From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1E2619C553 for ; Sat, 20 Jun 2026 00:40:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781916033; cv=none; b=ONW7vjMvoBN6ptSBsis9MQL+6dVDMWT/HrUguoW/ehq93dNjaGCmBU2HmO4V68NkNTM+A3CZBbxVWvxfS6CAf4WWahmwGnxAnuyg4SJNnIeJv8dHfHNA/IsE0NLj8ak1TCoIN1B9Cc6dYx/sBe9Yge8BLcNEEA89LqjTkXp08W4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781916033; c=relaxed/simple; bh=LjYDAm+Z/FebfeRxRe3CvHXaOECgFKKITIZ4ar5M0Qk=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=ka+oBDFF4rp+acYYZzsI4nCqXieBhUU0AONtbZ8ZSpg41QliVTsfos0KT4h2EF/s/DXeh0ccgFWJ0KUXX4XtMCspl21/Dbj/8aFDhRv0TI0VTmfmo5tpqBOQKQZeLBZ+hcdLDjpDaRV1WqOEzNaRa7tOKPeVm1BaAn+dadxvTy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f77.google.com with SMTP id 46e09a7af769-7e6db540d17so6118767a34.0 for ; Fri, 19 Jun 2026 17:40:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781916031; x=1782520831; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=woZgCBy3FjjwMpNyw0y5OUQwQzV6D7KT7UuiRnIqXD0=; b=SuOvgJVBr3glAKiFMjW1EnUexqXm0r4RE+1te4MG5ec9Avg+EPKTAwobilq889ISle 2YhspGf3SYER7ASPxbHM/wxd34tADn1puPrDcV6m0iEjjyayBP1sPyvAoH9mrVLzZsI2 NHHKSUOAYP8RIKAr3gsHyKdk/1oMS5/0Vk4a85jZy5GXynU3a316hdFPWsPfd55Jilvu in+Hkv/M+9UbaIzm3Zv2CEyxaFbn2FF70z1RBbOw5CGZcSmY5OsOWqhxGpiXl2uQPq53 XWDNdEaIqNeml5VE3IUWfoWoi3lUSRercaJDbS8RNj6FYRujSP40ea3NmHtjkGypM3JE 5reA== X-Gm-Message-State: AOJu0Yz+eJoPicXvp9dy17fqTMb9LD2tmQDqKL+LDB2EssEse8aXBlH4 kQlRc0ouiNFgAR4l7vU61hoLpeqTPM+hsA/zBLyClkGHipVSjSMlyxUCH/4EmJ1tMPO0Ns7kv5I mTDKTmdqODyIQEKWZ6RrgAax//wuJZms9PV8Ix0JJjq30WD8XYotLuqa/z4zvcA== Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:120c:b0:489:5c86:ba96 with SMTP id 5614622812f47-4896aab1714mr4575752b6e.17.1781916030935; Fri, 19 Jun 2026 17:40:30 -0700 (PDT) Date: Fri, 19 Jun 2026 17:40:30 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a35e17e.6813c476.3c3d96.0001.GAE@google.com> Subject: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in bt_accept_dequeue From: syzbot To: linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, luiz.dentz@gmail.com, marcel@holtmann.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 8c13415c8a43 Merge tag 'media/v7.2-1' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12f94d56580000 kernel config: https://syzkaller.appspot.com/x/.config?x=6a86d80fdec25236 dashboard link: https://syzkaller.appspot.com/bug?extid=674ff7e4d7fdfd572afc compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3ecc105c1b32/disk-8c13415c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/cda6390db722/vmlinux-8c13415c.xz kernel image: https://storage.googleapis.com/syzbot-assets/5f3d326d7d36/bzImage-8c13415c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+674ff7e4d7fdfd572afc@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:283 [inline] BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:366 [inline] BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:383 [inline] BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:839 [inline] BUG: KASAN: slab-use-after-free in bt_accept_dequeue+0x6bd/0x920 net/bluetooth/af_bluetooth.c:348 Write of size 4 at addr ffff888036a17080 by task syz.2.3018/19569 CPU: 0 UID: 0 PID: 19569 Comm: syz.2.3018 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:283 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] sock_hold include/net/sock.h:839 [inline] bt_accept_dequeue+0x6bd/0x920 net/bluetooth/af_bluetooth.c:348 l2cap_sock_cleanup_listen+0x47/0x4d0 net/bluetooth/l2cap_sock.c:1517 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1466 __sock_release+0xb3/0x260 net/socket.c:710 sock_close+0x1c/0x30 net/socket.c:1501 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 get_signal+0x1bd/0x21e0 kernel/signal.c:2810 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6feb9ce59 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:00007fc6ff9a4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000120 RAX: fffffffffffffe00 RBX: 00007fc6fee15fa0 RCX: 00007fc6feb9ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fc6fec32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc6fee16038 R14: 