From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (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 E501536DA04 for ; Fri, 25 Sep 2026 02:34:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790303661; cv=none; b=JThcLfCubkkqo5ZILWIgZy36+ZkIuhsVHP5zlG94vs49cMpoX0YY/qae3rBO8Sea26+eILkPZyfifYfBP4Z0MmZLAE6iMpXmzJXrzetSNPaHLG12mDD7yIm73QHHgnARpiJl/+f9KoMfPK5skxEdO+l2CkUsuEaKxHc2y7fd3JM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790303661; c=relaxed/simple; bh=zj3f6qwkqvWIUWZ4vffUnCaZ1C7pFH8GGmIRpILvJtI=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=h/gamUOHd/sn2cx5whO6NCtSbUNhna84z/S0yz1x7Auxiz5M3xZv/53ScvujJJW6rHZFgXIgEC+b3JxtGqSlw22Rc+267ZHgEo/1YrFlfrxvKujh6UkIMoIiDTepi71h6FKLxWC7U73nGA+Ad20n1/8OfbEyl305GZ0a4ks5l/E= 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=209.85.167.197 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-f197.google.com with SMTP id 5614622812f47-4a7de733fa9so961163b6e.3 for ; Thu, 24 Sep 2026 19:34:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790303658; x=1790908458; h=content-type:cc:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=7mfCntzFPrQsHd7pLgQcS6+abA6VY4yY58dlYvEW43s=; b=YmIiRHImvRyObhkkOz/Y5lUckDsLInODxM9TngK/pvWnbDlh8w0SP9g7ZM+oscGps2 GxbPrr9TZtV7EvFY+MynOn8pwlkAwi/aZApbSrcYNrMtf9eo9yc00YRO9ku8wBVkOXDw aBzsPv1ivciXo2/vUPiozFXnyj26rNf7fcHDX/V26wlF2e6HG/uAlpP/5c6mQNGANeHY izRRfN7zS6ElhN8fEXd63gILKyJ+BKSBve4yJdfuIxqCr4Mu1JwrlsyDEYx0rojNAOCG fwX9vTOG4+cGzs4rAqmSQS+8wRi0I8BO3dC6SvwSYgDOnpK/CizzFm6VKpV4JxDNjlNY qiIg== X-Forwarded-Encrypted: i=1; AKwUvBz/X7mFAyEW0zWVmMCJCfq5RnCwKdyHjOWd1vuz5gDuRg0gOIvc3OnIIhkJi7yn5RSstkwkQEie86Ta0gud@vger.kernel.org X-Gm-Message-State: AFuF++kvnrrnqUlxBu1U8dEcZb17amwn7W/r8//gGJs9DF593tnaT4RL rshDyw93pMFt6lu8xtifB5sCeNxqI09DE/Ga96JQckBiV/YglSIE9sRLAwY3fZq9vUgHGgQ6Xqy LxkLgeFk5dRWWcVCPcCO96UzGDmzElSGpHd4arZ4q2F5f7DO7Gl2i9Oad1tk= Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:16a1:b0:4d6:9283:1ded with SMTP id 5614622812f47-4d72ef5b96amr4144381b6e.59.1790303657893; Thu, 24 Sep 2026 19:34:17 -0700 (PDT) Date: Thu, 24 Sep 2026 19:34:17 -0700 In-Reply-To: <20260922121912.2258134-2-jack@suse.cz> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ab5dda9.80e1c6cc.1e8e5f.001f.GAE@google.com> Subject: [syzbot ci] Re: isofs: Fix handling of directories with tight blocks From: syzbot ci To: jack@suse.cz, linux-fsdevel@vger.kernel.org, matthias.goergens@gmail.com, scdbackup@gmx.net Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v1] isofs: Fix handling of directories with tight blocks https://lore.kernel.org/all/20260922121912.2258134-2-jack@suse.cz * [PATCH] isofs: Fix handling of directories with tight blocks and found the following issues: * INFO: task hung in d_alloc_parallel * INFO: task hung in lookup_slow Full report is available here: https://ci.syzbot.org/series/1c5e91af-d857-4245-95ce-5602d6c1fc78 *** INFO: task hung in d_alloc_parallel tree: vfs URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/vfs.git base: 061b90224ee6e3d51fcfd606d34a1c79365ea1b5 arch: amd64 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 config: https://ci.syzbot.org/builds/5fea1b08-98ff-4ff5-8b8d-d7bf6f5a222b/config syz repro: https://ci.syzbot.org/findings/9651a622-bc22-4db7-91ce-80075a40390b/syz_repro INFO: task syz.2.19:5860 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.19 state:D stack:28296 pid:5860 tgid:5858 ppid:5737 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 d_wait_lookup fs/dcache.c:2775 [inline] d_alloc_parallel+0xcdd/0x16b0 fs/dcache.c:2860 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_lookupat+0xe4/0x8c0 fs/namei.c:2812 do_o_path+0x9f/0x210 fs/namei.c:4980 path_openat+0x16c5/0x1da0 fs/namei.c:5002 do_file_open+0x23e/0x4a0 fs/namei.c:5038 do_sys_openat2+0x115/0x200 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1459 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: 0033:0x7f2c4d99e159 RSP: 002b:00007f2c4e86b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f2c4dc26090 RCX: 00007f2c4d99e159 RDX: 0000000000200002 RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f2c4da3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2c4dc26128 R14: 00007f2c4dc26090 R15: 00007fffbbb4ebb8 INFO: task syz.1.18:5866 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:28296 pid:5866 tgid:5862 ppid:5736 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 d_wait_lookup fs/dcache.c:2775 [inline] d_alloc_parallel+0xcdd/0x16b0 fs/dcache.c:2860 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_lookupat+0xe4/0x8c0 