnect+0x9f/0xc0 drivers/hid/usbhid/hid-core.c:1448 usb_unbind_interface+0x212/0x8c0 drivers/usb/core/driver.c:459 __device_release_driver drivers/base/dd.c:-1 [inline] device_release_driver_internal+0x4bc/0x750 drivers/base/dd.c:1221 device_release_driver+0x19/0x20 drivers/base/dd.c:1244 bus_remove_device+0x2dd/0x340 drivers/base/bus.c:535 device_del+0x696/0xed0 drivers/base/core.c:3452 usb_disable_device+0x3a8/0x750 drivers/usb/core/message.c:1411 usb_disconnect+0x31e/0x850 drivers/usb/core/hub.c:2310 hub_port_connect drivers/usb/core/hub.c:5338 [inline] hub_port_connect_change drivers/usb/core/hub.c:5639 [inline] port_event drivers/usb/core/hub.c:5805 [inline] hub_event+0x1a88/0x42c0 drivers/usb/core/hub.c:5887 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88816776d400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 185 bytes inside of 512-byte region [ffff88816776d400, ffff88816776d600) The buggy address belongs to the page: page:ffffea00059ddb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16776c head:ffffea00059ddb00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 12371, ts 901934360436, free_ts 901880989749 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 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+0x2a6/0x450 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+0x201/0x330 mm/slub.c:4034 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] neigh_alloc net/core/neighbour.c:439 [inline] ___neigh_create+0x6f0/0x1a20 net/core/neighbour.c:592 __neigh_create+0x31/0x40 net/core/neighbour.c:680 ip6_finish_output2+0x8d1/0x1500 net/ipv6/ip6_output.c:127 __ip6_finish_output+0x5ff/0x790 net/ipv6/ip6_output.c:201 ip6_finish_output+0x33/0x1f0 net/ipv6/ip6_output.c:211 NF_HOOK_COND include/linux/netfilter.h:288 [inline] ip6_output+0x1d1/0x3b0 net/ipv6/ip6_output.c:234 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ndisc_send_skb+0x6f5/0xb40 net/ipv6/ndisc.c:513 ndisc_send_rs+0x6e5/0x960 net/ipv6/ndisc.c:707 addrconf_dad_completed+0x97f/0xe80 net/ipv6/addrconf.c:4287 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5431 [inline] __free_pages+0xdd/0x380 mm/page_alloc.c:5440 kfree+0x1e7/0x270 mm/slub.c:4193 kvfree+0x35/0x40 mm/util.c:647 bpf_check+0x8a13/0xd680 kernel/bpf/verifier.c:12784 bpf_prog_load+0xf5a/0x1420 kernel/bpf/syscall.c:2234 __do_sys_bpf kernel/bpf/syscall.c:4435 [inline] __se_sys_bpf+0x442/0x680 kernel/bpf/syscall.c:4391 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:4391 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88816776d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88816776d400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88816776d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88816776d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88816776d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================