From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 79C0941CB20 for ; Thu, 15 Oct 2026 21:54:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792101241; cv=none; b=kNATdDVuH00Pc2Rt/QS4iFwELyIzTEAihC/wM+Vaw6cc5wK6Qi7cnUzIu/fHPzbcHK7TS4qhoWQWowlTJb5hNYUiflbdsuQMeWFDQ3DgsNMWwKRQuuzm5f24NxKb+oG2RlqFTNVnd45LJFvwunWH0h3QXUirXB7wYQiek95cZpE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792101241; c=relaxed/simple; bh=6uP/8F/UvGjA1xP+F6cvGpDBha1VkeKAjYE4fDfEia8=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=UgP4cXkahJ3f6LaZozvhP/mqa96nDZv3iDiQCBuZqpQ/dip6jVmxnKKzm+QydMOzUDOy65LVrgqMlZnbkUPyg/g3BL3vAxtFLK5kQeqxRi7pTjereFzWwD/bhh+284+1OSri/G2pdUXauoVotXj+6Eivv0UMWBp/1KnKQwNBO1M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GBmWS13k; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GBmWS13k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FAF21F000C5; Thu, 15 Oct 2026 21:53:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792101240; bh=fMfhgzDTfMiI9Mt3cOW7FQTockNxKg+KdRx/YOqcN4s=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=GBmWS13khizDcZyt2NoEHwBE6PXFDYnRrczvsQimstG5WRJRCZSd+tguOwHuHSfwU q8UI95gpwrZxu8+e/BB4BADK5Ll3IvMOtCatdgRnxgTG6YUAOE5RlTg+ir71s+aL2n TpjwYCiHBIM3KhE+ifG4h58FroM5IunI/GV09c6SIIcLqPMBYpLl5/k64RsELK2igI 9vkGsIdR9vNNbvBJ2ABJ0RDKg/TjfEJNf9hfdFpxfkOV9XAA/gRfe7sZN5n8xrjY9e q+fHgBVq408OShmZAbH+330KHNhe9pqnSOV4dunedFJUF5DTdDOokBwFClmccDYYiM FhZ4JWtwgXbjA== From: Thomas Gleixner To: syzbot , linux-kernel@vger.kernel.org, radu@rendec.net, syzkaller-bugs@googlegroups.com Cc: abbotti@mev.co.uk, hsweeten@visionengravers.com Subject: Re: [syzbot] [kernel?] KASAN: slab-use-after-free Read in __setup_irq In-Reply-To: <6ab45d21.80e1c6cc.1e8e5f.0004.GAE@google.com> References: <6ab45d21.80e1c6cc.1e8e5f.0004.GAE@google.com> Date: Thu, 15 Oct 2026 23:53:57 +0200 Message-ID: <87pkxad40a.ffs@fw13> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Wed, Sep 23 2026 at 16:13, syzbot wrote: CC+: Comedy folks > Hello, > > syzbot found the following issue on: > > HEAD commit: fe2ec83746e5 Merge tag 'hid-for-linus-2026092202' of git:/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10e9cd25580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=7d012d9c67977ee4 > dashboard link: https://syzkaller.appspot.com/bug?extid=843bf2f48f4d12e6682e > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/cd25f1c33d2a/disk-fe2ec837.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/2c35e3694ae6/vmlinux-fe2ec837.xz > kernel image: https://storage.googleapis.com/syzbot-assets/1ff8b2a62fde/bzImage-fe2ec837.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+843bf2f48f4d12e6682e@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] > BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:730 > Read of size 1 at addr ffff88802643b8a0 by task syz.0.818/8415 > > CPU: 1 UID: 0 PID: 8415 Comm: syz.0.818 Not tainted syzkaller #0 PREEMPT(full) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026 > 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 > string_nocheck lib/vsprintf.c:648 [inline] > string+0x471/0x4d0 lib/vsprintf.c:730 > vsnprintf+0x422/0x1300 lib/vsprintf.c:2949 > vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307 > vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455 > _printk+0xcf/0x110 kernel/printk/printk.c:2504 > __setup_irq.cold+0x3be/0x3f1 kernel/irq/manage.c:1821 > request_threaded_irq+0x261/0x3e0 kernel/irq/manage.c:2184 > request_irq include/linux/interrupt.h:176 [inline] > pcl812_attach+0x1b62/0x2300 drivers/comedi/drivers/pcl812.c:1174 > comedi_device_attach+0x40e/0x6b0 drivers/comedi/drivers.c:1101 > do_devconfig_ioctl+0x1b3/0x6d0 drivers/comedi/comedi_fops.c:930 > comedi_unlocked_ioctl+0x860/0x3310 drivers/comedi/comedi_fops.c:2302 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:597 [inline] > __se_sys_ioctl fs/ioctl.c:583 [inline] > __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 > do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] > do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7fcaa579e159 > 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:00007fcaa6663028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007fcaa5a25fa0 RCX: 00007fcaa579e159 > RDX: 0000200000000240 RSI: 0000000040946400 RDI: 0000000000000006 > RBP: 00007fcaa583506b R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007fcaa5a26038 R14: 00007fcaa5a25fa0 R15: 00007fffa588bd58 > > > Allocated by task 1: > 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:5414 [inline] > __kmalloc_node_track_caller_noprof+0x33d/0x870 mm/slub.c:5545 > kvasprintf+0xbc/0x150 lib/kasprintf.c:25 > kasprintf+0xc7/0x100 lib/kasprintf.c:59 > serial_core_add_one_port drivers/tty/serial/serial_core.c:3106 [inline] > serial_core_register_port+0x46b/0x1660 drivers/tty/serial/serial_core.c:3353 > serial8250_register_8250_port+0x16c7/0x2440 drivers/tty/serial/8250/8250_core.c:877 > serial_pnp_probe+0x443/0x950 drivers/tty/serial/8250/8250_pnp.c:480 > pnp_device_probe+0x2b3/0x4a0 drivers/pnp/driver.c:111 > call_driver_probe drivers/base/dd.c:628 [inline] > really_probe+0x241/0xa60 drivers/base/dd.c:706 > __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 > driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 > __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292 > bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383 > bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763 > driver_register+0x1e2/0x360 drivers/base/driver.c:174 > serial8250_init+0xcc/0x1c0 drivers/tty/serial/8250/8250_platform.c:318 > do_one_initcall+0x11c/0x6f0 init/main.c:1362 > do_initcall_level init/main.c:1424 [inline] > do_initcalls init/main.c:1440 [inline] > do_basic_setup init/main.c:1460 [inline] > kernel_init_freeable+0x6ea/0x7b0 init/main.c:1675 > kernel_init+0x21/0x1e0 init/main.c:1565 > 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 8240: > 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:2748 [inline] > slab_free mm/slub.c:6508 [inline] > kfree+0x22b/0x6d0 mm/slub.c:6801 > serial_core_remove_one_port drivers/tty/serial/serial_core.c:3222 [inline] > serial_core_unregister_port+0x4b9/0x960 drivers/tty/serial/serial_core.c:3383 > serial8250_unregister_port+0x1db/0x890 drivers/tty/serial/8250/8250_core.c:932 > pnp_device_remove+0x7f/0x250 drivers/pnp/driver.c:133 > device_remove+0xcb/0x180 drivers/base/dd.c:616 > __device_release_driver drivers/base/dd.c:1349 [inline] > device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372 > unbind_store+0xf8/0x110 drivers/base/bus.c:244 > drv_attr_store+0x74/0xb0 drivers/base/bus.c:125 > sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 > kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 > new_sync_write fs/read_write.c:595 [inline] > vfs_write+0x6af/0x1050 fs/read_write.c:687 > ksys_write+0x12a/0x250 fs/read_write.c:739 > do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] > do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > The buggy address belongs to the object at ffff88802643b8a0 > which belongs to the cache kmalloc-8 of size 8 > The buggy address is located 0 bytes inside of > freed 8-byte region [ffff88802643b8a0, ffff88802643b8a8) > > The buggy address belongs to the physical page: > page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2643b > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 00fff00000000000 ffff88801c034500 dead000000000100 dead000000000122 > raw: 0000000000000000 0000000000800080 00000000f5000000 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 4167969447 > 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/0x35d0 mm/page_alloc.c:3943 > __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 > alloc_slab_page mm/slub.c:3347 [inline] > allocate_slab mm/slub.c:3462 [inline] > new_slab+0xa9/0x6e0 mm/slub.c:3513 > refill_objects+0xe3/0x410 mm/slub.c:7417 > refill_sheaf mm/slub.c:2885 [inline] > __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 > alloc_from_pcs mm/slub.c:4850 [inline] > slab_alloc_node mm/slub.c:4984 [inline] > __do_kmalloc_node mm/slub.c:5413 [inline] > __kmalloc_node_track_caller_noprof+0x6a8/0x870 mm/slub.c:5545 > __kmemdup_nul mm/util.c:64 [inline] > kstrdup+0x51/0xe0 mm/util.c:84 > kstrdup_const+0x63/0x80 mm/util.c:104 > kvasprintf_const+0x10f/0x1a0 lib/kasprintf.c:48 > kobject_set_name_vargs+0x5a/0x140 lib/kobject.c:274 > dev_set_name+0xc7/0x100 drivers/base/core.c:3564 > tty_register_device_attr+0x2fb/0x7f0 drivers/tty/tty_io.c:3230 > tty_register_device drivers/tty/tty_io.c:3171 [inline] > tty_register_driver+0x769/0xb50 drivers/tty/tty_io.c:3449 > legacy_pty_init drivers/tty/pty.c:579 [inline] > pty_init+0x65d/0xdc0 drivers/tty/pty.c:919 > do_one_initcall+0x11c/0x6f0 init/main.c:1362 > page_owner free stack trace missing > > Memory state around the buggy address: > ffff88802643b780: 05 fc fc fc 05 fc fc fc 05 fc fc fc 05 fc fc fc > ffff88802643b800: 05 fc fc fc 05 fc fc fc 05 fc fc fc 05 fc fc fc >>ffff88802643b880: 05 fc fc fc fa fc fc fc 05 fc fc fc fa fc fc fc > ^ > ffff88802643b900: fa fc fc fc 05 fc fc fc fa fc fc fc fa fc fc fc > ffff88802643b980: fa fc fc fc 04 fc fc fc 00 fc fc fc 00 fc fc fc > ================================================================== > > > --- > 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