fs/namei.c:2812 do_o_path+0x9f/0x210 fs/namei.c:4980 path_openat+0x16c5/0x1da0 fs/namei.c:5002 do_file_open+0x23e/0x4a0 fs/namei.c:5038 do_sys_openat2+0x115/0x200 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1459 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: 0033:0x7f299799e159 RSP: 002b:00007f2996fdd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f2997c26090 RCX: 00007f299799e159 RDX: 0000000000200002 RSI: 0000200000000100 RDI: ffffff RDX: 0000000000200002 RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f2997a3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2997c26128 R14: 00007f2997c26090 R15: 00007ffc5b4deeb8 INFO: task syz.0.17:5867 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:28296 pid:5867 tgid:5864 ppid:5731 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 d_wait_lookup fs/dcache.c:2775 [inline] d_alloc_parallel+0xcdd/0x16b0 fs/dcache.c:2860 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_lookupat+0xe4/0x8c0 fs/namei.c:2812 do_o_path+0x9f/0x210 fs/namei.c:4980 path_openat+0x16c5/0x1da0 fs/namei.c:5002 do_file_open+0x23e/0x4a0 fs/namei.c:5038 do_sys_openat2+0x115/0x200 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1459 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: 0033:0x7f8d1299e159 RSP: 002b:00007f8d138b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8d12c26090 RCX: 00007f8d1299e159 RDX: 0000000000200002 RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f8d12a3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d12c26128 R14: 00007f8d12c26090 R15: 00007ffda1300988 Showing all locks held in the system: locks held by khungtaskd/36: 1, last CPU#1: #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by getty/5424: 2, on CPU#1: #0: ffff888172fc30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900034832e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz.2.19/5859: 1, last CPU#1: #0: ffff88811e2537c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2537c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.2.19/5860: 1, on CPU#1: #0: ffff88811e2537c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2537c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.1.18/5863: 2, last CPU#0: #0: ffff8881b087b7c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087b7c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 #1: ffffffff8eea5ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4392 locks held by syz.1.18/5866: 1, on CPU#1: #0: ffff8881b087b7c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087b7c0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.0.17/5865: 1, last CPU#0: #0: ffff88811e2532d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2532d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.0.17/5867: 1, on CPU#1: #0: ffff88811e2532d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2532d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.3.20/5989: 1, last CPU#1: #0: ffff88811e252de0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e252de0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.3.20/5990: 1, on CPU#0: #0: ffff88811e252de0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e252de0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.4.21/5992: 1, last CPU#0: #0: ffff8881b087b2d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087b2d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.4.21/5993: 1, on CPU#0: #0: ffff8881b087b2d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087b2d0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.5.22/5995: 1, last CPU#0: #0: ffff8881b087ade0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087ade0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.5.22/5996: 1, on CPU#0: #0: ffff8881b087ade0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087ade0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.8.25/6124: 1, last CPU#0: #0: ffff8881b087a8f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087a8f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.8.25/6125: 1, on CPU#1: #0: ffff8881b087a8f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087a8f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.7.24/6127: 1, last CPU#1: #0: ffff88811e2528f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2528f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.7.24/6130: 1, on CPU#1: #0: ffff88811e2528f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e2528f0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.6.23/6129: 