From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f205.google.com (mail-oi1-f205.google.com [209.85.167.205]) (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 E1664339361 for ; Mon, 24 Aug 2026 10:57:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787569059; cv=none; b=RQ2IyNfdibVaqyLFGpFmE16J3F1lCnmt0xxWTOd/MZ998zI6qhmWqGh/hbXpVypF2hKb/nNa7fUhp618ao2h9glAwBymiM8vqTlldOwQFmr62+DwDxzpTMr367sy9yl1+N3YMmlz8Uht9EYkxM3IZ8aU4OGDYV2AKXPLb77vbXY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787569059; c=relaxed/simple; bh=TkVUHnCQYa2fic5cg4NUn4nlWui2yqEQ8ajSiA+s7/I=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=E4x/XQ6vYGTUW8wnrJxjLC1obXAI2MRemrybMNCHhJrxhcy35MW3+qfx1mEQCFh/L8V8Xw/v0yPzw7LQByZxzBGi1xUUv7UzM09MDr9PBFLZiXq+VjfeeVvissb5alXHaBDw7vxEZYfc/IffoariulxVlhmB9ai95r6BRnQKSmw= 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=209.85.167.205 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-f205.google.com with SMTP id 5614622812f47-4a41f46d629so6845645b6e.3 for ; Mon, 24 Aug 2026 03:57:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787569057; x=1788173857; 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=itKI7IK1rnj5HWWoEOykhgqDaQnq2vvRnEFXN+KJzFg=; b=cJ31Tx3wyuxSIRQdfnhG+Y14+4gP6sid9GZ0fZWd0mq1Fd78z6V8uP5tYnMo13nLMu FiGdOIMVN/tcl+y5VAk+jw7JTuDpWAdGg6Yt2HXlVDj8yLPh74JUzcoAdQCmOMq/xTqA EoKI8pcQwRzcDvjB+DVRhnipFu7jF22f9U6SzySCvPbmb9wVS1+YU4gatacIiQauoSHk z0tJYG1+YjW7poBvnJLxcw4I+6un0muU441z3xj3dvlk4+TBvQY51BHPGD3o8xOYw0mb b7N1evSuzyet0gtuaC3xJ5C+X3vwwrrT6YK1Tu3FuMOjRIwPgPSZeHTAzkBVX6+2ywNq vQTg== X-Gm-Message-State: AFuF++nNAmO+6PqRFf0e/4cQqIopvVVRJh9wQTz8N5KUcan8zJIQuO1k Bfb1ZvnoFnxT0UTGDjtACKsHEBycUmo9boR8WOHJhC4wUcYgAduVk4QTZiiYQiTZbEp1KwhF7Dz Vh9JNwCqRnuJNh2WVYX/fUoYdJv2ehiJLV208a7/OlMfB5mTDXSAF5rZnFDU5/A== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:4f4f:b0:4b2:e95f:380d with SMTP id 5614622812f47-4b2ef1f94a0mr26160496b6e.6.1787569056759; Mon, 24 Aug 2026 03:57:36 -0700 (PDT) Date: Mon, 24 Aug 2026 03:57:36 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a8c23a0.dbb3a75c.7844.0001.GAE@google.com> Subject: [syzbot] [kernel?] KASAN: slab-use-after-free Read in irq_migrate_all_off_this_cpu From: syzbot To: linux-kernel@vger.kernel.org, radu@rendec.net, syzkaller-bugs@googlegroups.com, tglx@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 2709dd5ae32f Merge tag 'sched-urgent-2026-08-22' of git://.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=141d2415580000 kernel config: https://syzkaller.appspot.com/x/.config?x=549777c32aabcf9c dashboard link: https://syzkaller.appspot.com/bug?extid=e293654450a72d8e7875 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-2709dd5a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/d2178ccb53ea/vmlinux-2709dd5a.xz kernel image: https://storage.googleapis.com/syzbot-assets/84740cfe4163/bzImage-2709dd5a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e293654450a72d8e7875@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in irq_can_move_pcntxt kernel/irq/internals.h:328 [inline] BUG: KASAN: slab-use-after-free in migrate_one_irq kernel/irq/cpuhotplug.c:57 [inline] BUG: KASAN: slab-use-after-free in irq_migrate_all_off_this_cpu+0xaaf/0xc30 kernel/irq/cpuhotplug.c:181 Read of size 8 at addr ffff88806e9f29a8 by task migration/1/27 CPU: 1 UID: 0 PID: 27 Comm: migration/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Stopper: multi_cpu_stop+0x0/0x4b0 kernel/stop_machine.c:199 <- __stop_cpus.constprop.0+0xb1/0x140 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 irq_can_move_pcntxt kernel/irq/internals.h:328 [inline] migrate_one_irq kernel/irq/cpuhotplug.c:57 [inline] irq_migrate_all_off_this_cpu+0xaaf/0xc30 kernel/irq/cpuhotplug.c:181 fixup_irqs+0x2b/0x280 arch/x86/kernel/irq.c:474 cpu_disable_common arch/x86/kernel/smpboot.c:1371 [inline] native_cpu_disable+0x59/0x80 arch/x86/kernel/smpboot.c:1383 __cpu_disable arch/x86/include/asm/smp.h:73 [inline] take_cpu_down+0xb6/0x190 kernel/cpu.c:1282 multi_cpu_stop+0x16a/0x4b0 kernel/stop_machine.c:239 cpu_stopper_thread+0x21e/0x450 kernel/stop_machine.c:510 smpboot_thread_fn+0x3d3/0xab0 kernel/smpboot.c:160 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8406: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5337 [inline] __kmalloc_noprof+0x324/0x820 mm/slub.c:5362 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] neigh_alloc net/core/neighbour.c:518 [inline] ___neigh_create+0x1532/0x2940 net/core/neighbour.c:652 ip6_finish_output2+0x1052/0x1d50 net/ipv6/ip6_output.c:130 __ip6_finish_output+0x357/0xdf0 net/ipv6/ip6_output.c:210 ip6_finish_output net/ipv6/ip6_output.c:221 [inline] NF_HOOK_COND include/linux/netfilter.h:314 [inline] ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:470 [inline] NF_HOOK include/linux/netfilter.h:325 [inline] ndisc_send_skb+0xa85/0x1bf0 net/ipv6/ndisc.c:513 ndisc_send_rs+0x129/0x680 net/ipv6/ndisc.c:724 addrconf_dad_completed+0x47f/0xff0 net/ipv6/addrconf.c:4396 addrconf_dad_work+0x83c/0x1360 net/ipv6/addrconf.c:4304 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387 process_scheduled_works kernel/workqueue.c:3470 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 55: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2678 [inline] slab_free_freelist_hook mm/slub.c:2707 [inline] slab_free_bulk mm/slub.c:6406 [inline] kmem_cache_free_bulk mm/slub.c:7143 [inline] kmem_cache_free_bulk+0x258/0x730 mm/slub.c:7122 kfree_bulk include/linux/slab.h:910 [inline] kvfree_rcu_bulk+0x176/0x190 mm/slab_common.c:1519 kfree_rcu_work+0x122/0x1a0 mm/slab_common.c:1597 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387 process_scheduled_works kernel/workqueue.c:3470 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 kvfree_call_rcu+0x6a/0x4f0 mm/slab_common.c:1987 neigh_destroy+0x436/0x620 net/core/neighbour.c:943 neigh_release include/net/neighbour.h:459 [inline] neigh_cleanup_and_release+0xfa/0x2d0 net/core/neighbour.c:121 neigh_periodic_work+0x6b6/0xc10 net/core/neighbour.c:1026 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387 process_scheduled_works kernel/workqueue.c:3470 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88806e9f2800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 424 bytes inside of freed 1024-byte region [ffff88806e9f2800, ffff88806e9f2c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88806e9f0000 pfn:0x6e9f0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000240 ffff88801c042dc0 ffffea0001433410 ffffea0001aba210 raw: ffff88806e9f0000 0000000800100008 00000000f5000000 0000000000000000 head: 04fff00000000240 ffff88801c042dc0 ffffea0001433410 ffffea0001aba210 head: ffff88806e9f0000 0000000800100008 00000000f5000000 0000000000000000 head: 04fff00000000003 fffffffffffffe01 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 61, tgid 61 (kworker/3:1), ts 50400280827 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35b0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3267 [inline] allocate_slab mm/slub.c:3382 [inline] new_slab+0xa5/0x640 mm/slub.c:3428 refill_objects+0xe3/0x410 mm/slub.c:7305 refill_sheaf mm/slub.c:2805 [inline] __pcs_replace_empty_main+0x372/0x680 mm/slub.c:4677 alloc_from_pcs mm/slub.c:4775 [inline] slab_alloc_node mm/slub.c:4907 [inline] __do_kmalloc_node mm/slub.c:5336 [inline] __kmalloc_noprof+0x66b/0x820 mm/slub.c:5362 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] ieee802_11_parse_elems_full+0x17c/0x3c90 net/mac80211/parse.c:1071 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2548 [inline] ieee80211_inform_bss+0x159/0x1170 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0x898/0x1dc0 net/wireless/scan.c:2410 cfg80211_inform_bss_data+0x230/0x3c20 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x245/0x7c0 net/wireless/scan.c:3358 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:230 ieee80211_scan_rx+0x4e6/0xb60 net/mac80211/scan.c:364 __ieee80211_rx_handle_packet+0xbab/0xfc0 net/mac80211/rx.c:5427 ieee80211_rx_list+0xf19/0x2160 net/mac80211/rx.c:5720 page last free pid 5140 tgid 5140 ts 50393821474 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4586 [inline] slab_alloc_node mm/slub.c:4919 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4933 alloc_filename fs/namei.c:147 [inline] do_getname+0x35/0x390 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2587 [inline] do_sys_openat2+0xc7/0x1e0 fs/open.c:1416 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88806e9f2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e9f2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806e9f2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806e9f2a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e9f2a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- 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