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 36CE5442FCD for ; Tue, 25 Aug 2026 15:09:42 +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=1787670585; cv=none; b=U+s69hNqDOad1m4TxkCNHMwsBVUjhMwj7Zr35WVasQMnuf2GfxH343cn9jumUIyGRzeHcgWuEYan4IvyjoJQspTapWjkZw/BgNqMrJE8oHpJpEYwa25RPUH2BVS5+T5D7/F63jxPH3d2e+QgxzS1LM9Vz3N8N9fr2rBNtsY4txg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787670585; c=relaxed/simple; bh=nJtQ69DlNXkwrwmJusgJMUrenY7JRqJ7UV4OzRw2lCY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VzQ6ZJqyv8mSn3nZr9sI7MWucloF5eHXXldbv2YUmuK+cwtKTIAOt4w1xMSmKK4ivBdkvTbLvGON1u4+o4dCstWT7JPgInOoPZ//rCvmAZASFHRK3sYSQOPOfD/t3n33wLG1botNZs0HsULYc1lJepsCwK5EfFtY8Ug4tpoqcPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TmN21cNf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TmN21cNf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FC161F00A3D; Tue, 25 Aug 2026 15:09:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787670582; bh=XeUWb13Dcn3qlpU7zuqtV14FH8wfu03yZlSFzaWeAWA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TmN21cNfXEJ2DJTr4Tn5YuZ+NSCzfIPdXQvBP7ZbHM7gONgklX17Mpe+8nRPRdT16 V5aE79++lefUH26B1MSf1lFw1+za2/luURXbm3dEzteMqXQUl/0TUlUp9IIbmpvCBw wQ7fb+dOx9QHEcPyLkIeN6UMXY8wuATqWQjkhJTqB4hXibH5zC04kUp4Pr+gYpMrju D1hFp7oUyUdPzrxe1kgO1MsRZT12GzvhhWE1TU4CKQ4XQqqBNj/OOVqeEWthv4e453 KZFkuZXCXtntzrTqiwPtng8nlvTM82dQZSnj2VRuZvhjsJj5GLkw4fJWZVMjtwnnya +IOw7/CfLzEfQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Bryam Vargas , Stephen Smalley , Paul Moore , Sasha Levin Subject: [PATCH 6.1.y 3/3] selinux: require a class's permission values to cover its permission count Date: Tue, 25 Aug 2026 11:09:37 -0400 Message-ID: <20260825150937.4024395-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260825150937.4024395-1-sashal@kernel.org> References: <2026082022-lyrically-condiment-ea5e@gregkh> <20260825150937.4024395-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Bryam Vargas [ Upstream commit b98a8ac50775540f3804397ed08f61ef9910bcab ] 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 [ Kept 6.1's `int i, rc;` declarations and dropped the 3-arg `hash_eval()` context lines absent from this tree. ] Signed-off-by: Sasha Levin --- security/selinux/ss/policydb.c | 51 ++++++++++++++++++++++++++++++---- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 20a9b7a3c204c..e223d78832891 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1108,7 +1108,18 @@ static 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; @@ -1132,6 +1143,10 @@ 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) @@ -1152,7 +1167,7 @@ static int common_read(struct policydb *p, struct symtab *s, struct policy_file char *key = NULL; struct common_datum *comdatum; __le32 buf[4]; - u32 len, nel; + u32 len, nel, claimed = 0; int i, rc; comdatum = kzalloc(sizeof(*comdatum), GFP_KERNEL); @@ -1171,17 +1186,28 @@ 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; + } + rc = symtab_insert(s, key, comdatum); if (rc) goto bad; @@ -1316,7 +1342,7 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * char *key = NULL; struct class_datum *cladatum; __le32 buf[6]; - u32 len, len2, ncons, nel; + u32 len, len2, ncons, nel, claimed = 0, inherited = 0; int i, rc; cladatum = kzalloc(sizeof(*cladatum), GFP_KERNEL); @@ -1336,6 +1362,10 @@ 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]); @@ -1370,11 +1400,22 @@ 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; + } + rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp); if (rc) goto bad; -- 2.53.0