From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 246ED4BD0F2 for ; Mon, 19 Oct 2026 11:41:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792410083; cv=none; b=S7GT/7Rmlmf1GIAdtheZq61TSNwQ/aa3nG+iyk8SpOXNg5savD8UMChvnY2hcMkmcEdK9HozC033/2jU+lZksFhhyC3t5KPxkQczq6egR94qSiBfcUKGJfe51kWHnUM2EBWvAxTkiKuoVIzBOYHrO7FGm8DtdM1PBq2f2eJK8ks= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792410083; c=relaxed/simple; bh=zEJVgjcBGbrqH08I+qznBHmXlJCeMYko7gMge74Am9E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XHIt9qrH6+V0IxUeEv6vcRj/cCjUVMVscggWPY8/F7fO5rxUeSJNEL7XZqt8Z8K6gH4JLgVpcEYFJwLI4mfTegqvvWecHiQV8aWuiMUewNNvPbxv04cleNdYQygMyKCveXkjvPkIGMGO79WK5DYqqas2gOdKbAXE6YvaldVqOL8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=U6XYO5E7; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U6XYO5E7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1792410079; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8DxTawxVsBVMU+eNgJ4WRFaRIuf1HoW5qX8Tt2MpppQ=; b=U6XYO5E7niZYc71N4CXCcUQuhZsWku9DAegLVNvGYuHUadH5iOtrYpRxkBe708YJ9EmTXw nmx2YoJzAbOybW7kSwS6ruuW5g3bqItnbpFFEYHPu6uyVKZyHkABBCoThPh98rzE4pyVXg xqHeLc4pTf5DhRLT01o2EjFHPhhv38Q= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-207-2s4ju_6yNseowZAkziHcPg-1; Mon, 19 Oct 2026 11:41:15 +0000 X-MC-Unique: 2s4ju_6yNseowZAkziHcPg-1 X-Mimecast-MFC-AGG-ID: 2s4ju_6yNseowZAkziHcPg_1792410073 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E5B051955F45; Mon, 19 Oct 2026 11:41:12 +0000 (UTC) Received: from onestero-thinkpadp1gen7.tpbc.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 5089B18002B1; Mon, 19 Oct 2026 11:41:06 +0000 (UTC) Received: by onestero-thinkpadp1gen7.tpbc.csb (nbSMTP-1.00) for uid 13628 oleg@redhat.com; Mon, 19 Oct 2026 13:41:12 +0200 (CEST) Date: Mon, 19 Oct 2026 13:41:05 +0200 From: Oleg Nesterov To: kernel test robot Cc: oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, Joel Granados , linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, wireguard@lists.zx2c4.com, achender@kernel.org Subject: Re: [linus:master] [sysctl] 8d75c338f0: BUG:KASAN:slab-use-after-free_in_touch_wq_lockdep_map Message-ID: References: <202610190310.9737b2e3-lkp@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202610190310.9737b2e3-lkp@intel.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 10/19, kernel test robot wrote: > > > Hello, > > kernel test robot noticed "BUG:KASAN:slab-use-after-free_in_touch_wq_lockdep_map" on: > > commit: 8d75c338f0bcecaa6c9af67f86c176b67b6acf3e ("sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master I don't think that commit could cause such a problem. Please re-check. Oleg. > [test failed on linux-next/master b810335a0699d1810683796b0e3ffe8827ddfe6c] > > in testcase: boot > > config: x86_64-randconfig-2300-20261014 > compiler: gcc-14 > test machine: qemu-system-x86_64 -enable-kvm -cpu Haswell-noTSX,enforce -smp 4 -m 16G > > (please refer to attached dmesg/kmsg for entire log/backtrace) > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags > | Reported-by: kernel test robot > | Closes: https://lore.kernel.org/oe-lkp/202610190310.9737b2e3-lkp@intel.com > > > [ 35.688893][ T1] BUG: KASAN: slab-use-after-free in touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] Read