================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] BUG: KASAN: slab-use-after-free in string+0x216/0x2d0 lib/vsprintf.c:730 Read of size 1 at addr ffff88805b0abc60 by task syz.0.245/6620 CPU: 0 UID: 0 PID: 6620 Comm: syz.0.245 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 string_nocheck lib/vsprintf.c:648 [inline] string+0x216/0x2d0 lib/vsprintf.c:730 vsnprintf+0x74a/0xef0 lib/vsprintf.c:2949 vscnprintf lib/vsprintf.c:3018 [inline] scnprintf+0x102/0x190 lib/vsprintf.c:3071 f_midi2_opts_str_show drivers/usb/gadget/function/f_midi2.c:2187 [inline] f_midi2_opts_iface_name_show+0x70/0xa0 drivers/usb/gadget/function/f_midi2.c:2592 fill_read_buffer fs/configfs/file.c:68 [inline] configfs_read_iter+0x2b7/0x620 fs/configfs/file.c:88 __kernel_read+0x4ca/0x960 fs/read_write.c:532 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline] ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300 process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685 security_file_post_open+0xb3/0x260 security/security.c:2755 do_open fs/namei.c:4839 [inline] path_openat+0x1485/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_open fs/open.c:1431 [inline] __se_sys_open fs/open.c:1427 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1427 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb5e279e0d9 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:00007fb5e3734028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fb5e2a25fa0 RCX: 00007fb5e279e0d9 RDX: 0000000000000041 RSI: 0000000000040280 RDI: 00002000000003c0 RBP: 00007fb5e2835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb5e2a26038 R14: 00007fb5e2a25fa0 R15: 00007ffc70eaa258 Allocated by task 6576: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_node_track_caller_noprof+0x4b0/0x720 mm/slub.c:5545 __kmemdup_nul mm/util.c:64 [inline] kstrndup+0x7e/0x160 mm/util.c:120 f_midi2_opts_str_store+0x95/0x270 drivers/usb/gadget/function/f_midi2.c:2205 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6621: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x1c5/0x650 mm/slub.c:6792 f_midi2_opts_str_store+0xc5/0x270 drivers/usb/gadget/function/f_midi2.c:2211 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805b0abc60 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of freed 16-byte region [ffff88805b0abc60, ffff88805b0abc70) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5b0ab flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b005640 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000800080 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5614, tgid 5614 (syz-executor), ts 97288225398 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2205/0x2280 mm/page_alloc.c:4001 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5498 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x2c4/0x6b0 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kvmalloc_node_noprof+0x638/0x820 mm/slub.c:7005 xt_jumpstack_alloc net/netfilter/x_tables.c:1449 [inline] do_replace_table+0x18c/0x610 net/netfilter/x_tables.c:1486 xt_replace_table+0x2c/0x140 net/netfilter/x_tables.c:1545 __do_replace+0x161/0x9a0 net/ipv6/netfilter/ip6_tables.c:1079 do_replace net/ipv6/netfilter/ip6_tables.c:1156 [inline] do_ip6t_set_ctl+0xb45/0xe30 net/ipv6/netfilter/ip6_tables.c:1643 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2393 __sys_setsockopt net/socket.c:2418 [inline] __do_sys_setsockopt net/socket.c:2424 [inline] __se_sys_setsockopt net/socket.c:2421 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2421 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5614 tgid 5614 ts 97288140720 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc8f/0xd80 mm/page_alloc.c:3020 ___free_pages_bulk mm/kasan/shadow.c:333 [inline] __kasan_populate_vmalloc_do mm/kasan/shadow.c:385 [inline] __kasan_populate_vmalloc+0x12d/0x1c0 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:580 [inline] alloc_vmap_area+0xd1a/0x1420 mm/vmalloc.c:2180 __get_vm_area_node+0x1f2/0x300 mm/vmalloc.c:3283 __vmalloc_node_range_noprof+0x343/0x1540 mm/vmalloc.c:4214 __vmalloc_node_noprof mm/vmalloc.c:4315 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4393 __do_replace+0xb2/0x9a0 net/ipv6/netfilter/ip6_tables.c:1061 do_replace net/ipv6/netfilter/ip6_tables.c:1156 [inline] do_ip6t_set_ctl+0xb45/0xe30 net/ipv6/netfilter/ip6_tables.c:1643 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2393 __sys_setsockopt net/socket.c:2418 [inline] __do_sys_setsockopt net/socket.c:2424 [inline] __se_sys_setsockopt net/socket.c:2421 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2421 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805b0abb00: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ffff88805b0abb80: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc >ffff88805b0abc00: 00 00 fc fc fa fb fc fc fa fb fc fc fa fb fc fc ^ ffff88805b0abc80: fa fb fc fc fa fb fc fc fa fb fc fc 00 00 fc fc ffff88805b0abd00: fa fb fc fc fa fb fc fc 00 00 fc fc fa fb fc fc ==================================================================