00007fc6fee15fa0 R15: 00007ffdf85f63a8 Allocated by task 19587: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_noprof+0x302/0x840 mm/slub.c:5347 _kmalloc_noprof include/linux/slab.h:973 [inline] sk_prot_alloc+0x10b/0x2a0 net/core/sock.c:2252 sk_alloc+0x36/0xe80 net/core/sock.c:2308 bt_sock_alloc+0x3b/0x3c0 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc.constprop.0+0x33/0x1e0 net/bluetooth/l2cap_sock.c:1983 l2cap_sock_new_connection_cb+0x10f/0x260 net/bluetooth/l2cap_sock.c:1562 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7481 hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] hci_remote_features_evt+0x4f4/0x9b0 net/bluetooth/hci_event.c:3764 hci_event_func net/bluetooth/hci_event.c:7800 [inline] hci_event_packet+0x8e9/0xcd0 net/bluetooth/hci_event.c:7851 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4039 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 19569: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6310 [inline] kfree+0x22b/0x6c0 mm/slub.c:6625 sk_prot_free net/core/sock.c:2291 [inline] __sk_destruct+0x88c/0xab0 net/core/sock.c:2391 sk_destruct+0xc8/0xf0 net/core/sock.c:2419 __sk_free+0xf4/0x3e0 net/core/sock.c:2430 sk_free+0x61/0x90 net/core/sock.c:2441 sock_put include/net/sock.h:2020 [inline] bt_accept_unlink+0x22a/0x370 net/bluetooth/af_bluetooth.c:267 bt_accept_dequeue+0x791/0x920 net/bluetooth/af_bluetooth.c:336 l2cap_sock_cleanup_listen+0x47/0x4d0 net/bluetooth/l2cap_sock.c:1517 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1466 __sock_release+0xb3/0x260 net/socket.c:710 sock_close+0x1c/0x30 net/socket.c:1501 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 get_signal+0x1bd/0x21e0 kernel/signal.c:2810 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888036a17000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of freed 2048-byte region [ffff888036a17000, ffff888036a17800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888036a16000 pfn:0x36a10 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 ffff88813fe3b000 ffffea000132c210 ffffea00009e2810 raw: ffff888036a16000 0000000800080005 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fe3b000 ffffea000132c210 ffffea00009e2810 head: ffff888036a16000 0000000800080005 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 10, tgid 10 (kworker/0:1), ts 48507424327, free_ts 27518573283 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x812/0x3d20 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x27c/0x2b60 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab mm/slub.c:3404 [inline] new_slab+0xa2/0x670 mm/slub.c:3447 refill_objects+0xe3/0x430 mm/slub.c:7241 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x375/0x660 mm/slub.c:4692 alloc_from_pcs mm/slub.c:4790 [inline] slab_alloc_node mm/slub.c:4924 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_node_track_caller_noprof+0x6b5/0x890 mm/slub.c:5438 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:637 __alloc_skb+0x185/0x710 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1386 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1773 add_grhead+0x299/0x340 net/ipv6/mcast.c:1884 add_grec+0x1389/0x1930 net/ipv6/mcast.c:2023 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x3c5/0xc10 net/ipv6/mcast.c:2694 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 page last free pid 5380 tgid 5380 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0x794/0x10a0 mm/page_alloc.c:2938 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] kmem_cache_alloc_noprof+0x241/0x6d0 mm/slub.c:4946 vm_area_alloc+0x1f/0x160 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2547 [inline] __mmap_region+0x104d/0x2dd0 mm/vma.c:2771 mmap_region+0x35d/0x620 mm/vma.c:2857 do_mmap+0xc63/0x12f0 mm/mmap.c:560 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888036a16f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888036a17000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888036a17080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888036a17100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888036a17180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup