From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (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 0792B342CBA for ; Wed, 26 Aug 2026 04:13:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787717607; cv=none; b=WVHmx7X2dSEvqpA45c3eZpSVVz5SgjwIRM2lGfd3n7ZOpxdczjOilRMJyofnI2rK/XUYba1wNJUYd3HfESyc3HXadQhvvYrTMIOCD/xx9wbdP5b4noLRkkDgCaAvuQs6bV0WpYNnYuLcyeSL0Mg1MF142J2SkQ/prW+ZlGf+lCE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787717607; c=relaxed/simple; bh=1OI7Hn2OtUsGj2g6wD2ncM/i6yJfXdGnkt+CXZRmuhI=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=oO9vYt2YyqBUzSeAEsvD78tZXpKvbJKyCRhR5GvDKpOJ9gCL4kp5azmwAPxkv8Ol5JxUSL+OTneN+z+6iPQaFe64jXxcs4syvb0b5tYd+fVoNw9PZffFEMCkb4nk7vrh+neRU62mwtV23bzmc8CnKqI+5TfygMxIwG8NAisvZ24= 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=209.85.167.207 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-oi1-f207.google.com with SMTP id 5614622812f47-4b28d7ffab1so1230437b6e.1 for ; Tue, 25 Aug 2026 21:13:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787717604; x=1788322404; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=dH8LMgq2lClqzertM4aEA6NkNerUxL8wmZ/eyeuD01A=; b=Pj2WQVa2AJe9T/FnOeTYgh/uVYksnGHjuDu15MhXQHVbUtWF9Ld8C8QfXH+lma4rLD hnL8YO7ozCIN/LUNU1jtpitSyH08vTjgo0c61POCXrV+rQuSS7W9lUqvRCStaj0QaAZJ NgjE41Fa7xRe+FavsbqoY11QCPA+9w4TqzU//r7Ibx8oLfGV69PXkfrIYyr6Ox+LWcGP zJ2LPvp+DgxdJYuNNYL2I6PMzhxoStnUItXKZKOiJGncLolh+12VBTWdZgVvLD9VYzqi 41mV2jPXO57rRZcxCb+cU0iNwG6onPC2pvNw7flTUoXnZJWMOAKWcYgund8UVOcTd/Gc ns7g== X-Forwarded-Encrypted: i=1; AHgh+RpYxsdofdWwb95QFzOMpYwiV+MlolLIpQQq0BsCePHtEAhrnICBR/g9XEd7xNGBRhHFt773GkBX3MwE53k=@vger.kernel.org X-Gm-Message-State: AFuF++k34pEl1dlWYAP+jUnfWeg3MdNmq4EjvorFnbXK5Z4wCbnc9BrF u1UOlS1yEhgruJ4wjjrv/dlymrXBH8/xJhhlf08iWrsbxHVeSTb5bpHvQHh/iJohRJvEj47zl9U HvswoQFQNqYfnj/P0U52sNav95tB3KivyWPCcoz5j0vxSJ0tqSvel6x/RbxU= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:6f93:b0:496:9ee:e538 with SMTP id 5614622812f47-4b3502886bemr9512518b6e.5.1787717604000; Tue, 25 Aug 2026 21:13:24 -0700 (PDT) Date: Tue, 25 Aug 2026 21:13:23 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a8e67e3.91706f20.ef82.0014.GAE@google.com> Subject: [syzbot] [fs?] possible deadlock in uvcg_frame_dw_max_video_frame_buffer_size_show From: syzbot To: a.hindborg@kernel.org, leitao@debian.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 818bebeb63dd drm/xe: Don't hand out the flat CCS storage a.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=133d1549580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8a263b38e64491d5 dashboard link: https://syzkaller.appspot.com/bug?extid=56ec747ac8dd3a35cdeb compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/987f25555283/disk-818bebeb.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0b351e1afd72/vmlinux-818bebeb.xz kernel image: https://storage.googleapis.com/syzbot-assets/58f64cf2ad53/bzImage-818bebeb.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+56ec747ac8dd3a35cdeb@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.6.2659/15951 is trying to acquire lock: ffffffff8ef795e0 (gadget_subsys.su_mutex){+.+.}-{4:4}, at: uvcg_frame_dw_max_video_frame_buffer_size_show+0x6c/0x180 drivers/usb/gadget/function/uvc_configfs.c:2033 but task is already holding lock: ffff888040528a68 (&p->frag_sem){++++}-{4:4}, at: fill_read_buffer fs/configfs/file.c:66 [inline] ffff888040528a68 (&p->frag_sem){++++}-{4:4}, at: configfs_read_iter+0x1cf/0x620 fs/configfs/file.c:88 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->frag_sem){++++}-{4:4}: down_write_killable+0x4a/0x80 kernel/locking/rwsem.c:1643 configfs_rmdir+0x3b0/0x950 fs/configfs/dir.c:1534 vfs_rmdir+0x3e9/0x6b0 fs/namei.c:5515 filename_rmdir+0x292/0x520 fs/namei.c:5572 __do_sys_rmdir fs/namei.c:5595 [inline] __se_sys_rmdir+0x2e/0x140 fs/namei.c:5592 