[v33,15/29] LSM: Ensure the correct LSM context releaser

Message ID	20220310234632.16194-16-casey@schaufler-ca.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> From: Casey Schaufler <casey@schaufler-ca.com> To: casey.schaufler@intel.com, jmorris@namei.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Cc: casey@schaufler-ca.com, linux-audit@redhat.com, keescook@chromium.org, john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com, stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org, Chuck Lever <chuck.lever@oracle.com>, linux-integrity@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH v33 15/29] LSM: Ensure the correct LSM context releaser Date: Thu, 10 Mar 2022 15:46:18 -0800 Message-Id: <20220310234632.16194-16-casey@schaufler-ca.com> In-Reply-To: <20220310234632.16194-1-casey@schaufler-ca.com> References: <20220310234632.16194-1-casey@schaufler-ca.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	LSM: Module stacking for AppArmor \| expand [v33,00/29] LSM: Module stacking for AppArmor [v33,01/29] integrity: disassociate ima_filter_rule from security_audit_rule [v33,02/29] LSM: Infrastructure management of the sock security [v33,03/29] LSM: Add the lsmblob data structure. [v33,04/29] LSM: provide lsm name and id slot mappings [v33,05/29] IMA: avoid label collisions with stacked LSMs [v33,06/29] LSM: Use lsmblob in security_audit_rule_match [v33,07/29] LSM: Use lsmblob in security_kernel_act_as [v33,08/29] LSM: Use lsmblob in security_secctx_to_secid [v33,09/29] LSM: Use lsmblob in security_secid_to_secctx [v33,10/29] LSM: Use lsmblob in security_ipc_getsecid [v33,11/29] LSM: Use lsmblob in security_current_getsecid [v33,12/29] LSM: Use lsmblob in security_inode_getsecid [v33,13/29] LSM: Use lsmblob in security_cred_getsecid [v33,14/29] LSM: Specify which LSM to display [v33,15/29] LSM: Ensure the correct LSM context releaser [v33,16/29] LSM: Use lsmcontext in security_secid_to_secctx [v33,17/29] LSM: Use lsmcontext in security_inode_getsecctx [v33,18/29] LSM: security_secid_to_secctx in netlink netfilter [v33,19/29] NET: Store LSM netlabel data in a lsmblob [v33,20/29] binder: Pass LSM identifier for confirmation [v33,21/29] LSM: Extend security_secid_to_secctx to include module selection [v33,22/29] Audit: Keep multiple LSM data in audit_names [v33,23/29] Audit: Create audit_stamp structure [v33,24/29] LSM: Add a function to report multiple LSMs [v33,25/29] Audit: Allow multiple records in an audit_buffer [v33,26/29] Audit: Add record for multiple task security contexts [v33,27/29] Audit: Add record for multiple object security contexts [v33,28/29] LSM: Add /proc attr entry for full LSM context [v33,29/29] AppArmor: Remove the exclusive flag

diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 26838061defb..2125b4b795da 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2725,6 +2725,7 @@ static void binder_transaction(struct binder_proc *proc, int t_debug_id = atomic_inc_return(&binder_last_id); char *secctx = NULL; u32 secctx_sz = 0; + struct lsmcontext scaff; /* scaffolding */ struct list_head sgc_head; struct list_head pf_head; const void __user *user_buffer = (const void __user *) @@ -3033,7 +3034,8 @@ static void binder_transaction(struct binder_proc *proc, t->security_ctx = 0; WARN_ON(1); } - security_release_secctx(secctx, secctx_sz); + lsmcontext_init(&scaff, secctx, secctx_sz, 0); + security_release_secctx(&scaff); secctx = NULL; } t->buffer->debug_id = t->debug_id; @@ -3433,8 +3435,10 @@ static void binder_transaction(struct binder_proc *proc, binder_alloc_free_buf(&target_proc->alloc, t->buffer); err_binder_alloc_buf_failed: err_bad_extra_size: - if (secctx) - security_release_secctx(secctx, secctx_sz); + if (secctx) { + lsmcontext_init(&scaff, secctx, secctx_sz, 0); + security_release_secctx(&scaff); + } err_get_secctx_failed: kfree(tcomplete); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index fcf7dfdecf96..df2b3bf46364 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -1374,12 +1374,16 @@ int ceph_security_init_secctx(struct dentry *dentry, umode_t mode, void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx) { +#ifdef CONFIG_CEPH_FS_SECURITY_LABEL + struct lsmcontext scaff; /* scaffolding */ +#endif #ifdef CONFIG_CEPH_FS_POSIX_ACL posix_acl_release(as_ctx->acl); posix_acl_release(as_ctx->default_acl); #endif #ifdef CONFIG_CEPH_FS_SECURITY_LABEL - security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen); + lsmcontext_init(&scaff, as_ctx->sec_ctx, as_ctx->sec_ctxlen, 0); + security_release_secctx(&scaff); #endif if (as_ctx->pagelist) ceph_pagelist_release(as_ctx->pagelist); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b18f31b2c9e7..c6237b5ddd93 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -133,8 +133,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry, static inline void nfs4_label_release_security(struct nfs4_label *label) { - if (label) - security_release_secctx(label->label, label->len); + struct lsmcontext scaff; /* scaffolding */ + + if (label) { + lsmcontext_init(&scaff, label->label, label->len, 0); + security_release_secctx(&scaff); + } } static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 899de438e529..fedc4b0292d6 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2830,6 +2830,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, int err; struct nfs4_acl *acl = NULL; #ifdef CONFIG_NFSD_V4_SECURITY_LABEL + struct lsmcontext scaff; /* scaffolding */ void *context = NULL; int contextlen; #endif @@ -3331,8 +3332,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, out: #ifdef CONFIG_NFSD_V4_SECURITY_LABEL - if (context) - security_release_secctx(context, contextlen); + if (context) { + lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/ + security_release_secctx(&scaff); + } #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); if (tempfh) { diff --git a/include/linux/security.h b/include/linux/security.h index 9753bd9b4fdc..11c4d088f7a8 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -135,6 +135,37 @@ enum lockdown_reason { extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; +/* + * A "security context" is the text representation of + * the information used by LSMs. + * This structure contains the string, its length, and which LSM + * it is useful for. + */ +struct lsmcontext { + char *context; /* Provided by the module */ + u32 len; + int slot; /* Identifies the module */ +}; + +/** + * lsmcontext_init - initialize an lsmcontext structure. + * @cp: Pointer to the context to initialize + * @context: Initial context, or NULL + * @size: Size of context, or 0 + * @slot: Which LSM provided the context + * + * Fill in the lsmcontext from the provided information. + * This is a scaffolding function that will be removed when + * lsmcontext integration is complete. + */ +static inline void lsmcontext_init(struct lsmcontext *cp, char *context, + u32 size, int slot) +{ + cp->slot = slot; + cp->context = context; + cp->len = size; +} + /* * Data exported by the security modules * @@ -569,7 +600,7 @@ int security_ismaclabel(const char *name); int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob); -void security_release_secctx(char *secdata, u32 seclen); +void security_release_secctx(struct lsmcontext *cp); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); @@ -1432,7 +1463,7 @@ static inline int security_secctx_to_secid(const char *secdata, return -EOPNOTSUPP; } -static inline void security_release_secctx(char *secdata, u32 seclen) +static inline void security_release_secctx(struct lsmcontext *cp) { } diff --git a/include/net/scm.h b/include/net/scm.h index 23a35ff1b3f2..f273c4d777ec 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, #ifdef CONFIG_SECURITY_NETWORK static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { + struct lsmcontext context; struct lsmblob lb; char *secdata; u32 seclen; @@ -106,7 +107,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc if (!err) { put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); - security_release_secctx(secdata, seclen); + /*scaffolding*/ + lsmcontext_init(&context, secdata, seclen, 0); + security_release_secctx(&context); } } } diff --git a/kernel/audit.c b/kernel/audit.c index c7cd039e258b..5aa2ee06c9e4 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1190,6 +1190,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct audit_sig_info *sig_data; char *ctx = NULL; u32 len; + struct lsmcontext scaff; /* scaffolding */ err = audit_netlink_ok(skb, msg_type); if (err) @@ -1447,15 +1448,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL); if (!sig_data) { - if (lsmblob_is_set(&audit_sig_lsm)) - security_release_secctx(ctx, len); + if (lsmblob_is_set(&audit_sig_lsm)) { + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); + } return -ENOMEM; } sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); sig_data->pid = audit_sig_pid; if (lsmblob_is_set(&audit_sig_lsm)) { memcpy(sig_data->ctx, ctx, len); - security_release_secctx(ctx, len); + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); } audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, sig_data, struct_size(sig_data, ctx, len)); @@ -2147,6 +2151,7 @@ int audit_log_task_context(struct audit_buffer *ab) unsigned len; int error; struct lsmblob blob; + struct lsmcontext scaff; /* scaffolding */ security_current_getsecid_subj(&blob); if (!lsmblob_is_set(&blob)) @@ -2161,7 +2166,8 @@ int audit_log_task_context(struct audit_buffer *ab) } audit_log_format(ab, " subj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); return 0; error_path: diff --git a/kernel/auditsc.c b/kernel/auditsc.c index c4c3666576c3..1626d8aabe83 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1121,6 +1121,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, struct lsmblob *blob, char *comm) { struct audit_buffer *ab; + struct lsmcontext lsmcxt; char *ctx = NULL; u32 len; int rc = 0; @@ -1138,7 +1139,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, rc = 1; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/ + security_release_secctx(&lsmcxt); } } audit_log_format(ab, " ocomm="); @@ -1351,6 +1353,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) static void show_special(struct audit_context *context, int *call_panic) { + struct lsmcontext lsmcxt; struct audit_buffer *ab; int i; @@ -1385,7 +1388,8 @@ static void show_special(struct audit_context *context, int *call_panic) *call_panic = 1; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); + security_release_secctx(&lsmcxt); } } if (context->ipc.has_perm) { @@ -1542,6 +1546,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, char *ctx = NULL; u32 len; struct lsmblob blob; + struct lsmcontext lsmcxt; lsmblob_init(&blob, n->osid); if (security_secid_to_secctx(&blob, &ctx, &len)) { @@ -1550,7 +1555,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, *call_panic = 2; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */ + security_release_secctx(&lsmcxt); } } diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 933a8f94f93a..70ca4510ea35 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { + struct lsmcontext context; struct lsmblob