of size 8 at addr ffff8881259a2968 by task swapper/0/1 > [ 35.688893][ T1] > [ 35.688893][ T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.2.0-rc2-00010-g8d75c338f0bc #1 PREEMPT > [ 35.688893][ T1] Call Trace: > [ 35.688893][ T1] > [ 35.688893][ T1] dump_stack_lvl (dump_stack.c:94 dump_stack.c:120) > [ 35.688893][ T1] ? touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] print_address_description+0x51/0x300 > [ 35.688893][ T1] ? rcu_is_watching (rcu/tree.c:753 (discriminator 3)) > [ 35.688893][ T1] ? touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] print_report (kasan/report.c:482) > [ 35.688893][ T1] ? kmem_cache_debug_flags (slab.h:503) > [ 35.688893][ T1] ? fixup_red_left (slub.c:250) > [ 35.688893][ T1] ? touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] kasan_report (kasan/report.c:595) > [ 35.688893][ T1] ? touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] touch_wq_lockdep_map (workqueue.c:4031 (discriminator 1)) > [ 35.688893][ T1] __flush_workqueue (workqueue.c:4079) > [ 35.688893][ T1] ? xa_load (xarray.c:1621) > [ 35.688893][ T1] ? tracer_preempt_on (trace/trace_irqsoff.c:686 (discriminator 1)) > [ 35.688893][ T1] ? preempt_count_sub (sched/core.c:6019) > [ 35.688893][ T1] ? rcu_is_watching (rcu/tree.c:753 (discriminator 3)) > [ 35.688893][ T1] ? preempt_count_sub (sched/core.c:6019) > [ 35.688893][ T1] ? touch_wq_lockdep_map (workqueue.c:4043) > [ 35.688893][ T1] ? __up_write (locking/rwsem.c:1422 (discriminator 4)) > [ 35.688893][ T1] rds_ib_init (rds/ib.c:618) > [ 35.688893][ T1] rds_rdma_init (rds/rdma_transport.c:300) > [ 35.688893][ T1] ? rds_init (af_rds.c:?) > [ 35.688893][ T1] ? __raw_spin_unlock_irqrestore (linux/spinlock_api_smp.h:179 (discriminator 4)) > [ 35.688893][ T1] ? add_device_randomness (linux/spinlock.h:408 char/random.c:936) > [ 35.688893][ T1] ? random_get_entropy (x86/include/asm/timex.h:11) > [ 35.688893][ T1] ? sctp_diag_init (diag.c:?) > [ 35.688893][ T1] ? rds_init (rds/af_rds.c:977) > [ 35.688893][ T1] ? rcu_is_watching (rcu/tree.c:753 (discriminator 3)) > [ 35.688893][ T1] ? rds_init (af_rds.c:?) > [ 35.688893][ T1] do_one_initcall (main.c:1347) > [ 35.688893][ T1] ? trace_initcall_finish_cb (main.c:1289 (discriminator 1)) > [ 35.688893][ T1] ? __kmalloc_noprof (slub.c:5363 slub.c:5387) > [ 35.688893][ T1] ? do_initcalls (linux/slab.h:973 linux/slab.h:1290 main.c:1418) > [ 35.688893][ T1] do_initcalls (main.c:1409 (discriminator 1) main.c:1425 (discriminator 1)) > [ 35.688893][ T1] kernel_init_freeable (main.c:1445 main.c:1658) > [ 35.688893][ T1] ? rest_init (main.c:717) > [ 35.688893][ T1] kernel_init (main.c:1548) > [ 35.688893][ T1] ? rest_init (main.c:717) > [ 35.688893][ T1] ret_from_fork (x86/kernel/process.c:158) > [ 35.688893][ T1] ? exit_thread (x86/kernel/process.c:138) > [ 35.688893][ T1] ? __switch_to (x86/kernel/process_64.c:674) > [ 35.688893][ T1] ? rest_init (main.c:717) > [ 35.688893][ T1] ret_from_fork_asm (x86/entry/entry_64.S:245) > [ 35.688893][ T1] > [ 35.688893][ T1] > [ 35.688893][ T1] Allocated by task 1 on cpu 1 at 35.661878s: > [ 35.688893][ T1] stack_trace_save (stacktrace.c:122 (discriminator 1)) > [ 35.688893][ T1] kasan_save_stack (kasan/common.c:57) > [ 35.688893][ T1] kasan_save_track (kasan/common.c:78) > [ 35.688893][ T1] __kasan_kmalloc (kasan/common.c:415) > [ 35.688893][ T1] __kmalloc_noprof (linux/kasan.h:263 slub.c:5362 slub.c:5387) > [ 35.688893][ T1] __alloc_workqueue (workqueue.c:5827) > [ 35.688893][ T1] alloc_workqueue_va (workqueue.c:5946) > [ 35.688893][ T1] alloc_workqueue_noprof (workqueue.c:5962) > [ 35.688893][ T1] rds_threads_init (rds/threads.c:259 (discriminator 2)) > [ 35.688893][ T1] rds_init (rds/af_rds.c:961) > [ 35.688893][ T1] do_one_initcall (main.c:1347) > [ 35.688893][ T1] do_initcalls (main.c:1409 (discriminator 1) main.c:1425 (discriminator 1)) > [ 35.688893][ T1] kernel_init_freeable (main.c:1445 main.c:1658) > [ 35.688893][ T1] kernel_init (main.c:1548) > [ 35.688893][ T1] ret_from_fork (x86/kernel/process.c:158) > [ 35.688893][ T1] ret_from_fork_asm (x86/entry/entry_64.S:245) > [ 35.688893][ T1] > [ 35.688893][ T1] Freed by task 0 on cpu 3 at 35.674112s: > [ 35.688893][ T1] stack_trace_save (stacktrace.c:122 (discriminator 1)) > [ 35.688893][ T1] kasan_save_stack (kasan/common.c:57) > [ 35.688893][ T1] kasan_save_track (kasan/common.c:78) > [ 35.688893][ T1] kasan_save_free_info (kasan/generic.c:584) > [ 35.688893][ T1] __kasan_slab_free (kasan/common.c:285) > [ 35.688893][ T1] kfree (linux/kasan.h:235 slub.c:2705 slub.c:6405 slub.c:6720) > [ 35.688893][ T1] rcu_do_batch (rcu/tree.c:2645) > [ 35.688893][ T1] rcu_core (rcu/tree.c:2897) > [ 35.688893][ T1] handle_softirqs (softirq.c:622) > [ 35.688893][ T1] __irq_exit_rcu (softirq.c:496 softirq.c:735) > [ 35.688893][ T1] irq_exit_rcu (softirq.c:752) > [ 35.688893][ T1] sysvec_apic_timer_interrupt (x86/kernel/apic/apic.c:1062 (discriminator 35) x86/kernel/apic/apic.c:1062 (discriminator 35)) > [ 35.688893][ T1] asm_sysvec_apic_timer_interrupt (x86/include/asm/idtentry.h:546) > [ 35.688893][ T1] > [ 35.688893][ T1] Last potentially related work creation: > [ 35.688893][ T1] stack_trace_save (stacktrace.c:122 (discriminator 1)) > [ 35.688893][ T1] kasan_save_stack (kasan/common.c:57) > [ 35.688893][ T1] kasan_record_aux_stack (kasan/generic.c:556) > [ 35.688893][ T1] __call_rcu_common+0xe6/0x480 > [ 35.688893][ T1] kthread_worker_fn (kthread.c:1025) > [ 35.688893][ T1] kthread (kthread.c:436) > [ 35.688893][ T1] ret_from_fork (x86/kernel/process.c:158) > [ 35.688893][ T1] ret_from_fork_asm (x86/entry/entry_64.S:245) > [ 35.688893][ T1] > [ 35.688893][ T1] The buggy address belongs to the object at ffff8881259a2800 > [ 35.688893][ T1] which belongs to the cache kmalloc-1k of size 1024 > [ 35.688893][ T1] The buggy address belongs to the object at ffff8881259a2800 > [ 35.688893][ T1] which belongs to the cache kmalloc-1k of size 1024 > [ 35.688893][ T1] The buggy address belongs to the object at ffff8881259a2800 > [ 35.688893][ T1] which belongs to the cache kmalloc-1k of size 1024 > [ 35.688893][ T1] The buggy address is located 360 bytes inside of > [ 35.688893][ T1] freed 1024-byte region [ffff8881259a2800, ffff8881259a2c00) > [ 35.688893][ T1] The buggy address is located 360 bytes inside of > [ 35.688893][ T1] freed 1024-byte region [ffff8881259a2800, ffff8881259a2c00) > [ 35.688893][ T1] The buggy address is located 360 bytes inside of > [ 35.688893][ T1] freed 1024-byte region [ffff8881259a2800, ffff8881259a2c00) > [ 35.688893][ T1] > [ 35.688893][ T1] The buggy address belongs to the physical page: > [ 35.688893][ T1] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1259a0 > [ 35.688893][ T1] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 > [ 35.688893][ T1] flags: 0x4000000000000040(head|zone=2) > [ 35.688893][ T1] page_type: f5(slab) > [ 35.688893][ T1] raw: 4000000000000040 ffff888100042dc0 dead000000000100 dead000000000122 > [ 35.688893][ T1] raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 > [ 35.688893][ T1] head: 4000000000000040 ffff888100042dc0 dead000000000100 dead000000000122 > [ 35.688893][ T1] head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 > [ 35.688893][ T1] head: 4000000000000003 ffffea0004966801 00000000ffffffff 00000000ffffffff > [ 35.688893][ T1] head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 > [ 35.688893][ T1] page dumped because: kasan: bad access detected > [ 35.688893][ T1] > [ 35.688893][ T1] Memory state around the buggy address: > [ 35.688893][ T1] ffff8881259a2800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 35.688893][ T1] ffff8881259a2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 35.688893][ T1] >ffff8881259a2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 35.688893][ T1] ^ > [ 35.688893][ T1] ffff8881259a2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 35.688893][ T1] ffff8881259a2a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 35.688893][ T1] ================================================================== > [ 35.984299][ T1] Disabling lock debugging due to kernel taint > [ 35.987548][ T1] Oops: general protection fault, probably for non-canonical address 0xe0a07c0ec0000008: 0000 [#1] SMP KASAN > [ 35.988482][ T1] KASAN: maybe wild-memory-access in range [0x0504007600000040-0x0504007600000047] > [ 35.988482][ T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Tainted: G B 7.2.0-rc2-00010-g8d75c338f0bc #1 PREEMPT > [ 35.988482][ T1] Tainted: [B]=BAD_PAGE > [ 35.988482][ T1] RIP: 0010:do_raw_spin_lock (locking/spinlock_debug.c:86 (discriminator 2) locking/spinlock_debug.c:115 (discriminator 2)) > [ 35.988482][ T1] Code: 3b 58 81 49 8d 14 04 c7 02 f1 f1 f1 f1 c7 42 04 04 f3 f3 f3 65 48 8b 15 f0 53 f7 08 48 89 54 24 60 31 d2 48 89 fa 48 c1 ea 03 <8a> 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 09 84 d2 74 05 e8 39 > All code > ======== > 0: 3b 58 81 cmp -0x7f(%rax),%ebx > 3: 49 8d 14 04 lea (%r12,%rax,1),%rdx > 7: c7 02 f1 f1 f1 f1 movl $0xf1f1f1f1,(%rdx) > d: c7 42 04 04 f3 f3 f3 movl $0xf3f3f304,0x4(%rdx) > 14: 65 48 8b 15 f0 53 f7 mov %gs:0x8f753f0(%rip),%rdx # 0x8f7540c > 1b: 08 > 1c: 48 89 54 24 60 mov %rdx,0x60(%rsp) > 21: 31 d2 xor %edx,%edx > 23: 48 89 fa mov %rdi,%rdx > 26: 48 c1 ea 03 shr $0x3,%rdx > 2a:* 8a 14 02 mov (%rdx,%rax,1),%dl <-- trapping instruction > 2d: 48 89 f8 mov %rdi,%rax > 30: 83 e0 07 and $0x7,%eax > > > The kernel config and materials to reproduce are available at: > https://download.01.org/0day-ci/archive/20261019/202610190310.9737b2e3-lkp@intel.com > > > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki > >