[RFC,v2,10/22] selinux: use u16 for security classes

Message ID	20241216164055.96267-10-cgoettsche@seltendoof.de (mailing list archive)
State	New
Headers	show Received: from server02.seltendoof.de (server02.seltendoof.de [168.119.48.163]) (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 2D340207E00; Mon, 16 Dec 2024 16:41:44 +0000 (UTC) From: =?utf-8?q?Christian_G=C3=B6ttsche?= <cgoettsche@seltendoof.de> To: selinux@vger.kernel.org Cc: =?utf-8?q?Christian_G=C3=B6ttsche?= <cgzones@googlemail.com>, Paul Moore <paul@paul-moore.com>, Stephen Smalley <stephen.smalley.work@gmail.com>, Ondrej Mosnacek <omosnace@redhat.com>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, Bill Wendling <morbo@google.com>, Justin Stitt <justinstitt@google.com>, =?utf-8?q?Thi=C3=A9baud_Weksteen?= <tweek@google.com>, =?utf-8?q?Bram_Bonn?= =?utf-8?q?=C3=A9?= <brambonne@google.com>, Masahiro Yamada <masahiroy@kernel.org>, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Casey Schaufler <casey@schaufler-ca.com>, John Johansen <john.johansen@canonical.com>, GUO Zihua <guozihua@huawei.com>, Canfeng Guo <guocanfeng@uniontech.com> Subject: [RFC PATCH v2 10/22] selinux: use u16 for security classes Date: Mon, 16 Dec 2024 17:40:08 +0100 Message-ID: <20241216164055.96267-10-cgoettsche@seltendoof.de> In-Reply-To: <20241216164055.96267-1-cgoettsche@seltendoof.de> References: <20241216164055.96267-1-cgoettsche@seltendoof.de> Reply-To: cgzones@googlemail.com Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Series	[RFC,v2,01/22] selinux: supply missing field initializers \| expand [RFC,v2,01/22] selinux: supply missing field initializers [RFC,v2,02/22] selinux: avoid using types indicating user space interaction [RFC,v2,03/22] selinux: align and constify functions [RFC,v2,04/22] selinux: rework match_ipv6_addrmask() [RFC,v2,05/22] selinux: avoid nontransitive comparison [RFC,v2,06/22] selinux: rename comparison functions for clarity [RFC,v2,07/22] selinux: use known type instead of void pointer [RFC,v2,08/22] selinux: avoid unnecessary indirection in struct level_datum [RFC,v2,09/22] selinux: make use of str_read() [RFC,v2,10/22] selinux: use u16 for security classes [RFC,v2,11/22] selinux: more strict policy parsing [RFC,v2,12/22] selinux: check length fields in policies [RFC,v2,13/22] selinux: validate constraints [RFC,v2,14/22] selinux: pre-validate conditional expressions [RFC,v2,15/22] selinux: introduce ebitmap_highest_set_bit() [RFC,v2,16/22] selinux: check type attr map overflows [RFC,v2,17/22] selinux: reorder policydb_index() [RFC,v2,18/22] selinux: beef up isvalid checks [RFC,v2,19/22] selinux: validate symbols [RFC,v2,20/22] selinux: more strict bounds check [RFC,v2,21/22] selinux: check for simple types [RFC,v2,22/22] selinux: restrict policy strings

