From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47074C83F26 for ; Mon, 28 Jul 2025 23:27:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B48A96B0088; Mon, 28 Jul 2025 19:27:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AF9976B0089; Mon, 28 Jul 2025 19:27:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A0F446B008A; Mon, 28 Jul 2025 19:27:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 8E4FF6B0088 for ; Mon, 28 Jul 2025 19:27:37 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 1F10CB944B for ; Mon, 28 Jul 2025 23:27:37 +0000 (UTC) X-FDA: 83715262554.03.0A6BD4A Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) by imf01.hostedemail.com (Postfix) with ESMTP id 6501440002 for ; Mon, 28 Jul 2025 23:27:35 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of 3ZgeIaAkbAN8TZaLBMMFSBQQJE.HPPHMFVTFSDPOUFOU.DPN@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com designates 209.85.166.208 as permitted sender) smtp.mailfrom=3ZgeIaAkbAN8TZaLBMMFSBQQJE.HPPHMFVTFSDPOUFOU.DPN@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=appspotmail.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1753745255; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding:in-reply-to: references; bh=hD5qCfVKkQkP0GM9gjEI3OSR5qeZPRyjb0lH1o5UpyI=; b=5lVMbHPXubVDoJXFVsjz8oVZrXONborUnjH+i1Kn3WemgjhYqXeD24n1PaJ99AG+/hjsk3 Fr/nOWY1q55OcSU3TkRs1qRxVKUggl6iNFEoyf3Fl4wiiBaTRHFVDNZ8OLDSyMHXtz3Whx Hap5HUfQ4DvPhhVkblYoVOsn0QeY0yM= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1753745255; a=rsa-sha256; cv=none; b=oSbtRglc9qcBGfI03KEVncbOCV53fAdV7cf9TiU6vh11Kzfvx3l0ULQ7X2IZXZK/BqNb5p eXsYmcW7n3JbVKCd4fKMvbHVPlcIUXgXtzShOC+JWhcUeg6FRwTotNJ0WYvowja9V/Jfwf dqv7518MX92HteXUY+F2zzKhCK7aHZM= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of 3ZgeIaAkbAN8TZaLBMMFSBQQJE.HPPHMFVTFSDPOUFOU.DPN@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com designates 209.85.166.208 as permitted sender) smtp.mailfrom=3ZgeIaAkbAN8TZaLBMMFSBQQJE.HPPHMFVTFSDPOUFOU.DPN@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=appspotmail.com (policy=none) Received: by mail-il1-f208.google.com with SMTP id e9e14a558f8ab-3e2c230d55dso51774995ab.2 for ; Mon, 28 Jul 2025 16:27:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753745254; x=1754350054; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=hD5qCfVKkQkP0GM9gjEI3OSR5qeZPRyjb0lH1o5UpyI=; b=FXUQu8V0OO0rVz51hwXcPWjMUzII6njg9q9Xdrfr3Mz0ijutPRmzqLvoAC/9qJHiny 3MvSzj8NJbtDoXPoBO0GX4abNAJc7vdfKUHdm4T57zRHIO5USqkQzspBV6t6aG4WFlm4 icv/Fur3cusPvRCsZ49nZq4nao+DdgSaPdvzdTHgS/zhw7ua7XpqAPd0pLXM5n2/tmR4 vbbVPO5wYGgl/t4nT0qeHzg/1kyuqWNqKRwuC5hyRh4i8JVdQY5DNJJZlYrxb9iszgp0 OpW/GwA6T34yUEa0gcE/UsG1G0N7CusEeO121RHqug3VUpdxAW5qRql9Jyz4h09J0mRq 9z/g== X-Forwarded-Encrypted: i=1; AJvYcCWdMYuzJ96YTUzbtvj79ErHrkcjWOsMAyl2l3jC6cMU27Z5NioYx7KFd+WAIGOM8ouOxEKZvoDynw==@kvack.org X-Gm-Message-State: AOJu0Yzn2hiT27K/9doIyDp3BYaZZVW/8V3SnvcOLNzu/MfeDzKAwA6H A7NKWeU1QyGAkP4VDf3UEqIIBtMkK96KFcH4XfyL+LIanY1XvKOXo4fVJv5VCpSvrNN1rCx189P +dRsyJui4+hnRhLp74d7JrvgnK+DSeCNfCLAp0Dn5o92qVwP/rcjxzM9UJ20= X-Google-Smtp-Source: AGHT+IHhXsEtfhTdqeefK2LawH5pZPtCQBSt2iG1H1PkCV5Lvfs4Sxa6MHL1kQNWFql45es2q2U05rl9bb4G0SYRFz0BF0DKd39p MIME-Version: 1.0 X-Received: by 2002:a92:c26e:0:b0:3e2:9caa:7cbb with SMTP id e9e14a558f8ab-3e3c527d214mr185025325ab.9.1753745254372; Mon, 28 Jul 2025 16:27:34 -0700 (PDT) Date: Mon, 28 Jul 2025 16:27:34 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68880766.050a0220.3cc461.000f.GAE@google.com> Subject: [syzbot] [kernfs?] [mm?] INFO: rcu detected stall in kernfs_fop_open (7) From: syzbot To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, tj@kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 6501440002 X-Stat-Signature: i1ic51uidoutyf1z9d9pamz88ecsxu1i X-Rspam-User: X-HE-Tag: 1753745255-526655 X-HE-Meta: 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 3mD8Jjya 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 FqIWKbxv DsSVJj1URIelUbQukdhETkm2w2ZODYi71R2g8s4aTkXXaJD+UbOLGcLqPLOmt4UEgyqTy4MYkhCG7eGG9as7fTFCAK9k5ngb/e/9sSoAYBkpdKkSqrYEO5dYEPo0yI3lemHNxP2XZ4wvjwTNDmnQN+QX/b5//Ct+ocTUp0lVkhTth8rEAZr6SQ2Uc8dhegOH2dyAjMRoNt9488POOl4ermsJEXV+jE2u/qgfQUjcKkClzRQQmUUYrnMFQn3RqzAZNnnj5Aq517hBM3xWsJec0D6Tj0LH07c0b3Dk3b1c7Q+oE771gX6WVIX+33kwAfpHLuwHgdrr4gff6g4ISJoTUPVXKxP/nzLRWaCmkh3xzB0nVRhwaKy9SYfcJ9WGnwmpk5z/DOW5FYxrH4c6QbnTP6oJR/emnf2IC55TAFr3ESs= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, syzbot found the following issue on: HEAD commit: 25fae0b93d1d Merge tag 'drm-fixes-2025-07-24' of https://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11a5bfd4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a4bcc0a11b3192be dashboard link: https://syzkaller.appspot.com/bug?extid=19d01f6082ec61dd45b2 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1656bb82580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15a070a2580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/26a32daab34b/disk-25fae0b9.