From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f71.google.com (mail-oa1-f71.google.com [209.85.160.71]) (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 1CB0E29ACFD for ; Mon, 19 Oct 2026 01:08:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792372114; cv=none; b=bI0OqSzfU4NoA6F2r/wl1GIELtIT9dHmzrnjAbOZ3/MdO2ciTCwgz/TT3q/iiGsa2eRd7pf7sZtL0nNMsjntBu6rO99UcyhcIxPgG5STMVKHIusurp3NYRG+InBbjaWW5OiIqvndL4j/l9xZVl7O1GtZe331NMuXcvqXEYJMjaw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792372114; c=relaxed/simple; bh=p42K430ZcBqHIxS0nWM3yiKs1nh/sx8iWsFs6cJ03aM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=fPD4UjnJ4gStzrWI923rydpy4ioIPYOLo8/OHJhrt+I+BAwLwcjih1ajWRouIfopvPBtmA6gsD9JR9KNzpdmgni0SkEh/5dwmEACTgFGuZ7En2CYP5Rmskm877hlyWsZ3USCBn7xnt9rRPZOz4RKweAvBBk2IQgfU0RNGigGMro= 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=209.85.160.71 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-oa1-f71.google.com with SMTP id 586e51a60fabf-458326d2d9aso2408985fac.2 for ; Sun, 18 Oct 2026 18:08:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792372112; x=1792976912; 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=10eExBUClpAaqEOeBS1LeHVWYKjEkHMLvsM4ks904So=; b=dYfLl43vcASx+TSh/D57hC94vvFEOgdic3xN+MGtqIqdf6VUy3ZkwlEms5fCArsjmP Gf8w0q5MqZl3HD6e8QgKiuprKDqRgN2zkR2aRCZ5d+XSWMWBI9iOjJ5C8HGL5GsVn7gt ZWLWgufv5AruRuXGN4SiWZsTO2o6DC+aR2ZXhVjLopiKCk4qQPQ4gRmoZI4TRVYz92/i Xfu4Tute8EL43p44cRftPjgqYaj0f6m/nw4WuO4C5z+u2Rk+gdFYBVLuR9Gzi9ICffVU A3+5bq1udemFT3uydLe4ZfuUMxyyPJmbm2vm+6gerMO9Y3iheZ3gmf6iKKxtSWJ8+93U qlIg== X-Forwarded-Encrypted: i=1; AKwUvBzF+WHuPgaYgyq10oX0IkC1IBvB5Rfeg1KpKJiG58qOlFaC0lGhVkA0L9LRgkK7Q8TO076o8dJYEvHSC/0=@vger.kernel.org X-Gm-Message-State: AFq9FYLZ6Rzm4YOOAFS2gGn4PkLkdThi1TgQTqUex/jTuA5h1qmxdT/9 AyXaipY+P7wKAXB6cZK9xoriBkwsGKTYoCaS4XvqruSoDbD90WcQAdzH0MWp2hZJmRL1L6JTXap F86eTEEnbfAyGY/ZZKOu12jeTsbLq1Wo+MoFWTrF8JTMuxlhcJ4D7XWZQonI= 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:c40a:b0:4c3:bc6a:a328 with SMTP id 5614622812f47-53ccca4217bmr4634545b6e.31.1792372111987; Sun, 18 Oct 2026 18:08:31 -0700 (PDT) Date: Sun, 18 Oct 2026 18:08:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ad56d8f.6814cce4.34c49f.0143.GAE@google.com> Subject: [syzbot] [dri?] KASAN: slab-use-after-free Read in drm_sysfs_hotplug_event (2) From: syzbot To: airlied@gmail.com, airlied@redhat.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, sean@poorly.run, simona@ffwll.ch, syzkaller-bugs@googlegroups.com, tzimmermann@suse.de Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 0fcb05b72344 Merge tag 'libcrypto-fixes-for-linus' of git:.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=134e7a21580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4118aaa2d227be26 dashboard link: https://syzkaller.appspot.com/bug?extid=f5ecf25277b844fd38f2 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c7b208871bdb/disk-0fcb05b7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/cc9896352195/vmlinux-0fcb05b7.xz kernel image: https://storage.googleapis.com/syzbot-assets/7d6edb0c1319/bzImage-0fcb05b7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f5ecf25277b844fd38f2@syzkaller.appspotmail.com udl 2-1:0.0: [drm] *ERROR* Read EDID byte 0 failed err ffffffb9 ================================================================== BUG: KASAN: slab-use-afte BUG: KASAN: slab-use-after-free in get_kobj_path_length lib/kobject.c:119 [inline] BUG: KASAN: slab-use-after-free in kobject_get_path+0x91/0x2f0 lib/kobject.c:158 Read of size 8 at addr ffff88802a29ee18 by task kworker/1:2/1654 CPU: 1 UID: 0 PID: 1654 Comm: kworker/1:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events output_poll_execute Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 get_kobj_path_length lib/kobject.c:119 [inline] kobject_get_path+0x91/0x2f0 lib/kobject.c:158 kobject_uevent_env+0x29e/0x9e0 lib/kobject_uevent.c:548 drm_sysfs_hotplug_event+0x10e/0x150 drivers/gpu/drm/drm_sysfs.c:451 output_poll_execute+0x846/0xab0 drivers/gpu/drm/drm_probe_helper.c:854 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 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 Allocated by task 5684: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] class_dir_create_and_add drivers/base/core.c:3295 [inline] get_device_parent+0x255/0x3a0 drivers/base/core.c:3355 device_add+0x2d4/0xb80 drivers/base/core.c:3685 drm_minor_register+0x145/0x2e0 drivers/gpu/drm/drm_drv.c:195 drm_dev_register+0x179/0xd80 drivers/gpu/drm/drm_drv.c:1093 udl_usb_probe+0xb7/0x150 drivers/gpu/drm/udl/udl_drv.c:99 usb_probe_interface+0x788/0xe50 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620 device_add+0x7d7/0xb80 drivers/base/core.c:3776 usb_set_configuration+0x1bb5/0x2260 drivers/usb/core/message.c:2274 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620 device_add+0x7d7/0xb80 drivers/base/core.c:3776 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2713 hub_port_connect drivers/usb/core/hub.c:5585 [inline] hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] port_event drivers/usb/core/hub.c:5889 [inline] hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5971 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 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 Freed by task 25: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x1c5/0x650 mm/slub.c:6802 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x222/0x550 lib/kobject.c:737 cleanup_glue_dir+0x1b2/0x220 drivers/base/core.c:3487 device_del+0x77d/0x8f0 drivers/base/core.c:3986 drm_minor_unregister drivers/gpu/drm/drm_drv.c:226 [inline] drm_dev_unregister+0x436/0x700 drivers/gpu/drm/drm_drv.c:1185 drm_dev_unplug+0x4b/0xb0 drivers/gpu/drm/drm_drv.c:507 udl_usb_disconnect+0x3e/0x50 drivers/gpu/drm/udl/udl_drv.c:115 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:618 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372 bus_remove_device+0x444/0x560 drivers/base/bus.c:664 device_del+0x524/0x8f0 drivers/base/core.c:3965 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1484 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2355 hub_port_connect drivers/usb/core/hub.c:5425 [inline] hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] port_event drivers/usb/core/hub.c:5889 [inline] hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5971 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 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 The buggy address belongs to the object at ffff88802a29ee00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 24 bytes inside of freed 96-byte region [ffff88802a29ee00, ffff88802a29ee60) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a29e flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801c041280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000200020 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 50, tgid 50 (kworker/u8:3), ts 7340126275 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] blk_mq_alloc_ctxs block/blk-mq.c:4367 [inline] blk_mq_init_allocated_queue+0xc2/0x13c0 block/blk-mq.c:4644 blk_mq_alloc_queue+0x1ba/0x2e0 block/blk-mq.c:4435 scsi_alloc_sdev+0x79d/0xc60 drivers/scsi/scsi_scan.c:339 scsi_probe_and_add_lun+0x156/0x47b0 drivers/scsi/scsi_scan.c:1228 __scsi_scan_target+0x199/0xd10 drivers/scsi/scsi_scan.c:1805 scsi_scan_channel drivers/scsi/scsi_scan.c:1895 [inline] scsi_scan_host_selected+0x391/0x6c0 drivers/scsi/scsi_scan.c:1924 do_scsi_scan_host drivers/scsi/scsi_scan.c:2057 [inline] do_scan_async+0x10e/0x660 drivers/scsi/scsi_scan.c:2067 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 page_owner free stack trace missing Memory state around the buggy address: ffff88802a29ed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff88802a29ed80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88802a29ee00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88802a29ee80: 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc ffff88802a29ef00: 00 00 00 00 00 00 00 00 00 00 00 00 fc 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