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 2408c3e8ae39..eeca470cc90c 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -927,7 +927,7 @@ int policydb_load_isids(struct policydb *p, struct sidtab *s) return 0; } -int policydb_class_isvalid(struct policydb *p, unsigned int class) +int policydb_class_isvalid(struct policydb *p, u16 class) { if (!class || class > p->p_classes.nprim) return 0; @@ -1321,7 +1321,7 @@ 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; + u32 i, len, len2, ncons, nel, val; int rc; cladatum = kzalloc(sizeof(*cladatum), GFP_KERNEL); @@ -1334,9 +1334,14 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * len = le32_to_cpu(buf[0]); len2 = le32_to_cpu(buf[1]); - cladatum->value = le32_to_cpu(buf[2]); nel = le32_to_cpu(buf[4]); + val = le32_to_cpu(buf[2]); + rc = -EINVAL; + if (val >= U16_MAX) + goto bad; + cladatum->value = val; + rc = symtab_init(&cladatum->permissions, nel); if (rc) goto bad; @@ -1842,7 +1847,7 @@ static int range_read(struct policydb *p, struct policy_file *fp) struct mls_range *r = NULL; int rc; __le32 buf[2]; - u32 i, nel; + u32 i, nel, val; if (p->policyvers < POLICYDB_VERSION_MLS) return 0; @@ -1873,7 +1878,11 @@ static int range_read(struct policydb *p, struct policy_file *fp) rc = next_entry(buf, fp, sizeof(u32)); if (rc) goto out; - rt->target_class = le32_to_cpu(buf[0]); + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val >= U16_MAX) + goto out; + rt->target_class = val; } else rt->target_class = p->process_class; @@ -1918,7 +1927,7 @@ static int filename_trans_read_helper_compat(struct policydb *p, struct policy_f struct filename_trans_key key, *ft = NULL; struct filename_trans_datum *last, *datum = NULL; char *name = NULL; - u32 len, stype, otype; + u32 len, stype, otype, val; __le32 buf[4]; int rc; @@ -1939,7 +1948,11 @@ static int filename_trans_read_helper_compat(struct policydb *p, struct policy_f stype = le32_to_cpu(buf[0]); key.ttype = le32_to_cpu(buf[1]); - key.tclass = le32_to_cpu(buf[2]); + val = le32_to_cpu(buf[2]); + rc = -EINVAL; + if (val > U16_MAX || !policydb_class_isvalid(p, val)) + goto out; + key.tclass = val; key.name = name; otype = le32_to_cpu(buf[3]); @@ -2003,7 +2016,8 @@ static int filename_trans_read_helper(struct policydb *p, struct policy_file *fp struct filename_trans_key *ft = NULL; struct filename_trans_datum **dst, *datum, *first = NULL; char *name = NULL; - u32 len, ttype, tclass, ndatum, i; + u32 len, ttype, ndatum, i, val; + u16 tclass; __le32 buf[3]; int rc; @@ -2023,7 +2037,11 @@ static int filename_trans_read_helper(struct policydb *p, struct policy_file *fp goto out; ttype = le32_to_cpu(buf[0]); - tclass = le32_to_cpu(buf[1]); + val = le32_to_cpu(buf[1]); + rc = -EINVAL; + if (val > U16_MAX || !policydb_class_isvalid(p, val)) + goto out; + tclass = val; ndatum = le32_to_cpu(buf[2]); if (ndatum == 0) { @@ -2131,7 +2149,7 @@ static int filename_trans_read(struct policydb *p, struct policy_file *fp) static int genfs_read(struct policydb *p, struct policy_file *fp) { int rc; - u32 i, j, nel, nel2, len, len2; + u32 i, j, nel, nel2, len, len2, val; __le32 buf[1]; struct ocontext *l, *c; struct ocontext *newc = NULL; @@ -2201,7 +2219,11 @@ static int genfs_read(struct policydb *p, struct policy_file *fp) if (rc) goto out; - newc->v.sclass = le32_to_cpu(buf[0]); + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val >= U16_MAX) + goto out; + newc->v.sclass = val; rc = context_read_and_validate(&newc->context[0], p, fp); if (rc) @@ -2446,7 +2468,7 @@ int policydb_read(struct policydb *p, struct policy_file *fp) struct role_trans_datum *rtd = NULL; int rc; __le32 buf[4]; - u32 i, j, len, nprim, nel, perm; + u32 i, j, len, nprim, nel, perm, val; char *policydb_str; const struct policydb_compat_info *info; @@ -2632,7 +2654,11 @@ int policydb_read(struct policydb *p, struct policy_file *fp) rc = next_entry(buf, fp, sizeof(u32)); if (rc) goto bad; - rtk->tclass = le32_to_cpu(buf[0]); + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val >= U16_MAX) + goto bad; + rtk->tclass = val; } else rtk->tclass = p->process_class; diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index 25650224b6e7..0c423ad77fd9 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -48,7 +48,7 @@ struct common_datum { /* Class attributes */ struct class_datum { - u32 value; /* class value */ + u16 value; /* class value */ char *comkey; /* common name */ struct common_datum *comdatum; /* common datum */ struct symtab permissions; /* class-specific permission symbol table */ @@ -82,7 +82,7 @@ struct role_datum { struct role_trans_key { u32 role; /* current role */ u32 type; /* program executable type, or new object type */ - u32 tclass; /* process class, or new object class */ + u16 tclass; /* process class, or new object class */ }; struct role_trans_datum { @@ -139,7 +139,7 @@ struct cat_datum { struct range_trans { u32 source_type; u32 target_type; - u32 target_class; + u16 target_class; }; /* Boolean data type */ @@ -195,7 +195,7 @@ struct ocontext { } ibendport; } u; union { - u32 sclass; /* security class for genfs */ + u16 sclass; /* security class for genfs */ u32 behavior; /* labeling behavior for fs_use */ } v; struct context context[2]; /* security context(s) */ @@ -320,7 +320,7 @@ struct policy_file { extern void policydb_destroy(struct policydb *p); extern int policydb_load_isids(struct policydb *p, struct sidtab *s); extern int policydb_context_isvalid(struct policydb *p, struct context *c); -extern int policydb_class_isvalid(struct policydb *p, unsigned int class); +extern int policydb_class_isvalid(struct policydb *p, u16 class); extern int policydb_type_isvalid(struct policydb *p, unsigned int type); extern int policydb_role_isvalid(struct policydb *p, unsigned int role); extern int policydb_read(struct policydb *p, struct policy_file *fp); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index e5c9b62e59c1..28c0bdf9fc9d 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -3350,7 +3350,7 @@ static int get_classes_callback(void *k, void *d, void *args) { struct class_datum *datum = d; char *name = k, **classes = args; - u32 value = datum->value - 1; + u16 value = datum->value - 1; classes[value] = kstrdup(name, GFP_ATOMIC); if (!classes[value])

[RFC,v2,10/22] selinux: use u16 for security classes

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