From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f46.google.com (mail-qv1-f46.google.com [209.85.219.46]) (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 B94991FC7C5 for ; Mon, 15 Jun 2026 02:15:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781489716; cv=none; b=RN/vCnNdVCWrRQBUtE/EUeYzXC/b7BHM1ygvtkEhTjw+gmzlteBnCvrJZUXNgr+stgwemiEYpb/OSm5uw2J891LRxHP5oRvgi3OS3MBrNtHMnM7s6Fpo/LN7APDzoIL43J5AoNWoRYEGHHMExSVZwN5PLEAbJ48egzj9DBAhbuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781489716; c=relaxed/simple; bh=gyjz/USqjUUtM62ty/LRr7o6O6v2mzhDa0axURjvys0=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; b=KIzIjJG8P3NgzvdVjDTwcAXdVbPG3EL7ZHcBoVmQCMVMPb0+daUXPTRZGkKb+PSjPnNY9wMaZXztgUE825VeB9UYWEMu4D9b271KMM6+sVeYe6JDklnOJ7SK+KxSVFfGUVRv2Y9NRC0N9yCXkeKVNDVMpIcleu5xEN5MzzFz8Gs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=oKH6HG9J; arc=none smtp.client-ip=209.85.219.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oKH6HG9J" Received: by mail-qv1-f46.google.com with SMTP id 6a1803df08f44-8ccef9eabccso40282966d6.1 for ; Sun, 14 Jun 2026 19:15:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781489711; x=1782094511; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:from:to:cc:subject:date:message-id:reply-to; bh=Dgs8zi4UB7t/plEWUkJHCQvofyIKmiToTSGYIIN2vkI=; b=oKH6HG9J7mdqg1cvcFmByA+uLIzS8ZX6O2HF2P84ewmRZF/aO8R+Qg/dlFSSN/09XV aOURHT6qcKBOUuIw4jj78edELRrFNyuIw4kerq7etpHRpwYg0+gJrTN4loVU6FeGGT+W 0Ixzyz430IXXFg8hIFsVUn+EY6b5nSFELU9heDKR9RVGhEmewJHVVGHMKoyMf+4HiMD/ 2hOaXI0AGY+czjXkwbR+a7rVBvMOlmrfibf4QoICUmgx3/DNgV01VzIhcEhNB8n9Q9xi xIA8R+5D/pULPHZCUywYC4Z9LBnbc6xm97xB64573ezt+Ba7yK5gLykSHAtZvCG9+y/0 vvSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781489711; x=1782094511; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Dgs8zi4UB7t/plEWUkJHCQvofyIKmiToTSGYIIN2vkI=; b=Md1ZW1vaWgYWN6C4+0BxkIFt31pQWB1qUy6PPZvu8h4ycDqWmPAIbhVBGZqEbjymJk C3hdw1VCSWX6H9jslHW9LXNwKIcA3rIVj/q6z+yHHz8zUfaZtpUQ5ufItfXInXErac3Y YU+r8sUaxz4q/3cXOSNNNj7Hht2/+/etw7FheFM6JiPpUtey7clc8jo/Q49ZEADPQQo+ n9kgjKyspdY0YMfJ/B1Iiiq8q64roixK7/eLBtrOVjO4kXirt7BN65aHDA0+zLJ+I3Dz ortmjdzmRa9MBJ+2j0MsG/DU7qVOW2nIliUKhNv+vpPwdybwfQ9e7XS06f82zogbejf1 En8Q== X-Forwarded-Encrypted: i=1; AFNElJ+PGZ0NtE4s7R7+tStNMHGOBG/4xP2BU7q1DCKaaHWeAoVMiIyHeTUsitSfP7GhdCFhtU/4Kf123IDc7xk=@vger.kernel.org X-Gm-Message-State: AOJu0Yz37rmXJozol3e3Z71rTVl0aXMiI4uDxd2bk8F2WYX7qJ48fvhi Ezt2vyZXvle+h5Irl7cJAF4S+VLCxV9fAZBhe5ztZDdEwl02lFmq69KR X-Gm-Gg: Acq92OGTVGirgdzTMdHs7DgRQ4Dz2yHhyLSMNzVxKv+J9LxaZ9eXJoGgJAA0lidb1Vi cZ4YG7FxY4PellNuei1C7Cogotwdx3kcieHwo4GS/P4wfMyoBvUjtYSOc27ECS9riGToMp71doz 3sEYaZvzk/+a7zFehRm1nTUzjAOoYMP0ao7jHLxaDXtch9Jpz0u4aROjOaxRSC1NREdhLqEkWVE SERh+tkPFRUOGyNBWBP/U/iJJMeoWcnHrG+0nqkUwhHhgHWF6RQrgAdzcNOt0FDWs53YnXN7n0R zEt10mlxz3NGjae2sSJiBFuwzEYURsLQ9xm4H68CTcTKAIWy0dVEtlIyQRkcAEw5synxOelZssG Du6FgghVtD1/r3k/W7hFC/BA7N4j9YM81AoVp7NipKtrL/NebjqAO8/SfPutovJ0i4RyCDLZYTM au8BkXBMmklM7xhykV7RL9ktsnd785Vx9MICNYBhvAPY5VY6awKNPFEI9gqH//KNfcNzO5Mg== X-Received: by 2002:a05:622a:1819:b0:517:5bc6:b575 with SMTP id d75a77b69052e-517fbc898cfmr172653761cf.4.1781489710652; Sun, 14 Jun 2026 19:15:10 -0700 (PDT) Received: from localhost.localdomain ([2601:985:4601:5df0:2106:6ce9:6b1:8f70]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8d305134b20sm96793466d6.43.2026.06.14.19.15.10 