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 CCAC438D6A8 for ; Sun, 18 Oct 2026 15:36:13 +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=1792337775; cv=none; b=JupLJ4ALhGJxgjkDz/F3TDdydz/EXyFsBEWhAYVZAt1lj4OsSfvPfe6b1VJGtr/grSJkt4ZBh3fG15g4Rl0rf9E89bDTHi4sJNGN5t9reyicUursxBWiM95KS0e5Ln08BfMP68H1BcUkYgavOcVj7Alc97MNG6w0B/32PVx/p84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792337775; c=relaxed/simple; bh=gOzb4gUxBbT2hc5EEC+IQP1tTr6rbWKCD2UhnOC7srs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HSZ5yNITbS0lJbsM0t96biKj5YD2RAQuvwk4sYd9unaik1oqEYLue6vuoNPpJ1XEGZJPOImzmbmTFeJ4fLQh2F+CmGdZ+KR47EK/5O8HEsoZnWtWGVNopT6naLvuHJ0SzDU9e4xoEDcDMEBWw8M97vQgRGjE5r7CDxs6KPjzBYU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tP5lhW7c; 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="tP5lhW7c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22B651F000C4; Sun, 18 Oct 2026 15:36:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792337773; bh=gNUB9BVjzc6JZhSG+aQDFXcDp9zzc7E1SF99hvPanI0=; h=From:To:Cc:Subject:Date:Reply-To; b=tP5lhW7cPAPG8FiQTT6GXm29A/tzJr8LDm2LfDfO996qj1zKOMLZ+8INIBppKE+oh b/uX9qIRi7irp5lopOZ159oKIMx11GkYoeMwXsirF0KSYrgaERIkjwSZ/DQazUZIPC /v/EiBXDSeMeA/3EyDr0xwTRuYLNvGXMsMbKkp3c= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-98636: squashfs: Add dictionary size range check to prevent shift-out-of-bounds Date: Sun, 18 Oct 2026 17:18:20 +0200 Message-ID: <2026101845-CVE-2026-98636-46cb@gregkh> X-Mailer: git-send-email 2.56.0 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=3747; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=OIqX317HwTOlihscC72xjbTyVwbs492zrY3WcXlRSig=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlXHi3smCkyzy5ujvzCaQdan8TuuztdOrw8uKV4zYlS4 9RVbvs5O2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAiTNsZFlyNOmem9aj4pLtC kafShcOfUztc7jLMjxWOXldYub0yesKL52GVSXxe2Y7pAA== 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: squashfs: Add dictionary size range check to prevent shift-out-of-bounds When an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size is 0) is mounted, and performs shift operations using dictionarysize, the shift exponent is -1, causing a shift-out-of-bounds. Detail as below: squashfs_comp_opts(msblk, buffer, length) squashfs_xz_comp_opts() if (comp_opts) n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + (1 << (n + 1))) <----shift-out-of-bounds Fix it by adding a dictionary size range check before the shift operation. The Linux kernel CVE team has assigned CVE-2026-98636 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 5.10.271 with commit b02948a23455f8190a53887b2d2c13ae1d360cea Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 5.15.222 with commit 9d9c5c218ea356a1d88765214ad2919605280ab1 Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 6.1.189 with commit 7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1 Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 6.6.158 with commit c68e0068a236f9a7dfc19720bdf11e5d80a85089 Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 6.12.112 with commit 88c673a0bd233df44ca0020da82f4fd3876de27a Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 6.18.55 with commit 0cb85377daaefb4ce5ce72975f2deb27ee0e0cad Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 7.2.9 with commit e1ca4e3a380ef3e8f46ce006f1146392e3f32c98 Issue introduced in 2.6.39 with commit ff750311d30acc9564ef577050794953eee59f01 and fixed in 7.3-rc5 with commit 1f7745fb3580152ca902ef181b605f33cabfb1d0 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-2026-98636 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/squashfs/xz_wrapper.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/b02948a23455f8190a53887b2d2c13ae1d360cea https://git.kernel.org/stable/c/9d9c5c218ea356a1d88765214ad2919605280ab1 https://git.kernel.org/stable/c/7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1 https://git.kernel.org/stable/c/c68e0068a236f9a7dfc19720bdf11e5d80a85089 https://git.kernel.org/stable/c/88c673a0bd233df44ca0020da82f4fd3876de27a https://git.kernel.org/stable/c/0cb85377daaefb4ce5ce72975f2deb27ee0e0cad https://git.kernel.org/stable/c/e1ca4e3a380ef3e8f46ce006f1146392e3f32c98 https://git.kernel.org/stable/c/1f7745fb3580152ca902ef181b605f33cabfb1d0