From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f80.google.com (mail-oo1-f80.google.com [209.85.161.80]) (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 5602A3EFD0F for ; Thu, 22 Jan 2026 08:53:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769072014; cv=none; b=So5ZccVgUDtonvJfiq60DSQFekVu3E7/vG0dNnTdy1fq7l+F6UFiGBG/8jJWaUa9e/OTTy0Y7j3aDZvOK0QUmSBMrMHBVK1Ry4GXxE3reYM7meZrx5ZwPZWhLlTKUvC5lV82IeRuDBu3jR9SgZOY90n4PEj4plt/oXYfgzwt0Ws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769072014; c=relaxed/simple; bh=UTDZk7ZvLY5cFz80JynOFk++a558mvAGF+m1Y0bIDpw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=ZSJh/gcFAqF0p5VTs4RWTxGiDSsa3Z0AQU4CxQ8lv5x49KRIw7JSrCmY6q+xlQ2o7zPVm0Z1E+bKtwyUcTCElefSjMah8AL7BfZo6HRwXWTJooP7DSC/YL+KujTaMYbyKCSgtdKIUpjs477U73RTWUZso+Fhs/GWzGvkSNUJ+aA= 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=209.85.161.80 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-oo1-f80.google.com with SMTP id 006d021491bc7-662c78da1c4so116562eaf.1 for ; Thu, 22 Jan 2026 00:53:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769072011; x=1769676811; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=PCEPG624hjG44ajr4KRdg/TDTcq4sVGy6ScMHuZ3R+4=; b=QZHvZx+7rViU8oewP5D/kqVMJGzL5Gt9FkdjHwzni8yFrkwJFad2pERAouRT62DVHL wUROfKm6sfZIaXebLWb6VA67rL/xnv23mcTrsrOyiltdacxgZXkmLRTZjqXJSCRJUST7 b75qDJ6GiQUe1C3qVGnbgLgP1Dj6eidY3a5CD1p4JWa3oV9pE3O4bz5ETFa/l7ZEce9N UU9h2w/4VQfqScn3R8mmPaaNuGe2bf+mM5HEvrtzxG/1SFOVSyQj5pc/Ih9ciWixIJq9 psJKAnShyaoTYx7blWvHAP+1glXX+GE66RJdWcSlWt9cxIV0iaNW4yK6gAr4h+TYFMqA WmWA== X-Forwarded-Encrypted: i=1; AJvYcCWmvAN69rXNivRvuzGhZ2E72zgyFpPcu++SPXSxwhe9l6bmpJ+jhcquM8uyA8z13EOtK0aJpnHKYKm2aw==@vger.kernel.org X-Gm-Message-State: AOJu0YwiWMaUjxcCT+AlzXqn89rVV1Mjsa3N1IUbzWmay7lFWzDubTyG 7CITHR2TqkRq+F0idrmQcDQtdSivtjhkKXAmRD7XJhQhozOFIhM7TAgnM+ASB5RwMm6ZemNaQaQ QB7FDfhYoUYNVvHEcY/+qEMKzv2X7/+81Xz17EwF/faW7ZZqsCDvaGoZNJKg= Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1629:b0:662:c7bf:e0e0 with SMTP id 006d021491bc7-662c7bfe2eemr176762eaf.2.1769072011288; Thu, 22 Jan 2026 00:53:31 -0800 (PST) Date: Thu, 22 Jan 2026 00:53:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6971e58b.a00a0220.3ad28e.9c56.GAE@google.com> Subject: [syzbot] [media?] KASAN: slab-use-after-free Read in em28xx_unregister_media_device From: syzbot To: laurent.pinchart@ideasonboard.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-usb@vger.kernel.org, mchehab@kernel.org, sakari.ailus@linux.intel.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 5ac87cd859ec Merge 6.19-rc6 usb-next git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing console output: https://syzkaller.appspot.com/x/log.txt?x=140e73fa580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a04e768f944f1aa0 dashboard link: https://syzkaller.appspot.com/bug?extid=07b93bb3189febcab189 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/b927a84e0088/disk-5ac87cd8.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b8131bd9dbee/vmlinux-5ac87cd8.xz kernel image: https://storage.googleapis.com/syzbot-assets/24fc40a81925/bzImage-5ac87cd8.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+07b93bb3189febcab189@syzkaller.appspotmail.com em28xx 8-1:0.132: Closing input extension ================================================================== BUG: KASAN: slab-use-after-free in media_device_unregister drivers/media/mc/mc-device.c:804 [inline] BUG: KASAN: slab-use-after-free in media_device_unregister+0x565/0x5e0 drivers/media/mc/mc-device.c:782 Read of size 8 at addr ffff88813572c210 by task kworker/1:6/5730 CPU: 1 UID: 0 PID: 5730 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: usb_hub_wq hub_event 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+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 media_device_unregister drivers/media/mc/mc-device.c:804 [inline] media_device_unregister+0x565/0x5e0 drivers/media/mc/mc-device.c:782 em28xx_unregister_media_device+0x4e/0xe0 drivers/media/usb/em28xx/em28xx-cards.c:3511 em28xx_release_resources+0x79/0x1b0 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect.cold+0x17d/0x253 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:563 __device_release_driver drivers/base/dd.c:1282 [inline] device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1305 bus_remove_device+0x22f/0x440 drivers/base/bus.c:616 device_del+0x376/0x9b0 drivers/base/core.c:3878 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1418 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 11958: 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+0x8f/0xa0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] em28xx_v4l2_init.cold+0x94/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 11958: 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+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1ad/0x630 mm/slub.c:6878 kref_put.isra.0+0x56/0x90 include/linux/kref.h:65 em28xx_v4l2_init.cold+0x280/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88813572c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 528 bytes inside of freed 8192-byte region [ffff88813572c000, ffff88813572e000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x135728 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042280 ffffea00046dc600 dead000000000002 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042280 ffffea00046dc600 dead000000000002 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 0200000000000003 ffffea0004d5ca01 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1122, tgid 1122 (kworker/1:2), ts 1154723928347, free_ts 1154474178179 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xd57/0x3b20 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x269/0x2230 mm/page_alloc.c:5240 alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x5c3/0x990 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] hcd_buffer_alloc+0x1f5/0x290 drivers/usb/core/buffer.c:134 usb_alloc_coherent+0x5f/0xa0 drivers/usb/core/usb.c:1010 hdpvr_alloc_buffers+0x12e/0x650 drivers/media/usb/hdpvr/hdpvr-video.c:162 hdpvr_probe.cold+0x929/0x12fe drivers/media/usb/hdpvr/hdpvr-core.c:350 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 page last free pid 2860 tgid 2860 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7d1/0x1010 mm/page_alloc.c:2973 discard_slab mm/slub.c:3346 [inline] __put_partials+0x127/0x160 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x292/0x7d0 mm/slub.c:5315 __alloc_skb+0x156/0x410 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] netlink_alloc_large_skb+0x69/0x150 net/netlink/af_netlink.c:1184 netlink_sendmsg+0x680/0xda0 net/netlink/af_netlink.c:1869 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88813572c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813572c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88813572c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813572c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813572c300: 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