From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (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 15B9F23C8D5 for ; Fri, 12 Sep 2025 15:46:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757691993; cv=none; b=WF4e43zqIyvaJBamBhocLYTdxF/OptT/NgoZ96aFMD6OW/y9iB1g3o8V3fZCds7N93faT/bmm0UNIs3/WM6x4trySsw/t96NKP5RqtLcLQn4aN0tmrlKSC0wk2hro1JORv5W95vxtfOZbQwDfXJSemi9JEvgUD/uM5pgoNbGbG4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757691993; c=relaxed/simple; bh=y7CSvpwDNoZP/AQb4KkTyNw9yYUr9jxGoEbsLHS93ww=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=atFoGGH5jcspQC3UaE9HSQBNmMojQxaSyLNwjAZIDPYxxy+YsjFD8r2br1e1fvpaZ4xG2IceEB7qAUEqteCJWCljTkEmUKktp34cPLu2wy2Dg179DP9w1nGOs+sSmhl2A2btkjCFJSdqRZ2Pd+EAO36jMbMWcaeOa+ERJwz2DI4= 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=209.85.166.208 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-il1-f208.google.com with SMTP id e9e14a558f8ab-4155725a305so28296825ab.2 for ; Fri, 12 Sep 2025 08:46:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757691990; x=1758296790; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=UmIDwGLt88oK0VrPke850QRBTnWxm93rpkXbpCBvQgY=; b=o3J1W//Vzu4fkw1LdSfqdCmBz2sZUhaylHUQ/wprv5PWAbl0Yb1PF7o/kWJuxhx0Im KlaL2dT1s2oc4WmgJWIf8otYVFpX7+ddBNVozTWVGcswqrLxcT8KPsI7fcjOQ9CcuT/Y VCbWsXw5Hlw9wvdavvpjL0vUahIv0nnCtr3PvPXYAL7H9EHmM+kEOAxnODB0JvHMPAyb ddAZja6qNs7dUtmLL/ckzg2oNubQdun5bOJNEtFg1n3TqTtVJdv0oKpmFtNZL8x4imiw BLztrbZQrCxs98oMBAcfmuFdvAkRuEyAS2KhBt7Ppbadkd+Y4XWdb2EbCwjBWUQ00NJ9 yItQ== X-Forwarded-Encrypted: i=1; AJvYcCUp/JtWUhHqc7uwIUQpUdYgBzgdEjiYzn3FtuqfAzOMV/x5PlZSJkPDytug916dFyXddoV2ZEP8lQUk9gs=@vger.kernel.org X-Gm-Message-State: AOJu0YxDwIDjHDGfTPiuVCbptyO3uAosA/iJbjoaiNdRq+DFs0qYYCRL rwSlKO47MCxfbC/++1KsjWQu8CZFd7qDU1ntdunpM/97DOdHXfcs3Wzpun6zT0WIjz38c5+N3k0 2WyE4rtD3arAHdea8pn4Woc0fCEt9I055+wC6LFe1u1Rhmv2bT1iZRxIKFHw= X-Google-Smtp-Source: AGHT+IG40qt48oLK9UMwkLmihYsue37aN2kGi5xgVYk++JOC1PkU/3f//zf8GtC9EhFdZBkBlOrE3YvxhsLV+ZfY6NePHwn64pb6 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:18cc:b0:41c:ba93:bee0 with SMTP id e9e14a558f8ab-420a4dec279mr46332665ab.28.1757691990269; Fri, 12 Sep 2025 08:46:30 -0700 (PDT) Date: Fri, 12 Sep 2025 08:46:30 -0700 In-Reply-To: <67d84663.050a0220.2ca2c6.0020.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68c44056.a70a0220.3543fc.0036.GAE@google.com> Subject: Re: [syzbot] [bluetooth?] KASAN: wild-memory-access Read in l2cap_connect_cfm From: syzbot To: johan.hedberg@gmail.com, 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" syzbot has found a reproducer for the following issue on: HEAD commit: 590b221ed425 Add linux-next specific files for 20250912 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=161d1934580000 kernel config: https://syzkaller.appspot.com/x/.config?x=9134e501f17b95a4 dashboard link: https://syzkaller.appspot.com/bug?extid=0e4ebcc970728e056324 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=111d1934580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/872439e79d04/disk-590b221e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/09ebcfd707c1/vmlinux-590b221e.xz kernel image: https://storage.googleapis.com/syzbot-assets/e3417bc549df/bzImage-590b221e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0e4ebcc970728e056324@syzkaller.appspotmail.com ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci0: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 Read of size 8 at addr ffff888076dfc480 by task kworker/u9:3/5984 CPU: 1 UID: 0 PID: 5984 Comm: kworker/u9:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci0 hci_rx_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2085 le_conn_complete_evt+0xcd3/0x1220 net/bluetooth/hci_event.c:5761 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5787 hci_event_func net/bluetooth/hci_event.c:7532 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7589 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5984: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5457 kmalloc_noprof include/linux/slab.h:956 [inline] kzalloc_noprof include/linux/slab.h:1090 [inline] l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1906 [inline] l2cap_sock_new_connection_cb+0x182/0x2b0 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x37a/0x1040 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2085 le_conn_complete_evt+0xcd3/0x1220 net/bluetooth/hci_event.c:5761 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5787 hci_event_func net/bluetooth/hci_event.c:7532 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7589 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 6106: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2474 [inline] slab_free mm/slub.c:6181 [inline] kfree+0x199/0x6d0 mm/slub.c:6389 l2cap_sock_cleanup_listen+0xea/0x3e0 net/bluetooth/l2cap_sock.c:1468 l2cap_sock_release+0x6a/0x210 net/bluetooth/l2cap_sock.c:1426 __sock_release net/socket.c:649 [inline] sock_close+0xc3/0x240 net/socket.c:1442 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888076dfc000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888076dfc000, ffff888076dfc800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76df8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a842000 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a842000 0000000000000000 0000000000000001 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001db7e01 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 12, tgid 12 (kworker/u8:0), ts 101722977992, free_ts 59750752696 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3869 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5159 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2986 [inline] allocate_slab+0x8a/0x330 mm/slub.c:3154 new_slab mm/slub.c:3208 [inline] ___slab_alloc+0xbd1/0x13f0 mm/slub.c:4480 __slab_alloc+0x55/0xa0 mm/slub.c:4571 __slab_alloc_node mm/slub.c:4646 [inline] slab_alloc_node mm/slub.c:5056 [inline] __do_kmalloc_node mm/slub.c:5425 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5445 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:600 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:669 alloc_skb include/linux/skbuff.h:1377 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4392 unregister_netdevice_many_notify+0x1556/0x1ff0 net/core/dev.c:12218 ops_exit_rtnl_list net/core/net_namespace.c:186 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:247 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 page last free pid 5549 tgid 5549 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 __slab_free+0x2e7/0x390 mm/slub.c:5656 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4770 [inline] slab_alloc_node mm/slub.c:5068 [inline] __do_kmalloc_node mm/slub.c:5425 [inline] __kmalloc_noprof+0x3c3/0x7f0 mm/slub.c:5438 kmalloc_noprof include/linux/slab.h:960 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 security_inode_getattr+0x12f/0x330 security/security.c:2416 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:555 [inline] __se_sys_newfstat fs/stat.c:550 [inline] __x64_sys_newfstat+0xfc/0x200 fs/stat.c:550 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888076dfc380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076dfc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888076dfc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888076dfc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076dfc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.