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/44b0af5dddac/vmlinux-25fae0b9.xz kernel image: https://storage.googleapis.com/syzbot-assets/0687991f0381/bzImage-25fae0b9.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+19d01f6082ec61dd45b2@syzkaller.appspotmail.com rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=375c/1/0x4000000000000000 softirq=18409/18409 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5512/1:b..l rcu: (detected by 1, t=10502 jiffies, g=12441, q=623 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5955 Comm: udevd Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:__lock_acquire+0xa4f/0xd20 kernel/locking/lockdep.c:5237 Code: e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 8c 02 00 00 41 8b 46 20 25 ff 1f 00 00 48 0f a3 05 f1 3a 09 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 f0 82 48 93 eb 40 83 3d 38 ca RSP: 0018:ffffc90000007b70 EFLAGS: 00000003 RAX: 000000000000006d RBX: 0000000000000001 RCX: 00000000ab2b819a RDX: 00000000001bf57d RSI: 00000000f5f6d907 RDI: ffff888061b90000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ae7962 R10: dffffc0000000000 R11: fffffbfff1f43b9f R12: 000000000000006e R13: ffff888061b90af0 R14: ffff888061b90b18 R15: 4d4df099ab2b819a FS: 00007fe3e1610880(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f509ec85f98 CR3: 0000000032c5c000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_acquire+0xc9/0x360 kernel/locking/lockdep.c:5867 Code: 01 11 85 c0 0f 85 eb 00 00 00 65 48 8b 04 25 08 d0 9f 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c <8f> 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 20 RSP: 0018:ffffc90003197290 EFLAGS: 00000246 RAX: ffff888061b90000 RBX: 0000000000000000 RCX: 0d0c881f9d5e1900 RDX: 0000000000000000 RSI: ffffffff8172ab02 RDI: 1ffffffff1c27e1c RBP: ffffffff8172aae5 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90003197458 R11: ffffffff81acfe40 R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x397/0xca0 fs/kernfs/file.c:623 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3896 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4055 do_filp_open+0x1fa/0x410 fs/namei.c:4082 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe3e0ea7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe447dd8f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe3e1610880 RCX: 00007fe3e0ea7407 RDX: 0000000000080000 RSI: 00007ffe447dda70 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000556b9eca17f5 R13: 0000556b9eca17f5 R14: 0000000000000001 R15: 0000556b9ecbc140 task:dhcpcd state:R running task stack:21384 pid:5512 tgid:5512 ppid:5511 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6966 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6990 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:108 sock_def_readable+0x1fb/0x550 net/core/sock.c:3583 unix_dgram_sendmsg+0xd78/0x17d0 net/unix/af_unix.c:2236 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1131 do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f810cb46407 RSP: 002b:00007ffd0761b7f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f810cabc740 RCX: 00007f810cb46407 RDX: 0000000000000002 RSI: 00007ffd0761b890 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000b R13: 00007f810cabc6c8 R14: 0000000000000000 R15: 00007ffd0762b9a0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g12441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=4027 rcu: rcu_preempt kthread starved for 10502 jiffies! g12441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- 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 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. 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