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 D3D0440B6E0 for ; Thu, 20 Aug 2026 10:41:34 +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=1787222496; cv=none; b=Y7aTQwnY6q2sygwsLJISgg6XRCEZfYp7+NQ+WsqwyyijDBo7rUd7p6ySJPSgV89tXh2vUUHQAFdsaDDIFSJcIlUh54FeU9I52yTwRoAXusAZJKuhmoA9QuYoJ/o6PNOrF+BNk3fCbv1Se7vIK2ZAhxcbD/GANEws60Lo/RiAiiA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787222496; c=relaxed/simple; bh=n+9HjtOSTMN6lbt1GgLJW9HiKX46GeWNWq3laoPm068=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=XZg74yqqwqBuI7XV8ShaoC00qeY97cOO72VtR0BCvzAvssFgudqAzLkgG4cYOFpw3T5cFmamil8meQjbVdlYKeV1EeczkhGoEJVsXl4SPRCPnFn7qHkfdbBwhCTjhiRzxL9sqiUIzw1dvDoE/SGHELXzU5GtsOVkiPM2AcuAXgA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f3rGP68S; 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="f3rGP68S" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60A4D1F000E9; Thu, 20 Aug 2026 10:41:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787222494; bh=UkZFRKrSTqkqNNrH1KPOwS1G3Fjr0zO7yR5G7hZ7fHg=; h=Subject:To:Cc:From:Date; b=f3rGP68SuMaH1tOXOSZC3zxTDIhFgbYOgQdzi0305h8a8l3NHjGsp8yb1/vIAt3W6 gA/mbjW1AJPzkqLutbC3EFpTMP+xaVSDERu4QAXpD5pLIguN0iw6irQ85eF6g6vbSS z7z5EyCDgpJ13yqPA6S7gFI3h6Ter54uiOv4Ge+g= Subject: FAILED: patch "[PATCH] selinux: require a class's permission values to cover its" failed to apply to 6.18-stable tree To: hexlabsecurity@proton.me,paul@paul-moore.com,stephen.smalley.work@gmail.com Cc: From: Date: Thu, 20 Aug 2026 12:41:20 +0200 Message-ID: <2026082020-deputize-mosaic-579e@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x b98a8ac50775540f3804397ed08f61ef9910bcab # git commit -s git send-email --to '' --in-reply-to '2026082020-deputize-mosaic-579e@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b98a8ac50775540f3804397ed08f61ef9910bcab Mon Sep 17 00:00:00 2001 From: Bryam Vargas Date: Fri, 31 Jul 2026 12:44:10 -0500 Subject: [PATCH] selinux: require a class's permission values to cover its permission count security_get_permissions() sizes an array by the class's permissions.nprim and fills it at value - 1, from the inherited common's permission table and then the class's own. A value no permission defines leaves a NULL that sel_make_perm_files() passes to d_alloc_name(), an oops inside sel_write_load() that strands selinux_state.policy_mutex and leaves every later load in uninterruptible sleep; two permissions sharing a value overwrite the first kstrdup(). Bounding each value by nprim catches neither, and neither would a count: the symbol table is keyed on the permission name, so duplicates pass. Track the values each permission table claims and require them to cover exactly what its count declares, rejecting a count no value can reach. Conforming policies are unaffected. Cc: stable@vger.kernel.org Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy") Signed-off-by: Bryam Vargas Acked-by: Stephen Smalley Signed-off-by: Paul Moore diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 69777e885ae7..d358200817bd 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1154,7 +1154,18 @@ int str_read(char **strp, gfp_t flags, struct policy_file *fp, u32 len) return 0; } -static int perm_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +/* + * Bitmap of the permission values a symtab has claimed. Values are 1-based + * and bounded by SEL_VEC_MAX, the width of an access vector, so the whole set + * fits in a u32 and the callers reject an nprim past that width. + */ +static u32 perm_claimed_mask(u32 nprim) +{ + return nprim ? U32_MAX >> (SEL_VEC_MAX - nprim) : 0; +} + +static int perm_read(struct policydb *p, struct symtab *s, + struct policy_file *fp, u32 *claimed) { char *key = NULL; struct perm_datum *perdatum; @@ -1178,6 +1189,10 @@ static int perm_read(struct policydb *p, struct symtab *s, struct policy_file *f /* indexes an nprim-sized array in security_get_permissions() */ if (perdatum->value > s->nprim) goto bad; + /* two permissions cannot share one slot of that array */ + if (*claimed & (1U << (perdatum->value - 1))) + goto bad; + *claimed |= 1U << (perdatum->value - 1); rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) @@ -1198,7 +1213,7 @@ static int common_read(struct policydb *p, struct symtab *s, struct policy_file char *key = NULL; struct common_datum *comdatum; __le32 buf[4]; - u32 i, len, nel; + u32 i, len, nel, claimed = 0; int rc; comdatum = kzalloc_obj(*comdatum); @@ -1225,17 +1240,28 @@ static int common_read(struct policydb *p, struct symtab *s, struct policy_file if (rc) goto bad; comdatum->permissions.nprim = le32_to_cpu(buf[2]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (comdatum->permissions.nprim > SEL_VEC_MAX) + goto bad; rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; for (i = 0; i < nel; i++) { - rc = perm_read(p, &comdatum->permissions, fp); + rc = perm_read(p, &comdatum->permissions, fp, &claimed); if (rc) goto bad; } + rc = -EINVAL; + if (claimed != perm_claimed_mask(comdatum->permissions.nprim)) { + pr_err("SELinux: common %s does not define every permission it declares\n", + key); + goto bad; + } + hash_eval(&comdatum->permissions.table, "common_permissions", key); rc = symtab_insert(s, key, comdatum); @@ -1369,7 +1395,7 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * char *key = NULL; struct class_datum *cladatum; __le32 buf[6]; - u32 i, len, len2, ncons, nel, val; + u32 i, len, len2, ncons, nel, val, claimed = 0, inherited = 0; int rc; cladatum = kzalloc_obj(*cladatum); @@ -1402,6 +1428,10 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * if (rc) goto bad; cladatum->permissions.nprim = le32_to_cpu(buf[3]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (cladatum->permissions.nprim > SEL_VEC_MAX) + goto bad; ncons = le32_to_cpu(buf[5]); @@ -1436,11 +1466,22 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * } } for (i = 0; i < nel; i++) { - rc = perm_read(p, &cladatum->permissions, fp); + rc = perm_read(p, &cladatum->permissions, fp, &claimed); if (rc) goto bad; } + /* the class's own permissions must claim the slots the common leaves */ + if (cladatum->comdatum) + inherited = cladatum->comdatum->permissions.nprim; + rc = -EINVAL; + if (claimed != (perm_claimed_mask(cladatum->permissions.nprim) & + ~perm_claimed_mask(inherited))) { + pr_err("SELinux: class %s does not define every permission it declares\n", + key); + goto bad; + } + hash_eval(&cladatum->permissions.table, "class_permissions", key); rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp);