From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from pdx1-mailman-customer002.dreamhost.com (listserver-buz.dreamhost.com [69.163.136.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B81E3C25B50 for ; Mon, 23 Jan 2023 23:27:31 +0000 (UTC) Received: from pdx1-mailman-customer002.dreamhost.com (localhost [127.0.0.1]) by pdx1-mailman-customer002.dreamhost.com (Postfix) with ESMTP id 4P15Ph20blz22T8; Mon, 23 Jan 2023 15:08:40 -0800 (PST) Received: from smtp3.ccs.ornl.gov (smtp3.ccs.ornl.gov [160.91.203.39]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pdx1-mailman-customer002.dreamhost.com (Postfix) with ESMTPS id 4P15NR0f3Bz22Pn for ; Mon, 23 Jan 2023 15:07:35 -0800 (PST) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp3.ccs.ornl.gov (Postfix) with ESMTP id 94830B9D; Mon, 23 Jan 2023 18:00:58 -0500 (EST) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 91F1458987; Mon, 23 Jan 2023 18:00:58 -0500 (EST) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Mon, 23 Jan 2023 18:00:44 -0500 Message-Id: <1674514855-15399-32-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1674514855-15399-1-git-send-email-jsimmons@infradead.org> References: <1674514855-15399-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 31/42] lustre: llite: replace selinux_is_enabled() X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Etienne AUJAMES , Lustre Development List MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Etienne AUJAMES selinux_is_enabled() was removed from kernel 5.1. The commit 7037720 add the kernel support by assuming SELinux to be enabled if the function selinux_is_enabled() does not exist. This has performances impacts: getxattr RPCs was not send for "security.selinux" if selinux was disabled. Utilities like "ls -l" always try to get "security.selinux". See the LU-549 for more information. This patch uses security_inode_listsecurity() when mounting the client to know if a LSM module (selinux) required a xattr to store file contexts. If a xattr is returned we store it and use it for in request security context. For getxattr/setxattr we use the stored LSM's xattr to filter xattr security contexts like security.selinux. If xattr does not match the stored xattr name we returned -EOPNOTSUPP to userspace. It adds also the s_security check for security_inode_notifysecctx() to avoid calling this function if selinux is disabled (as in nfs_setsecurity()). For "Enforcing SELinux Policy Check" functionality, the selinux check have been moved in l_getsepol: -ENODEV is returned if selinux is disabled. *Note:* This patch detects that selinux is disabled without explicitly disabled it in kernel cmdline. *Performances:* Tests with "strace -c ls -l" with 100000 files on root in a multi VMs env (on Rocky 9). FS is remount for each tests (cache is cleaned) and selinux is disabled. __________________ ___________ _________ | Total time % | lgetxattr | statx | |__________________|___________|_________| |Without the patch:| 29% | 51% | |__________________|___________|_________| |With the patch: | 0% | 87% | |__________________|___________|_________| "ls -l" uses lgetxattr to get "security.selinux". Linux-commit: 3d252529480c68bfd6a6774652df7c8968b28e41 Fixes: 7037720 ("lustre: remove use of selinux_is_enabled().") WC-bug-id: https://jira.whamcloud.com/browse/LU-16210 Lustre-commit: 1d8faaf6caf4acaf0 ("LU-16210 llite: replace selinux_is_enabled()") Signed-off-by: Etienne AUJAMES Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48875 Reviewed-by: Andreas Dilger Reviewed-by: Sebastien Buisson Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/llite/dir.c | 22 ++-- fs/lustre/llite/llite_internal.h | 46 +++++++- fs/lustre/llite/llite_lib.c | 11 ++ fs/lustre/llite/namei.c | 87 +++++--------- fs/lustre/llite/xattr.c | 10 +- fs/lustre/llite/xattr_cache.c | 6 +- fs/lustre/llite/xattr_security.c | 193 ++++++++++++++++++++++++------- fs/lustre/ptlrpc/sec.c | 17 +-- 8 files changed, 260 insertions(+), 132 deletions(-) diff --git a/fs/lustre/llite/dir.c b/fs/lustre/llite/dir.c index abbba964103f..7dca0fc461c0 100644 --- a/fs/lustre/llite/dir.c +++ b/fs/lustre/llite/dir.c @@ -432,6 +432,7 @@ static int ll_dir_setdirstripe(struct dentry *dparent, struct lmv_user_md *lump, .hash = full_name_hash(dparent, dirname, strlen(dirname)), }, + .d_sb = dparent->d_sb, }; bool encrypt = false; int hash_flags; @@ -511,14 +512,13 @@ static int ll_dir_setdirstripe(struct dentry *dparent, struct lmv_user_md *lump, } if (test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags)) { - /* - * selinux_dentry_init_security() uses dentry->d_parent and name + /* selinux_dentry_init_security() uses dentry->d_parent and name * to determine the security context for the file. So our fake * dentry should be real enough for this purpose. */ - err = ll_dentry_init_security(parent, - &dentry, mode, &dentry.d_name, + err = ll_dentry_init_security(&dentry, mode, &dentry.d_name, &op_data->op_file_secctx_name, + &op_data->op_file_secctx_name_size, &op_data->op_file_secctx, &op_data->op_file_secctx_size); if (err < 0) @@ -550,17 +550,11 @@ static int ll_dir_setdirstripe(struct dentry *dparent, struct lmv_user_md *lump, dentry.d_inode = inode; - if (test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags)) { - /* no need to protect selinux_inode_setsecurity() by - * inode_lock. Taking it would lead to a client deadlock - * LU-13617 - */ - err = security_inode_notifysecctx(inode, - op_data->op_file_secctx, - op_data->op_file_secctx_size); - } else { + if (test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags)) + err = ll_inode_notifysecctx(inode, op_data->op_file_secctx, + op_data->op_file_secctx_size); + else err = ll_inode_init_security(&dentry, inode, parent); - } if (encrypt) err = ll_set_encflags(inode, op_data->op_file_encctx, diff --git a/fs/lustre/llite/llite_internal.h b/fs/lustre/llite/llite_internal.h index 998eed83738e..c42330e54874 100644 --- a/fs/lustre/llite/llite_internal.h +++ b/fs/lustre/llite/llite_internal.h @@ -447,15 +447,45 @@ static inline void obd_connect_set_secctx(struct obd_connect_data *data) #endif } -int ll_dentry_init_security(struct inode *parent, struct dentry *dentry, - int mode, struct qstr *name, - const char **secctx_name, void **secctx, - u32 *secctx_size); +/* Only smack and selinux is known to use security contexts */ +static inline bool ll_xattr_is_seclabel(const char *name) +{ + return !strcmp(name, XATTR_NAME_SELINUX) || + !strcmp(name, XATTR_NAME_SMACK); +} + +static inline bool ll_xattr_suffix_is_seclabel(const char *suffix) +{ + return !strcmp(suffix, XATTR_SELINUX_SUFFIX) || + !strcmp(suffix, XATTR_SMACK_SUFFIX); +} + +int ll_dentry_init_security(struct dentry *dentry, int mode, struct qstr *name, + const char **secctx_name, u32 *secctx_name_size, + void **secctx, u32 *secctx_size); int ll_inode_init_security(struct dentry *dentry, struct inode *inode, struct inode *dir); -int ll_listsecurity(struct inode *inode, char *secctx_name, - size_t secctx_name_size); +int ll_inode_notifysecctx(struct inode *inode, + void *secctx, u32 secctxlen); + +void ll_secctx_name_free(struct ll_sb_info *sbi); + +int ll_secctx_name_store(struct inode *in); + +u32 ll_secctx_name_get(struct ll_sb_info *sbi, const char **secctx_name); + +int ll_security_secctx_name_filter(struct ll_sb_info *sbi, int xattr_type, + const char *suffix); + +static inline bool ll_security_xattr_wanted(struct inode *in) +{ +#ifdef CONFIG_SECURITY + return in->i_security && in->i_sb->s_security; +#else + return false; +#endif +} static inline bool obd_connect_has_enc(struct obd_connect_data *data) { @@ -804,6 +834,10 @@ struct ll_sb_info { struct ll_foreign_symlink_upcall_item *ll_foreign_symlink_upcall_items; /* foreign symlink path upcall nb infos */ unsigned int ll_foreign_symlink_upcall_nb_items; + + /* cached file security context xattr name. e.g: security.selinux */ + char *ll_secctx_name; + u32 ll_secctx_name_size; }; #define