1, last CPU#0: #0: ffff8881b087a400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087a400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.6.23/6131: 1, on CPU#0: #0: ffff8881b087a400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881b087a400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.9.26/6247: 2, last CPU#1: #0: ffff88811e252400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e252400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 #1: ffffffff8eea5ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4392 locks held by syz.9.26/6248: 1, on CPU#0: #0: ffff88811e252400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88811e252400 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.1.1095/8434: 1, last CPU#1: #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: find_lock_entries+0x12a/0xad0 mm/filemap.c:2188 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 36 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5989 Comm: syz.3.20 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:check_preemption_disabled+0x6/0xd0 lib/smp_processor_id.c:14 Code: c7 c6 60 91 6d 8c eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 <65> 8b 05 db 2d af 07 65 48 8b 0d ab 2d af 07 85 c9 74 0c 5b 41 5e RSP: 0018:ffffc9000273f3a8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffffff8260321f RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e4127e6 RDI: ffffffff8c6d9180 RBP: 0000000000000000 R08: ffffc9000273f567 R09: 1ffff920004e7eac R10: dffffc0000000000 R11: fffff520004e7ead R12: 0000000000000400 R13: 0000000000000800 R14: ffff8881694e8000 R15: 0000000000000022 FS: 00007f30a0bd66c0(0000) GS:ffff8882a8cd0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34263fff CR3: 00000001172fe000 CR4: 00000000000006f0 Call Trace: lockdep_hardirqs_off+0x57/0xd0 kernel/locking/lockdep.c:4555 trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104 lookup_bh_lru fs/buffer.c:1264 [inline] find_get_block_common+0x6f/0xe10 fs/buffer.c:1301 bdev_getblk+0x58/0x6e0 include/linux/gfp.h:-1 __bread_gfp+0x89/0x380 fs/buffer.c:1412 sb_bread include/linux/buffer_head.h:383 [inline] isofs_bread+0x1d9/0x270 fs/isofs/inode.c:1145 isofs_find_entry fs/isofs/namei.c:72 [inline] isofs_lookup+0x260/0xdc0 fs/isofs/namei.c:162 __lookup_slow+0x1fb/0x2f0 fs/namei.c:1919 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_lookupat+0xe4/0x8c0 fs/namei.c:2812 do_o_path+0x9f/0x210 fs/namei.c:4980 path_openat+0x16c5/0x1da0 fs/namei.c:5002 do_file_open+0x23e/0x4a0 fs/namei.c:5038 do_sys_openat2+0x115/0x200 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1459 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: 0033:0x7f309fd9e159 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:00007f30a0bd6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f30a0025fa0 RCX: 00007f309fd9e159 RDX: 0000000000200002 RSI: 00002000000000c0 RDI: ffffffffffffff9c RBP: 00007f309fe3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f30a0026038 R14: 00007f30a0025fa0 R15: 00007ffdb7dac4f8 *** INFO: task hung in lookup_slow tree: vfs URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/vfs.git base: 061b90224ee6e3d51fcfd606d34a1c79365ea1b5 arch: amd64 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 config: https://ci.syzbot.org/builds/5fea1b08-98ff-4ff5-8b8d-d7bf6f5a222b/config syz repro: https://ci.syzbot.org/findings/312b0012-93c1-4dd0-8aaa-a1f18531ccb7/syz_repro INFO: task syz.1.18:5813 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:28704 pid:5813 tgid:5811 ppid:5739 task:syz.1.18 state:D stack:28704 pid:5813 tgid:5811 ppid:5739 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 rwsem_down_read_slowpath+0x6d8/0x980 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x9c/0x330 kernel/locking/rwsem.c:1576 inode_lock_shared include/linux/fs.h:1039 [inline] lookup_slow+0x46/0x70 fs/namei.c:1935 walk_component fs/namei.c:2282 [inline] lookup_last fs/namei.c:2789 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2813 filename_lookup+0x265/0x5d0 fs/namei.c:2842 user_path_at+0x40/0x160 fs/namei.c:3641 do_mount fs/namespace.c:4178 [inline] __do_sys_mount fs/namespace.c:4395 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4372 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: 0033:0x7fbdcc59e159 RSP: 002b:00007fbdcbbfe028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fbdcc826090 RCX: 00007fbdcc59e159 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007fbdcc63506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbdcc826128 