[v39,18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx

Message ID	20231215221636.105680-19-casey@schaufler-ca.com (mailing list archive)
State	New
Delegated to:	Paul Moore
Headers	show Received: from sonic302-28.consmr.mail.ne1.yahoo.com (sonic302-28.consmr.mail.ne1.yahoo.com [66.163.186.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 10F8F18B06 for <linux-security-module@vger.kernel.org>; Fri, 15 Dec 2023 22:31:02 +0000 (UTC) From: Casey Schaufler <casey@schaufler-ca.com> To: casey@schaufler-ca.com, paul@paul-moore.com, linux-security-module@vger.kernel.org Cc: jmorris@namei.org, serge@hallyn.com, keescook@chromium.org, john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp, stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org, mic@digikod.net, netdev@vger.kernel.org, audit@vger.kernel.org, netfilter-devel@vger.kernel.org, Todd Kjos <tkjos@google.com> Subject: [PATCH v39 18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx Date: Fri, 15 Dec 2023 14:16:12 -0800 Message-ID: <20231215221636.105680-19-casey@schaufler-ca.com> In-Reply-To: <20231215221636.105680-1-casey@schaufler-ca.com> References: <20231215221636.105680-1-casey@schaufler-ca.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	LSM: General module stacking \| expand [v39,00/42] LSM: General module stacking [v39,01/42] integrity: disassociate ima_filter_rule from security_audit_rule [v39,02/42] SM: Infrastructure management of the sock security [v39,03/42] LSM: Add the lsmblob data structure. [v39,04/42] IMA: avoid label collisions with stacked LSMs [v39,05/42] LSM: Use lsmblob in security_audit_rule_match [v39,06/42] LSM: Add lsmblob_to_secctx hook [v39,07/42] Audit: maintain an lsmblob in audit_context [v39,08/42] LSM: Use lsmblob in security_ipc_getsecid [v39,09/42] Audit: Update shutdown LSM data [v39,10/42] LSM: Use lsmblob in security_current_getsecid [v39,11/42] LSM: Use lsmblob in security_inode_getsecid [v39,12/42] Audit: use an lsmblob in audit_names [v39,13/42] LSM: Create new security_cred_getlsmblob LSM hook [v39,14/42] Audit: Change context data from secid to lsmblob [v39,15/42] Netlabel: Use lsmblob for audit data [v39,16/42] LSM: Ensure the correct LSM context releaser [v39,17/42] LSM: Use lsmcontext in security_secid_to_secctx [v39,18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx [v39,19/42] LSM: Use lsmcontext in security_inode_getsecctx [v39,20/42] LSM: Use lsmcontext in security_dentry_init_security [v39,21/42] LSM: security_lsmblob_to_secctx module selection [v39,22/42] Audit: Create audit_stamp structure [v39,23/42] Audit: Allow multiple records in an audit_buffer [v39,24/42] Audit: Add record for multiple task security contexts [v39,25/42] audit: multiple subject lsm values for netlabel [v39,26/42] Audit: Add record for multiple object contexts [v39,27/42] LSM: Remove unused lsmcontext_init() [v39,28/42] LSM: Improve logic in security_getprocattr [v39,29/42] LSM: secctx provider check on release [v39,30/42] LSM: Single calls in socket_getpeersec hooks [v39,31/42] LSM: Exclusive secmark usage [v39,32/42] LSM: Identify which LSM handles the context string [v39,33/42] AppArmor: Remove the exclusive flag [v39,34/42] LSM: Add mount opts blob size tracking [v39,35/42] LSM: allocate mnt_opts blobs instead of module specific data [v39,36/42] LSM: Infrastructure management of the key security blob [v39,37/42] LSM: Infrastructure management of the mnt_opts security blob [v39,38/42] LSM: Correct handling of ENOSYS in inode_setxattr [v39,39/42] LSM: Remove lsmblob scaffolding [v39,40/42] LSM: Allow reservation of netlabel [v39,41/42] LSM: restrict security_cred_getsecid() to a single LSM [v39,42/42] Smack: Remove LSM_FLAG_EXCLUSIVE

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 8e0155ac6697..339a4559daf8 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -275,7 +275,7 @@ LSM_HOOK(int, -EINVAL, setprocattr, const char *name, void *value, size_t size) LSM_HOOK(int, 0, ismaclabel, const char *name) LSM_HOOK(int, -EOPNOTSUPP, secid_to_secctx, u32 secid, struct lsmcontext *cp) LSM_HOOK(int, -EOPNOTSUPP, lsmblob_to_secctx, struct lsmblob *blob, - char **secdata, u32 *seclen) + struct lsmcontext *cp) LSM_HOOK(int, 0, secctx_to_secid, const char *secdata, u32 seclen, u32 *secid) LSM_HOOK(void, LSM_RET_VOID, release_secctx, struct lsmcontext *cp) LSM_HOOK(void, LSM_RET_VOID, inode_invalidate_secctx, struct inode *inode) diff --git a/include/linux/security.h