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sun, 14 Jun 2026 19:15:10 -0700 (PDT) From: Shuangpeng Bai To: dwmw2@infradead.org, richardcochran@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [BUG] ptp: vmclock: KASAN slab-use-after-free in vmclock_miscdev_read Date: Sun, 14 Jun 2026 22:15:08 -0400 Message-ID: <178144969601.60470.14493569608271069160@gmail.com> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, I hit the following KASAN report while testing current upstream kernel. The issue was reproduced by opening /dev/vmclock0, unbinding the vmclock platform device, and then reading from the old fd. KASAN: slab-use-after-free in vmclock_miscdev_read I reproduced this on commit: e8c2f9fdadee7cbc75134dc463c1e0d856d6e5c7 (May 25 2026) The reproducer and .config files are here. https://gist.github.com/shuangpengbai/7c2d117852611448a80026f8aa4d4bc4 I'm happy to test debug patches or provide additional information. Reported-by: Shuangpeng Bai [ 148.011605][ T8390] BUG: KASAN: slab-use-after-free in vmclock_miscdev_read (drivers/ptp/ptp_vmclock.c:409) [ 148.015241][ T8390] Read of size 8 at addr ffff88811fdc7478 by task repro_vmclock_o/8390 [ 148.018209][ T8390] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 148.018216][ T8390] Call Trace: [ 148.018226][ T8390] [ 148.018232][ T8390] dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) [ 148.018248][ T8390] print_report (mm/kasan/report.c:378 mm/kasan/report.c:482) [ 148.018314][ T8390] kasan_report (mm/kasan/report.c:595) [ 148.018335][ T8390] vmclock_miscdev_read (drivers/ptp/ptp_vmclock.c:409) [ 148.018384][ T8390] vfs_read (fs/read_write.c:572) [ 148.018453][ T8390] __x64_sys_pread64 (fs/read_write.c:765 fs/read_write.c:773 fs/read_write.c:770 fs/read_write.c:770) [ 148.018483][ T8390] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) [ 148.018498][ T8390] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) [ 148.018604][ T8390] [ 148.042173][ T8390] Freed by task 8390 on cpu 1 at 147.908511s: [ 148.042791][ T8390] kasan_save_track (mm/kasan/common.c:57 mm/kasan/common.c:78) [ 148.043265][ T8390] kasan_save_free_info (mm/kasan/generic.c:584) [ 148.043775][ T8390] __kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285) [ 148.044256][ T8390] kfree (include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566) [ 148.044668][ T8390] devres_release_all (drivers/base/devres.c:50 drivers/base/devres.c:547 drivers/base/devres.c:576) [ 148.045171][ T8390] device_release_driver_internal (drivers/base/dd.c:598 drivers/base/dd.c:1357 drivers/base/dd.c:1375) [ 148.045791][ T8390] unbind_store (drivers/base/bus.c:244) [ 148.046252][ T8390] kernfs_fop_write_iter (fs/kernfs/file.c:352) [ 148.046798][ T8390] vfs_write (fs/read_write.c:595 fs/read_write.c:688) [ 148.047229][ T8390] ksys_write (fs/read_write.c:740) [ 148.047678][ T8390] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) [ 148.048144][ T8390] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) [ 148.048996][ T8390] The buggy address belongs to the object at ffff88811fdc7400 [ 148.048996][ T8390] which belongs to the cache kmalloc-512 of size 512 [ 148.050394][ T8390] The buggy address is located 120 bytes inside of [ 148.050394][ T8390] freed 512-byte region [ffff88811fdc7400, ffff88811fdc7600) Best, Shuangpeng