================================================================== BUG: KASAN: slab-use-after-free in force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 Read of size 8 at addr ffff888023f76800 by task syz.2.9405/15666 CPU: 0 UID: 0 PID: 15666 Comm: syz.2.9405 Tainted: G U I syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 full_proxy_write+0x12e/0x1a0 fs/debugfs/file.c:388 vfs_write+0x29d/0x11d0 fs/read_write.c:684 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f281e38ebe9 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:00007f281f1f1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f281e5b6090 RCX: 00007f281e38ebe9 RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f281e411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f281e5b6128 R14: 00007f281e5b6090 R15: 00007ffd94e7ed88 Allocated by task 14928: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4365 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] mpi_alloc_limb_space+0x31/0x60 lib/crypto/mpi/mpiutil.c:66 mpi_powm+0xbe2/0x1bf0 lib/crypto/mpi/mpi-pow.c:157 _rsa_enc crypto/rsa.c:62 [inline] rsa_enc+0x1fe/0x3b0 crypto/rsa.c:141 crypto_akcipher_encrypt include/crypto/akcipher.h:279 [inline] rsassa_pkcs1_verify+0x4ff/0xb60 crypto/rsassa-pkcs1.c:255 crypto_sig_verify include/crypto/sig.h:221 [inline] public_key_verify_signature+0x66f/0x970 crypto/asymmetric_keys/public_key.c:428 pkcs7_verify_one crypto/asymmetric_keys/pkcs7_verify.c:354 [inline] pkcs7_verify+0x32f/0x1b20 crypto/asymmetric_keys/pkcs7_verify.c:442 verify_pkcs7_message_sig+0xdd/0x250 certs/system_keyring.c:329 verify_pkcs7_signature+0x6d/0xa0 certs/system_keyring.c:412 regdb_has_valid_signature net/wireless/reg.c:785 [inline] valid_regdb+0x211/0x590 net/wireless/reg.c:829 reg_reload_regdb+0x11a/0x460 net/wireless/reg.c:1084 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 14928: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 mpi_free_limb_space+0x1f/0x30 lib/crypto/mpi/mpiutil.c:74 mpi_powm+0x3e4/0x1bf0 lib/crypto/mpi/mpi-pow.c:306 _rsa_enc crypto/rsa.c:62 [inline] rsa_enc+0x1fe/0x3b0 crypto/rsa.c:141 crypto_akcipher_encrypt include/crypto/akcipher.h:279 [inline] rsassa_pkcs1_verify+0x4ff/0xb60 crypto/rsassa-pkcs1.c:255 crypto_sig_verify include/crypto/sig.h:221 [inline] public_key_verify_signature+0x66f/0x970 crypto/asymmetric_keys/public_key.c:428 pkcs7_verify_one crypto/asymmetric_keys/pkcs7_verify.c:354 [inline] pkcs7_verify+0x32f/0x1b20 crypto/asymmetric_keys/pkcs7_verify.c:442 verify_pkcs7_message_sig+0xdd/0x250 certs/system_keyring.c:329 verify_pkcs7_signature+0x6d/0xa0 certs/system_keyring.c:412 regdb_has_valid_signature net/wireless/reg.c:785 [inline] valid_regdb+0x211/0x590 net/wireless/reg.c:829 reg_reload_regdb+0x11a/0x460 net/wireless/reg.c:1084 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888023f76800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff888023f76800, ffff888023f76c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888023f76800 pfn:0x23f70 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b841dc0 ffffea0001e25410 ffffea00009ea810 raw: ffff888023f76800 0000000000100007 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b841dc0 ffffea0001e25410 ffffea00009ea810 head: ffff888023f76800 0000000000100007 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00008fdc01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 9, tgid 9 (kworker/0:0), ts 79058837405, free_ts 78922481728 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x247/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] neigh_alloc net/core/neighbour.c:522 [inline] ___neigh_create+0x14e6/0x28c0 net/core/neighbour.c:656 ip6_finish_output2+0x1299/0x2020 net/ipv6/ip6_output.c:132 __ip6_finish_output+0x3cd/0x1010 net/ipv6/ip6_output.c:215 ip6_finish_output net/ipv6/ip6_output.c:226 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x1ca/0x3e0 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:461 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] mld_sendpack+0x9ea/0x1270 net/ipv6/mcast.c:1860 mld_send_cr net/ipv6/mcast.c:2159 [inline] mld_ifc_work+0x740/0xbf0 net/ipv6/mcast.c:2698 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 page last free pid 5867 tgid 5867 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4236 lsm_file_alloc security/security.c:733 [inline] security_file_alloc+0x34/0x2b0 security/security.c:2888 init_file+0x93/0x4c0 fs/file_table.c:159 alloc_empty_file+0x73/0x1e0 fs/file_table.c:241 alloc_file fs/file_table.c:354 [inline] alloc_file_pseudo+0x13a/0x230 fs/file_table.c:383 sock_alloc_file+0x50/0x210 net/socket.c:470 sock_map_fd net/socket.c:500 [inline] __sys_socket+0x1c0/0x260 net/socket.c:1740 __do_sys_socket net/socket.c:1745 [inline] __se_sys_socket net/socket.c:1743 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888023f76700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888023f76780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888023f76800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023f76880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023f76900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================