b/include/linux/security.h index 03b79089eaf7..2a0615a62125 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -563,8 +563,7 @@ int security_setprocattr(int lsmid, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); int security_secid_to_secctx(u32 secid, struct lsmcontext *cp); -int security_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen); +int security_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp); int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); void security_release_secctx(struct lsmcontext *cp); void security_inode_invalidate_secctx(struct inode *inode); @@ -1493,7 +1492,7 @@ static inline int security_secid_to_secctx(u32 secid, struct lsmcontext *cp) } static inline int security_lsmblob_to_secctx(struct lsmblob *blob, - char **secdata, u32 *seclen) + struct lsmcontext *cp) { return -EOPNOTSUPP; } diff --git a/kernel/audit.c b/kernel/audit.c index 47cfb6b20c3c..a93a710c980e 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1462,9 +1462,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (lsmblob_is_set(&audit_sig_lsm)) { err = security_lsmblob_to_secctx(&audit_sig_lsm, - &lsmctx.context, - &lsmctx.len); - if (err) + &lsmctx); + if (err < 0) return err; } sig_data_size = struct_size(sig_data, ctx, lsmctx.len); @@ -2175,8 +2174,8 @@ int audit_log_task_context(struct audit_buffer *ab) if (!lsmblob_is_set(&blob)) return 0; - error = security_lsmblob_to_secctx(&blob, &ctx.context, &ctx.len); - if (error) { + error = security_lsmblob_to_secctx(&blob, &ctx); + if (error < 0) { if (error != -EINVAL) goto error_path; return 0; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 2874255f5f25..c37cc02ea4cc 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1109,7 +1109,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); if (lsmblob_is_set(blob)) { - if (security_lsmblob_to_secctx(blob, &ctx.context, &ctx.len)) { + if (security_lsmblob_to_secctx(blob, &ctx) < 0) { audit_log_format(ab, " obj=(none)"); rc = 1; } else { @@ -1370,7 +1370,7 @@ static void audit_log_time(struct audit_context *context, struct audit_buffer ** static void show_special(struct audit_context *context, int *call_panic) { - struct lsmcontext lsmcxt; + struct lsmcontext lsmctx; struct audit_buffer *ab; int i; @@ -1393,16 +1393,12 @@ static void show_special(struct audit_context *context, int *call_panic) from_kgid(&init_user_ns, context->ipc.gid), context->ipc.mode); if (lsmblob_is_set(&context->ipc.oblob)) { - char *ctx = NULL; - u32 len; - if (security_lsmblob_to_secctx(&context->ipc.oblob, - &ctx, &len)) { + &lsmctx) < 0) { *call_panic = 1; } else { - audit_log_format(ab, " obj=%s", ctx); - lsmcontext_init(&lsmcxt, ctx, len, 0); - security_release_secctx(&lsmcxt); + audit_log_format(ab, " obj=%s", lsmctx.context); + security_release_secctx(&lsmctx); } } if (context->ipc.has_perm) { @@ -1563,8 +1559,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, if (lsmblob_is_set(&n->oblob)) { struct lsmcontext ctx; - if (security_lsmblob_to_secctx(&n->oblob, &ctx.context, - &ctx.len)) { + if (security_lsmblob_to_secctx(&n->oblob, &ctx) < 0) { if (call_panic) *call_panic = 2; } else { diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index b9289a22b363..561e1e476a49 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -98,8 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type, audit_info->sessionid); if (lsmblob_is_set(&audit_info->blob) && - security_lsmblob_to_secctx(&audit_info->blob, &ctx.context, - &ctx.len) == 0) { + security_lsmblob_to_secctx(&audit_info->blob, &ctx) >= 0) { audit_log_format(audit_buf, " subj=%s", ctx.context); security_release_secctx(&ctx); } diff --git a/security/apparmor/include/secid.h b/security/apparmor/include/secid.h index b66c2d043a02..568820a11efc 100644 --- a/security/apparmor/include/secid.h +++ b/security/apparmor/include/secid.h @@ -26,8 +26,7 @@ extern int apparmor_display_secid_mode; struct aa_label *aa_secid_to_label(u32 secid); int apparmor_secid_to_secctx(u32 secid, struct lsmcontext *cp); -int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen); +int apparmor_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp); int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); void apparmor_release_secctx(struct lsmcontext *cp); diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c index 55d6c54fe90e..c9b9a8d90afa 100644 --- a/security/apparmor/secid.c +++ b/security/apparmor/secid.c @@ -93,8 +93,7 @@ int apparmor_secid_to_secctx(u32 secid, struct lsmcontext *cp) return len; } -int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen) +int apparmor_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp) { /* TODO: cache secctx and ref count so we don't have to recreate */ struct aa_label *label; @@ -115,8 +114,8 @@ int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, if (apparmor_display_secid_mode) flags |= FLAG_SHOW_MODE; - if (secdata) - len = aa_label_asxprint(secdata, root_ns, label, + if (cp) + len = aa_label_asxprint(&cp->context, root_ns, label, flags, GFP_ATOMIC); else len = aa_label_snxprint(NULL, 0, root_ns, label, flags); @@ -124,9 +123,12 @@ int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, if (len < 0) return -ENOMEM; - *seclen = len; + if (cp) { + cp->len = len; + cp->id = LSM_ID_APPARMOR; + } - return 0; + return len; } int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) diff --git a/security/security.c b/security/security.c index 708a26a88447..e070a6cd4089 100644 --- a/security/security.c +++ b/security/security.c @@ -4203,30 +4203,28 @@ EXPORT_SYMBOL(security_secid_to_secctx); /** * security_lsmblob_to_secctx() - Convert a lsmblob to a secctx * @blob: lsm specific information - * @secdata: secctx - * @seclen: secctx length + * @cp: the LSM context * - * Convert a @blob entry to security context. If @secdata is NULL the - * length of the result will be returned in @seclen, but no @secdata - * will be returned. This does mean that the length could change between - * calls to check the length and the next call which actually allocates - * and returns the @secdata. + * Convert a @blob entry to security context. If @cp is NULL the + * length of the result will be returned, but no data will be returned. + * This does mean that the length could change between calls to check + * the length and the next call which actually allocates and returns + * the data. * - * Return: Return 0 on success, error on failure. + * Return: Return length of data on success, error on failure. */ -int security_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen) +int security_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp) { struct security_hook_list *hp; int rc; hlist_for_each_entry(hp, &security_hook_heads.lsmblob_to_secctx, list) { - rc = hp->hook.lsmblob_to_secctx(blob, secdata, seclen); - if (rc != LSM_RET_DEFAULT(secid_to_secctx)) + rc = hp->hook.lsmblob_to_secctx(blob, cp); + if (rc != LSM_RET_DEFAULT(lsmblob_to_secctx)) return rc; } - return LSM_RET_DEFAULT(secid_to_secctx); + return LSM_RET_DEFAULT(lsmblob_to_secctx); } EXPORT_SYMBOL(security_lsmblob_to_secctx); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 37b97cf81da1..d138aa692abd 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6583,16 +6583,28 @@ static int selinux_secid_to_secctx(u32 secid, struct lsmcontext *cp) return seclen; } -static int selinux_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen) +static int selinux_lsmblob_to_secctx(struct lsmblob *blob, + struct lsmcontext *cp) { u32 secid = blob->selinux.secid; + u32 seclen; + u32 ret; /* stacking scaffolding */ if (!secid) secid = blob->scaffold.secid; - return security_sid_to_context(secid, secdata, seclen); + if (cp) { + cp->id = LSM_ID_SELINUX; + ret = security_sid_to_context(secid, &cp->context, &cp->len); + if (ret < 0) + return ret; + return cp->len; + } + ret = security_sid_to_context(secid, NULL, &seclen); + if (ret < 0) + return ret; + return seclen; } static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index d82753bc52ab..1fdd4233a9b3 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4839,19 +4839,23 @@ static int smack_secid_to_secctx(u32 secid, struct lsmcontext *cp) * * Exists for audit code. */ -static int smack_lsmblob_to_secctx(struct lsmblob *blob, char **secdata, - u32 *seclen) +static int smack_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp) { struct smack_known *skp = blob->smack.skp; + int len; /* stacking scaffolding */ if (!skp && blob->scaffold.secid) skp = smack_from_secid(blob->scaffold.secid); - if (secdata) - *secdata = skp->smk_known; - *seclen = strlen(skp->smk_known); - return 0; + len = strlen(skp->smk_known); + + if (cp) { + cp->context = skp->smk_known; + cp->len = len; + cp->id = LSM_ID_SMACK; + } + return len; } /**

[v39,18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx

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Patch