R14: 00007fbdcc826090 R15: 00007ffda8e823c8 INFO: task syz.2.19:5875 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.19 state:D stack:28808 pid:5875 tgid:5870 ppid:5740 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 rwsem_down_read_slowpath+0x6d8/0x980 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x9c/0x330 kernel/locking/rwsem.c:1576 inode_lock_shared include/linux/fs.h:1039 [inline] lookup_slow+0x46/0x70 fs/namei.c:1935 walk_component fs/namei.c:2282 [inline] lookup_last fs/namei.c:2789 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2813 filename_lookup+0x265/0x5d0 fs/namei.c:2842 user_path_at+0x40/0x160 fs/namei.c:3641 do_mount fs/namespace.c:4178 [inline] __do_sys_mount fs/namespace.c:4395 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4372 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: 0033:0x7fc452d9e159 RSP: 002b:00007fc4523dd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc453026090 RCX: 00007fc452d9e159 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007fc452e3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc453026128 R14: 00007fc453026090 R15: 00007ffc4eb10368 INFO: task syz.0.17:5876 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:28808 pid:5876 tgid:5873 ppid:5736 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 rwsem_down_read_slowpath+0x6d8/0x980 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x9c/0x330 kernel/locking/rwsem.c:1576 inode_lock_shared include/linux/fs.h:1039 [inline] lookup_slow+0x46/0x70 fs/namei.c:1935 walk_component fs/namei.c:2282 [inline] lookup_last fs/namei.c:2789 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2813 filename_lookup+0x265/0x5d0 fs/namei.c:2842 user_path_at+0x40/0x160 fs/namei.c:3641 do_mount fs/namespace.c:4178 [inline] __do_sys_mount fs/namespace.c:4395 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4372 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: 0033:0x7f615a79e159 RSP: 002b:00007f615b674028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f615aa26090 RCX: 00007f615a79e159 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f615a83506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f615aa26128 R14: 00007f615aa26090 R15: 00007ffc43a846c8 Showing all locks held in the system: locks held by khungtaskd/35: 1, last CPU#1: #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u10:6/1113: 2, on CPU#1: #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90006fb7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90006fb7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90006fb7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90006fb7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by getty/5423: 2, on CPU#1: #0: ffff888175c4b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz.1.18/5812: 2, last CPU#1: #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 #1: ffffffff8eea5ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4392 locks held by syz.1.18/5813: 1, on CPU#0: #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a249b7c0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.2.19/5871: 1, last CPU#0: #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.2.19/5875: 1, on CPU#1: #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a249b2d0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.0.17/5874: 1, last CPU#1: #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.0.17/5876: 1, on CPU#1: #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881189eb7c0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.3.20/5940: 1, last CPU#1: #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.3.20/5941: 1, on CPU#0: #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881189eb2d0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.5.22/6003: 1, last CPU#0: #0: ffff8881a249ade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a249ade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a249ade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a249ade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.5.22/6004: 1, on CPU#0: #0: ffff8881a249ade0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a249ade0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.4.21/6006: 1, last CPU#1: #0: ffff8881189eade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881189eade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881189eade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881189eade0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.4.21/6007: 