From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) (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 51D272FFFA4 for ; Sat, 10 Jan 2026 10:13:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768039985; cv=none; b=atJU41M8u1RjAC4SvzYRAGinJoa1U7bjB3DCkxYRrBKTHUjuG0fuDvxOhMcPx0pKFRB8s2RujTj+2JNA5Eay0QhdLMyzdnwvXJy6gSET1QtLuloKz9qGF8udtjqneAMmqk0+QMg8wytdT6Wexj+QuBm4EytUbbQ8p6BGk5lp44I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768039985; c=relaxed/simple; bh=eCnGfc6MmVEQTtA/AVF77n7yNhJUjlV7fj43LzdkMaM=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=SqCcJ4z9vJjYzzy0ZhyEE2ED11lxS/WnxIyKOerUmGkmdgPQ9FyOEOR4EIHJqmYJSk2XDE9T4h7LkILxnFoKoI9bDiyE0Ke91tM0Ablancc9BnSAw8XPRpARYjzm8rV4JJ0vMlD0Dh40wEqP9w9Z28TBBLeiXClHpMIj/rjIKqE= 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=209.85.160.69 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-f69.google.com with SMTP id 586e51a60fabf-3fda5f60035so7944294fac.0 for ; Sat, 10 Jan 2026 02:13:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768039982; x=1768644782; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=HV7vGp0xedPgsemg+7/9wSwX79n3yzFSA5rzIhZXQvc=; b=fS/D80j8N+mAlXyWVU2Rx3qGupJ1Fz7DQPNXa3OA7ZRVD2meQ0+YFCjOic57ARTgfi U3vb1DJvYblmpGfMvoBWMv4cjJgvxea/rCBwD1r3GsTn0HqZWfo3nHW/7M1/9eAy2RMl jOoz26ij//mxafNdLKySPFHSR/jLYR0+gnZata3MkbGXn2TsdIMn4PsFFpJ5QLrWQkpg v6/1TjQM0uRnGj9f4NvtjgtEhgoeneCV6WT6gfYoMBFDqYxRRTuQZhDvJn2uUaCb6tOn 8wwdr61ESreJN+SFXZ6GHcV9rDzvh69F+vUg3kBOphRNBRS5LobFHcaUw8G59+HHpRGO E7xw== X-Forwarded-Encrypted: i=1; AJvYcCUwjaUUuZ1o1gBPehyvruHP1y0OQKcdYXVdLzd+xqer1fBq2hoOZia22garprIqrPYuU7sptiX4owtTutI=@vger.kernel.org X-Gm-Message-State: AOJu0Yy5tKy9NUKnzSfm7wT1ArGSxPkNmg094ywRJ5+28r/amulPSUaT rH5WnSmMuri/KPa6UU6r6CM1UeFtIEHiW0IwcPqQSNv1UXmHEq9sUcfaMrO6sP6ellXwwSI8h+4 09nfd5EJDCZasmswEPC6I9Df1mGtm4GAyHHrUFAjHc+Gx6/Rjsy8NILjusnw= X-Google-Smtp-Source: AGHT+IE2RYToHgRH/fYzJwUF9DJSJ33oKnDtiM6JuiVQFrI4G8ifK0oM9cONCa01GLs3W3N4akafG8abFjBmIH7zvTsj75557xWD Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:510d:b0:65d:757:3a02 with SMTP id 006d021491bc7-65f54f75216mr4655875eaf.60.1768039982249; Sat, 10 Jan 2026 02:13:02 -0800 (PST) Date: Sat, 10 Jan 2026 02:13:02 -0800 In-Reply-To: <20260110085030.2131-1-hdanton@sina.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6962262e.050a0220.eaf7.0006.GAE@google.com> Subject: Re: [syzbot] [media?] KASAN: slab-use-after-free Read in em28xx_release_resources From: syzbot To: hdanton@sina.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: slab-use-after-free Read in v4l2_open ================================================================== BUG: KASAN: slab-use-after-free in v4l2_open+0x395/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:444 Read of size 4 at addr ffff88802882c808 by task v4l_id/6679 CPU: 1 UID: 0 PID: 6679 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 v4l2_open+0x395/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:444 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4796 do_filp_open+0x1fa/0x410 fs/namei.c:4823 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f25280a7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd5d4c3160 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f25287b8880 RCX: 00007f25280a7407 RDX: 0000000000000000 RSI: 00007ffd5d4c3f1b RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffd5d4c33b0 R14: 00007f252891f000 R15: 00005609bc9d64d8 Allocated by task 6566: 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:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] em28xx_v4l2_init+0xfe/0x30c0 drivers/media/usb/em28xx/em28xx-video.c:2536 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 6566: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 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+0x1c0/0x660 mm/slub.c:6878 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x181e/0x30c0 drivers/media/usb/em28xx/em28xx-video.c:2906 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 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 ffff88802882c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2056 bytes inside of freed 8192-byte region [ffff88802882c000, ffff88802882e000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28828 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffa7280 ffffea0000bc1600 dead000000000003 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ffa7280 ffffea0000bc1600 dead000000000003 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000a20a01 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5649, tgid 5649 (dhcpcd-run-hook), ts 51915061807, free_ts 51914952418 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xe53/0x1820 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0x111f/0x1f70 security/tomoyo/audit.c:264 tomoyo_supervisor+0x340/0x1480 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x149/0x1e0 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x15ce/0x1aa0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x89/0x270 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve+0x887/0x1400 fs/exec.c:1753 do_execveat_common+0x510/0x6a0 fs/exec.c:1859 page last free pid 5649 tgid 5649 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 __slab_free+0x294/0x320 mm/slub.c:5952 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 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] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x3cf/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_add_entry security/tomoyo/common.c:2132 [inline] tomoyo_supervisor+0xbd5/0x1480 security/tomoyo/common.c:2204 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x149/0x1e0 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x15ce/0x1aa0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x89/0x270 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve+0x887/0x1400 fs/exec.c:1753 do_execveat_common+0x510/0x6a0 fs/exec.c:1859 do_execve fs/exec.c:1933 [inline] __do_sys_execve fs/exec.c:2009 [inline] __se_sys_execve fs/exec.c:2004 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2004 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88802882c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802882c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802882c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802882c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802882c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: b6151c4e Merge tag 'erofs-for-6.19-rc5-fixes' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1213f83a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=323fe5bdde2384a5 dashboard link: https://syzkaller.appspot.com/bug?extid=16062f26c6480975e5ed compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 patch: https://syzkaller.appspot.com/x/patch.diff?x=153d3f92580000