lb; char *secdata; u32 seclen, secid; @@ -145,7 +146,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) return; put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata); - security_release_secctx(secdata, seclen); + lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */ + security_release_secctx(&context); } static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 073510c94b56..212e12b53adb 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -342,6 +342,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) int len, ret; char *secctx; struct lsmblob blob; + struct lsmcontext context; /* lsmblob_init() puts ct->secmark into all of the secids in blob. * security_secid_to_secctx() will know which security module @@ -362,7 +363,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) ret = 0; nla_put_failure: - security_release_secctx(secctx, len); + lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ + security_release_secctx(&context); return ret; } #else diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index bba3a66f5636..3b6ba86783f6 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -179,6 +179,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) u32 len; char *secctx; struct lsmblob blob; + struct lsmcontext context; lsmblob_init(&blob, ct->secmark); ret = security_secid_to_secctx(&blob, &secctx, &len); @@ -187,7 +188,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) seq_printf(s, "secctx=%s ", secctx); - security_release_secctx(secctx, len); + lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ + security_release_secctx(&context); } #else static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index a9f7c9418ad3..d986bae1587b 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -397,6 +397,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, enum ip_conntrack_info ctinfo = 0; const struct nfnl_ct_hook *nfnl_ct; bool csum_verify; + struct lsmcontext scaff; /* scaffolding */ char *secdata = NULL; u32 seclen = 0; @@ -627,8 +628,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } nlh->nlmsg_len = skb->len; - if (seclen) - security_release_secctx(secdata, seclen); + if (seclen) { + lsmcontext_init(&scaff, secdata, seclen, 0); + security_release_secctx(&scaff); + } return skb; nla_put_failure: @@ -636,8 +639,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); nlmsg_failure: - if (seclen) - security_release_secctx(secdata, seclen); + if (seclen) { + lsmcontext_init(&scaff, secdata, seclen, 0); + security_release_secctx(&scaff); + } return NULL; } diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index c86df6ead742..a8e9ee202245 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -374,6 +374,7 @@ int netlbl_unlhsh_add(struct net *net, struct net_device *dev; struct netlbl_unlhsh_iface *iface; struct audit_buffer *audit_buf = NULL; + struct lsmcontext context; char *secctx = NULL; u32 secctx_len; struct lsmblob blob; @@ -447,7 +448,9 @@ int netlbl_unlhsh_add(struct net *net, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); @@ -478,6 +481,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, struct netlbl_unlhsh_addr4 *entry; struct audit_buffer *audit_buf; struct net_device *dev; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -508,7 +512,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); @@ -545,6 +551,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, struct netlbl_unlhsh_addr6 *entry; struct audit_buffer *audit_buf; struct net_device *dev; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -574,7 +581,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); @@ -1093,6 +1101,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, int ret_val = -ENOMEM; struct netlbl_unlhsh_walk_arg *cb_arg = arg; struct net_device *dev; + struct lsmcontext context; void *data; u32 secid; char *secctx; @@ -1163,7 +1172,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, NLBL_UNLABEL_A_SECCTX, secctx_len, secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); if (ret_val != 0) goto list_cb_failure; diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index 893301ae0131..ef139d8ae7cd 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -84,6 +84,7 @@ struct audit_buffer *netlbl_audit_start_common(int type, struct netlbl_audit *audit_info) { struct audit_buffer *audit_buf; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -103,7 +104,8 @@ struct audit_buffer *netlbl_audit_start_common(int type, if (audit_info->secid != 0 && security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " subj=%s", secctx); - security_release_secctx(secctx, secctx_len); + lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/ + security_release_secctx(&context); } return audit_buf; diff --git a/security/security.c b/security/security.c index 0bca482166d8..163cf0ae2429 100644 --- a/security/security.c +++ b/security/security.c @@ -2366,16 +2366,17 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, } EXPORT_SYMBOL(security_secctx_to_secid); -void security_release_secctx(char *secdata, u32 seclen) +void security_release_secctx(struct lsmcontext *cp) { struct security_hook_list *hp; - int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list) - if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) { - hp->hook.release_secctx(secdata, seclen); - return; + if (cp->slot == hp->lsmid->slot) { + hp->hook.release_secctx(cp->context, cp->len); + break; } + + memset(cp, 0, sizeof(*cp)); } EXPORT_SYMBOL(security_release_secctx);

[v33,15/29] LSM: Ensure the correct LSM context releaser

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Patch