1, on CPU#0: #0: ffff8881189eade0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881189eade0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.6.23/6053: 2, last CPU#0: #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 #1: ffffffff8eea5ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4392 locks held by syz.6.23/6057: 1, on CPU#1: #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a249a8f0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.7.24/6135: 1, last CPU#0: #0: ffff8881a249a400 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a249a400 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a249a400 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a249a400 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.7.24/6136: 1, on CPU#1: #0: ffff8881a249a400 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a249a400 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.8.25/6138: 1, last CPU#0: #0: ffff8881a2499f10 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881a2499f10 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881a2499f10 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881a2499f10 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.8.25/6139: 1, on CPU#0: #0: ffff8881a2499f10 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881a2499f10 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.9.26/6183: 1, last CPU#1: #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101 locks held by syz.9.26/6184: 1, on CPU#0: #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8881189ea8f0 (&type->i_mutex_dir_key#9){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.1.815/8671: 1, last CPU#0: #0: ffff88810ecf03b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline] #0: ffff88810ecf03b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323 locks held by syz.2.816/8673: 1, on CPU#1: #0: ffffffff8f4f0ed8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8f4f0ed8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8f4f0ed8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8f4f0ed8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_mount_permission+0x2b5/0x9e0 security/tomoyo/mount.c:238 locks held by modprobe/8675: 1, last CPU#1: #0: ffff88817439f678 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline] #0: ffff88817439f678 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6138 Comm: syz.8.25 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0xa0 kernel/kcov.c:316 Code: 74 0a 18 48 89 44 0a 20 c3 cc cc cc cc cc 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 18 1e cd 11 65 48 8b 15 18 1e RSP: 0018:ffffc900043df9b8 EFLAGS: 00000246 RAX: f8f8f8f8f8f8f8f8 RBX: ffff8881a2499dd0 RCX: ffff88816b385a00 RDX: 0000000000000000 RSI: 0000000000000022 RDI: 0000000000000000 RBP: ffffc900043dfb30 R08: ffffc900043dfa07 R09: 1ffff9200087bf40 R10: dffffc0000000000 R11: fffff5200087bf41 R12: 1ffff9200087bf38 R13: dffffc0000000000 R14: 0000000000000022 R15: ffffc900043dfa00 FS: 00007f875414d6c0(0000) GS:ffff88818d6d0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd7861f440 CR3: 00000001beb7a000 CR4: 00000000000006f0 Call Trace: isofs_bread+0x15e/0x270 fs/isofs/inode.c:1143 isofs_find_entry fs/isofs/namei.c:72 [inline] isofs_lookup+0x260/0xdc0 fs/isofs/namei.c:162 lookup_one_qstr_excl+0x12d/0x360 fs/namei.c:1810 __start_dirop fs/namei.c:2920 [inline] start_dirop fs/namei.c:2942 [inline] filename_create+0x20e/0x370 fs/namei.c:5101 filename_mkdirat+0xd2/0x510 fs/namei.c:5445 __do_sys_mkdirat fs/namei.c:5473 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5470 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: 0033:0x7f875319e159 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:00007f875414d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8753425fa0 RCX: 00007f875319e159 RDX: 00000000000001ff RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f875323506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8753426038 R14: 00007f8753425fa0 R15: 00007ffc77a2a958 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com. To test a fix for this bug, please reply with `#syz test` (on a separate line) and attach the patch to the email. Notes: - The patch will be applied on top of the tested series (as an incremental fix). - To test a new version of the whole series, please send it directly to syzbot@lists.linux.dev. - Arguments like custom git repos and branches are not supported.