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&sb->s_type->i_mutex_key#27){++++}-{4:4}: down_write+0x3a/0x50 kernel/locking/rwsem.c:1631 inode_lock include/linux/fs.h:1025 [inline] configfs_depend_item_unlocked+0x153/0x420 fs/configfs/dir.c:1259 usbg_make_tpg+0x1f6/0x590 drivers/usb/gadget/function/f_tcm.c:1686 target_fabric_make_tpg+0xa8/0x6d0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x408/0x620 fs/namei.c:5410 filename_mkdirat+0x289/0x520 fs/namei.c:5443 __do_sys_mkdir fs/namei.c:5470 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5467 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&opts->dep_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 tcm_set_name+0x2b/0xd0 drivers/usb/gadget/function/f_tcm.c:2669 function_make+0x1a8/0x360 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x408/0x620 fs/namei.c:5410 filename_mkdirat+0x289/0x520 fs/namei.c:5443 __do_sys_mkdir fs/namei.c:5470 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5467 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (gadget_subsys.su_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5253 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 uvcg_frame_dw_max_video_frame_buffer_size_show+0x6c/0x180 drivers/usb/gadget/function/uvc_configfs.c:2033 fill_read_buffer fs/configfs/file.c:68 [inline] configfs_read_iter+0x2ba/0x620 fs/configfs/file.c:88 __kernel_read+0x4d3/0x970 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+0x45d/0x8a0 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x521/0xa10 security/integrity/ima/ima_api.c:300 process_measurement+0x1282/0x1c20 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+0x148a/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+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: gadget_subsys.su_mutex --> &sb->s_type->i_mutex_key#27 --> &p->frag_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&p->frag_sem); lock(&sb->s_type->i_mutex_key#27); lock(&p->frag_sem); lock(gadget_subsys.su_mutex); *** DEADLOCK *** locks held by syz.6.2659/15951: 3, last CPU#0: #0: ffff88803b82a658 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x7e0/0x1c20 security/integrity/ima/ima_main.c:319 #1: ffff888033ff3078 (&buffer->mutex){+.+.}-{4:4}, at: configfs_read_iter+0x73/0x620 fs/configfs/file.c:86 #2: ffff888040528a68 (&p->frag_sem){++++}-{4:4}, at: fill_read_buffer fs/configfs/file.c:66 [inline] #2: ffff888040528a68 (&p->frag_sem){++++}-{4:4}, at: configfs_read_iter+0x1cf/0x620 fs/configfs/file.c:88 stack backtrace: CPU: 0 UID: 0 PID: 15951 Comm: syz.6.2659 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP 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_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5253 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 uvcg_frame_dw_max_video_frame_buffer_size_show+0x6c/0x180 drivers/usb/gadget/function/uvc_configfs.c:2033 fill_read_buffer fs/configfs/file.c:68 [inline] configfs_read_iter+0x2ba/0x620 fs/configfs/file.c:88 __kernel_read+0x4d3/0x970 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+0x45d/0x8a0 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x521/0xa10 security/integrity/ima/ima_api.c:300 process_measurement+0x1282/0x1c20 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+0x148a/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+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae2ac1e0d9 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:00007fae28a11028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fae2aea6270 RCX: 00007fae2ac1e0d9 RDX: 0000000000000082 RSI: 0000000000000000 RDI: 0000200000000640 RBP: 00007fae2acb5024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fae2aea6308 R14: 00007fae2aea6270 R15: 00007ffdeb312178 --- 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