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 D7E0D3D16E2 for ; Fri, 28 Aug 2026 06:54:18 +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=1787900060; cv=none; b=UVPmzmXCI4rmD4jLTJJfGXyj/ybcuVski4bCJXSBtKwpdm05wr2t42OaPdYRA/tkqiGyFoBwqQIM3ocO9nB2wSiD+kGqjTM2jp4OzweBn+1Aqc/GI5GGL6cBFfnFglAitLczC2a4Xz0ei7Y6fhg47xEu++1bYSv/C/WaN8FcQT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787900060; c=relaxed/simple; bh=dA8xasQmyEHc7JikxyntUJih28ChX8gX0IbxRHC21xo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=fkmCGwrnO9H3K2XtjUUQ9S1MtJuUbF4VdWoHsx+Urb2ViWNDrpIFD4UWkLxxq4exbolneK5mMr/Oo1F4QtLSc5aFNktiMBfNEzg9c+toTjtZWHi8Nf/tbz2OguBAl3BqLEcSJxODyWDYoitI4vcMspcatDi3sYzOYS46sHp5VhI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SvXRwOhq; 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="SvXRwOhq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C8E21F000E9; Fri, 28 Aug 2026 06:54:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787900058; bh=P/T1i/lnHufNVDANJ/6xCKNQiYPnA56P8ZomfV2vzwM=; h=From:To:Cc:Subject:Date:Reply-To; b=SvXRwOhqel7NpBxzO2bQnA2gWLWCOXea1VyUoqiU5iNsBQyE4dyP48vXUVJ/AXbi2 MjpTlOeDkoUUZEHcyabO8v7D9CPKm9gNG2kEh36B772g3vjOpXZoudVsZhAD5ouO3F wdeWUwiUYi+DV8jy0t9yvdm8qHIWjKi1sW/hkPqs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80697: erofs: ensure valid f_path for page cache sharing Date: Fri, 28 Aug 2026 08:53:20 +0200 Message-ID: <2026082805-CVE-2026-80697-4e8a@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=2924; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=kgEAoYBiTnyOYwOjYkd6smyi860Eg1QBLyc3L+dmtgM=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkTDQIjf35hCm1Z/Eta7cGJghDvP5dUdjhcdG9zkssuv yDVfZ+vI5aFQZCJQVZMkeXLNp6j+ysOKXoZ2p6GmcPKBDKEgYtTACbS8IFhwbLf5tstzCxflhy5 uWVLwtrbM7Nt+BjmZ/xJ2nKt4bL6/UtrDm48HMF5j6f8NwA= 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: erofs: ensure valid f_path for page cache sharing Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4): BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ... Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly. The Linux kernel CVE team has assigned CVE-2026-80697 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1.4 with commit 04ba248d02d9eaa3d9077b00a6134caa75fa3e90 and fixed in 7.1.8 with commit 3879657c4ffd81b9a42cf575fc6cb60201032587 Issue introduced in 5.15.217 with commit 7368bec565bac3e536cd43579dbde1e715e6ba61 Issue introduced in 6.1.184 with commit b2f3d94ea310bea9d36d53e9d9b3f45e86c1d893 Issue introduced in 6.6.145 with commit 744b23aa430d52f5c8e4dbff7d71496d6643bed2 Issue introduced in 6.12.96 with commit 8344bdf0629457e532797b42d9d2bbf2a2900bbf Issue introduced in 6.18.39 with commit 5c942ad7df75925ee166e7f0fb36892d8dde376b 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-2026-80697 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/erofs/Kconfig fs/erofs/internal.h fs/erofs/ishare.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/3879657c4ffd81b9a42cf575fc6cb60201032587 https://git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443