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 CBF6D3EC2F8 for ; Sat, 15 Aug 2026 12:29:36 +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=1786796977; cv=none; b=Yivb/A8ZyNud9r/qQmUaV2SLQfV1WFUiDUvcJErw0m+S9mEtwyBUaUVjfb0ym0FqpYaHPYOm5AFshb5R8yNx0LUWYWOP76jphKeFRukmDVuVD7gw7wKU8jfOwfwh3v5vLRvcSAF7zmv/GQSek12gkqpcF4uuORv+GZBksifYT3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786796977; c=relaxed/simple; bh=+96EaQt+gDRhD9lpzrNdUJj93ihnwLn3ShoCjnebbY4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Cr1DdsEk9Sfph/u/6BTJRVhXg3Ei6yJMp8ZLlguyQalaoYgo7/OdLDPFj+LKheRvzGRbmD4f/Oo4JKF05o6mO6Yz+A7uRMFlIm4HqV5TzKM/OLEJfMWIrpW8ycWX3t9dhheW2b9i+M2jAIj7KNXdRnpQHkyCZ5CCYNVGNxWsy0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mHbizm79; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mHbizm79" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F9CB1F000E9; Sat, 15 Aug 2026 12:29:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786796976; bh=VPHFL2IqmpjYvd2/5nW1iPD/2BB7GEZbf5s3jYpv1XM=; h=From:To:Cc:Subject:Date:Reply-To; b=mHbizm79e37pxJjbjUum/aVMqHDuQgrhLBtROSYSczT16oAnzaA4UBPoeeXfpRLx3 AnXoCr4w2SmWN9yj6GsxPGJ1TB8oryJhl8kNLZcKhM1aMrX2l9KNz5NNktYzNczoPr YzdQXTCT3VEN/W4vu8Shb8T9Y3Qtb5VS//iGXcrk= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-74487: binfmt_misc: restore write access when removing an entry Date: Sat, 15 Aug 2026 21:26:08 +0900 Message-ID: <2026081538-CVE-2026-74487-5fbf@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2796; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=U4hNWWfa1MIewdZKhFea85GjO+w9DNd1d1/yry0/VB0=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNUYf4ysw+7HnYKa2rnRC0Ku6y/ua3z32Kme+saTm/s TexVetVRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzk9EmG+d7cyy5ncUiHlgS9 y+0tXHWR9aKuCsMspkeF/2Rjpkzx+vKy90dA29ZJ5UtFAQ== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: restore write access when removing an entry Registering an entry with the MISC_FMT_OPEN_FILE flag opens the interpreter via open_exec() which denies write access to it for as long as the entry exists. Removing the entry closes the interpreter file via filp_close() but never restores write access, leaving the inode's i_writecount permanently negative. Opening the interpreter for writing keeps failing with ETXTBSY long after the entry is gone until the inode is evicted from the inode cache. Commit 90f601b497d7 ("binfmt_misc: restore write access before closing files opened by open_exec()") fixed the same imbalance in the error path of bm_register_write() but the actual removal path has been leaking the write denial since the introduction of the flag. Restore write access in put_binfmt_handler() before closing the interpreter file. The Linux kernel CVE team has assigned CVE-2026-74487 to this issue. Affected and fixed versions =========================== Issue introduced in 4.8 with commit 948b701a607f123df92ed29084413e5dd8cda2ed and fixed in 6.18.44 with commit fdc1d702bf3001586221fa07e598e876a0a854c5 Issue introduced in 4.8 with commit 948b701a607f123df92ed29084413e5dd8cda2ed and fixed in 7.1.8 with commit 3b522487a3a9162b1b519eefde7998d103e3e07b Issue introduced in 4.8 with commit 948b701a607f123df92ed29084413e5dd8cda2ed and fixed in 7.2-rc6 with commit db1856ea9196cf6e015d12199a34c0b9313c7bfa Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-74487 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: fs/binfmt_misc.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/fdc1d702bf3001586221fa07e598e876a0a854c5 https://git.kernel.org/stable/c/3b522487a3a9162b1b519eefde7998d103e3e07b https://git.kernel.org/stable/c/db1856ea9196cf6e015d12199a34c0b9313c7bfa