SBI_DEFAULT_HEAT_DECAY_WEIGHT ((80 * 256 + 50) / 100) diff --git a/fs/lustre/llite/llite_lib.c b/fs/lustre/llite/llite_lib.c index 176e61b5874e..4bc91dddb6a7 100644 --- a/fs/lustre/llite/llite_lib.c +++ b/fs/lustre/llite/llite_lib.c @@ -144,6 +144,9 @@ static struct ll_sb_info *ll_init_sbi(void) * not enabled by default */ + sbi->ll_secctx_name = NULL; + sbi->ll_secctx_name_size = 0; + sbi->ll_ra_info.ra_max_pages = min(pages / 32, SBI_DEFAULT_READ_AHEAD_MAX); sbi->ll_ra_info.ra_max_pages_per_file = @@ -236,6 +239,8 @@ static void ll_free_sbi(struct super_block *sb) kvfree(items); sbi->ll_foreign_symlink_upcall_items = NULL; } + ll_secctx_name_free(sbi); + ll_free_rw_stats_info(sbi); pcc_super_fini(&sbi->ll_pcc_super); kfree(sbi); @@ -710,6 +715,12 @@ static int client_common_fill_super(struct super_block *sb, char *md, char *dt) goto out_root; } + err = ll_secctx_name_store(root); + if (err < 0 && ll_security_xattr_wanted(root)) + CWARN("%s: file security contextes not supported: rc = %d\n", + sbi->ll_fsname, err); + + err = 0; if (encctxlen) { CDEBUG(D_SEC, "server returned encryption ctx for root inode "DFID"\n", diff --git a/fs/lustre/llite/namei.c b/fs/lustre/llite/namei.c index f23d3ae49fae..9314a1704146 100644 --- a/fs/lustre/llite/namei.c +++ b/fs/lustre/llite/namei.c @@ -712,20 +712,8 @@ static int ll_lookup_it_finish(struct ptlrpc_request *request, PFID(ll_inode2fid(inode))); } - if (secctx && secctxlen != 0) { - /* no need to protect selinux_inode_setsecurity() by - * inode_lock. Taking it would lead to a client deadlock - * LU-13617 - */ - rc = security_inode_notifysecctx(inode, secctx, - secctxlen); - if (rc) - CWARN("%s: cannot set security context for " DFID ": rc = %d\n", - ll_i2sbi(inode)->ll_fsname, - PFID(ll_inode2fid(inode)), - rc); - } - + /* resume normally on error */ + ll_inode_notifysecctx(inode, secctx, secctxlen); } alias = ll_splice_alias(inode, *de); @@ -798,26 +786,26 @@ static int ll_lookup_it_finish(struct ptlrpc_request *request, } static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry, - struct lookup_intent *it, void **secctx, - u32 *secctxlen, + struct lookup_intent *it, + void **secctx, u32 *secctxlen, struct pcc_create_attach *pca, bool encrypt, void **encctx, u32 *encctxlen) { ktime_t kstart = ktime_get(); struct lookup_intent lookup_it = { .it_op = IT_LOOKUP }; + struct ll_sb_info *sbi = ll_i2sbi(parent); struct dentry *save = dentry, *retval; struct ptlrpc_request *req = NULL; struct md_op_data *op_data = NULL; struct lov_user_md *lum = NULL; - char secctx_name[XATTR_NAME_MAX + 1]; struct fscrypt_name fname; struct inode *inode; struct lu_fid fid; u32 opc; int rc; - if (dentry->d_name.len > ll_i2sbi(parent)->ll_namelen) + if (dentry->d_name.len > sbi->ll_namelen) return ERR_PTR(-ENAMETOOLONG); CDEBUG(D_VFSTRACE, "VFS Op:name=%pd, dir=" DFID "(%p),intent=%s\n", @@ -831,13 +819,8 @@ static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry, if (it->it_op == IT_GETATTR && dentry_may_statahead(parent, dentry)) { rc = ll_revalidate_statahead(parent, &dentry, 0); - if (rc == 1) { - if (dentry == save) - retval = NULL; - else - retval = dentry; - goto out; - } + if (rc == 1) + return dentry == save ? NULL : dentry; } if (it->it_op & IT_OPEN && it->it_flags & FMODE_WRITE && @@ -872,7 +855,6 @@ static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry, if (IS_ERR(op_data)) { fscrypt_free_filename(&fname); return ERR_CAST(op_data); - goto out; } if (!fid_is_zero(&fid)) { op_data->op_fid2 = fid; @@ -886,11 +868,11 @@ static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry, it->it_create_mode &= ~current_umask(); if (it->it_op & IT_CREAT && - test_bit(LL_SBI_FILE_SECCTX, ll_i2sbi(parent)->ll_flags)) { - rc = ll_dentry_init_security(parent, - dentry, it->it_create_mode, + test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags)) { + rc = ll_dentry_init_security(dentry, it->it_create_mode, &dentry->d_name, &op_data->op_file_secctx_name, + &op_data->op_file_secctx_name_size, &op_data->op_file_secctx, &op_data->op_file_secctx_size); if (rc < 0) { @@ -993,22 +975,12 @@ static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry, *encctxlen = 0; } - /* ask for security context upon intent */ - if (it->it_op & (IT_LOOKUP | IT_GETATTR | IT_OPEN)) { - /* get name of security xattr to request to server */ - rc = ll_listsecurity(parent, secctx_name, - sizeof(secctx_name)); - if (rc < 0) { - CDEBUG(D_SEC, - "cannot get security xattr name for " DFID ": rc = %d\n", - PFID(ll_inode2fid(parent)), rc); - } else if (rc > 0) { - op_data->op_file_secctx_name = secctx_name; - op_data->op_file_secctx_name_size = rc; - CDEBUG(D_SEC, "'%.*s' is security xattr for " DFID "\n", - rc, secctx_name, PFID(ll_inode2fid(parent))); - } - } + /* ask for security context upon intent: + * get name of security xattr to request to server + */ + if (it->it_op & (IT_LOOKUP | IT_GETATTR | IT_OPEN)) + op_data->op_file_secctx_name_size = + ll_secctx_name_get(sbi, &op_data->op_file_secctx_name); if (pca && pca->pca_dataset) { lum = kzalloc(sizeof(*lum), GFP_NOFS); @@ -1416,20 +1388,13 @@ static int ll_create_it(struct inode *dir, struct dentry *dentry, if (IS_ERR(inode)) return PTR_ERR(inode); - if (test_bit(LL_SBI_FILE_SECCTX, ll_i2sbi(inode)->ll_flags) && - secctx) { - /* must be done before d_instantiate, because it calls - * security_d_instantiate, which means a getxattr if security - * context is not set yet - */ - /* no need to protect selinux_inode_setsecurity() by - * inode_lock. Taking it would lead to a client deadlock - * LU-13617 - */ - rc = security_inode_notifysecctx(inode, secctx, secctxlen); - if (rc) - return rc; - } + /* must be done before d_instantiate, because it calls + * security_d_instantiate, which means a getxattr if security + * context is not set yet + */ + rc = ll_inode_notifysecctx(inode, secctx, secctxlen); + if (rc) + return rc; d_instantiate(dentry, inode); @@ -1567,9 +1532,9 @@ static int ll_new_node(struct inode *dir, struct dentry *dchild, ll_qos_mkdir_prep(op_data, dir); if (test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags)) { - err = ll_dentry_init_security(dir, - dchild, mode, &dchild->d_name, + err = ll_dentry_init_security(dchild, mode, &dchild->d_name, &op_data->op_file_secctx_name, + &op_data->op_file_secctx_name_size, &op_data->op_file_secctx, &op_data->op_file_secctx_size); if (err < 0) diff --git a/fs/lustre/llite/xattr.c b/fs/lustre/llite/xattr.c index 11310f9a0a6b..c90f5017c931 100644 --- a/fs/lustre/llite/xattr.c +++ b/fs/lustre/llite/xattr.c @@ -123,6 +123,10 @@ static int ll_xattr_set_common(const struct xattr_handler *handler, (!strcmp(name, "ima") || !strcmp(name, "evm"))) return -EOPNOTSUPP; + rc = ll_security_secctx_name_filter(sbi, handler->flags, name); + if (rc) + return rc; + /* * In user.* namespace, only regular files and directories can have * extended attributes. @@ -373,7 +377,7 @@ int ll_xattr_list(struct inode *inode, const char *name, int type, void *buffer, } if (sbi->ll_xattr_cache_enabled && type != XATTR_ACL_ACCESS_T && - (type != XATTR_SECURITY_T || strcmp(name, "security.selinux")) && + (type != XATTR_SECURITY_T || !ll_xattr_is_seclabel(name)) && (type != XATTR_TRUSTED_T || strcmp(name, XATTR_NAME_SOM))) { rc = ll_xattr_cache_get(inode, name, buffer, size, valid); if (rc == -EAGAIN) @@ -448,6 +452,10 @@ static int ll_xattr_get_common(const struct xattr_handler *handler, if (rc) return rc; + rc = ll_security_secctx_name_filter(sbi, handler->flags, name); + if (rc) + return rc; + #ifdef CONFIG_LUSTRE_FS_POSIX_ACL /* posix acl is under protection of LOOKUP lock. when calling to this, * we just have path resolution to the target inode, so we have great diff --git a/fs/lustre/llite/xattr_cache.c b/fs/lustre/llite/xattr_cache.c index ae5980603bce..d8ddb90f2042 100644 --- a/fs/lustre/llite/xattr_cache.c +++ b/fs/lustre/llite/xattr_cache.c @@ -461,9 +461,9 @@ static int ll_xattr_cache_refill(struct inode *inode) CDEBUG(D_CACHE, "not caching %s\n", XATTR_NAME_ACL_ACCESS); rc = 0; - } else if (!strcmp(xdata, "security.selinux")) { - /* Filter out security.selinux, it is cached in slab */ - CDEBUG(D_CACHE, "not caching security.selinux\n"); + } else if (ll_xattr_is_seclabel(xdata)) { + /* Filter out security label, it is cached in slab */ + CDEBUG(D_CACHE, "not caching %s\n", xdata); rc = 0; } else if (!strcmp(xdata, XATTR_NAME_SOM)) { /* Filter out trusted.som, it is not cached on client */ diff --git a/fs/lustre/llite/xattr_security.c b/fs/lustre/llite/xattr_security.c index 39229d3d0f9e..9910ac6c77fc 100644 --- a/fs/lustre/llite/xattr_security.c +++ b/fs/lustre/llite/xattr_security.c @@ -38,19 +38,17 @@ /* * Check for LL_SBI_FILE_SECCTX before calling. */ -int ll_dentry_init_security(struct inode *parent, struct dentry *dentry, - int mode, struct qstr *name, - const char **secctx_name, void **secctx, - u32 *secctx_size) +int ll_dentry_init_security(struct dentry *dentry, int mode, struct qstr *name, + const char **secctx_name, u32 *secctx_name_size, + void **secctx, u32 *secctx_size) { + struct ll_sb_info *sbi = ll_s2sbi(dentry->d_sb); int rc; /* - * security_dentry_init_security() is strange. Like - * security_inode_init_security() it may return a context (provided a - * Linux security module is enabled) but unlike - * security_inode_init_security() it does not return to us the name of - * the extended attribute to store the context under (for example + * Before kernel 5.15-rc1-20-g15bf32398ad4, + * security_inode_init_security() does not return to us the name of the + * extended attribute to store the context under (for example * "security.selinux"). So we only call it when we think we know what * the name of the extended attribute will be. This is OK-ish since * SELinux is the only module that implements @@ -59,30 +57,19 @@ int ll_dentry_init_security(struct inode *parent, struct dentry *dentry, * from SELinux. */ - /* fetch length of security xattr name */ - rc = security_inode_listsecurity(parent, NULL, 0); - /* xattr name length == 0 means SELinux is disabled */ - if (rc == 0) + *secctx_name_size = ll_secctx_name_get(sbi, secctx_name); + /* xattr name length == 0 means no LSM module manage file contexts */ + if (*secctx_name_size == 0) return 0; - /* we support SELinux only */ - if (rc != strlen(XATTR_NAME_SELINUX) + 1) - return -EOPNOTSUPP; rc = security_dentry_init_security(dentry, mode, name, secctx, secctx_size); - /* Usually, security_dentry_init_security() returns -EOPNOTSUPP when - * SELinux is disabled. - * But on some kernels (e.g. rhel 8.5) it returns 0 when SELinux is - * disabled, and in this case the security context is empty. - */ - if (rc == -EOPNOTSUPP || (rc == 0 && *secctx_size == 0)) - /* do nothing */ + /* ignore error if the hook is not supported by the LSM module */ + if (rc == -EOPNOTSUPP) return 0; if (rc < 0) return rc; - *secctx_name = XATTR_NAME_SELINUX; - return 0; } @@ -139,31 +126,159 @@ int ll_inode_init_security(struct dentry *dentry, struct inode *inode, struct inode *dir) { - int err; + int rc; - err = security_inode_init_security(inode, dir, NULL, - &ll_initxattrs, dentry); + if (!ll_security_xattr_wanted(dir)) + return 0; - if (err == -EOPNOTSUPP) + rc = security_inode_init_security(inode, dir, NULL, + &ll_initxattrs, dentry); + if (rc == -EOPNOTSUPP) return 0; - return err; + + return rc; } /** - * Get security context xattr name used by policy. + * Notify security context to the security layer + * + * Notify security context @secctx of inode @inode to the security layer. * - * \retval >= 0 length of xattr name - * \retval < 0 failure to get security context xattr name + * Return 0 success, or SELinux is disabled or not supported by the fs + * < 0 failure to set the security context */ -int -ll_listsecurity(struct inode *inode, char *secctx_name, size_t secctx_name_size) +int ll_inode_notifysecctx(struct inode *inode, + void *secctx, u32 secctxlen) { + struct ll_sb_info *sbi = ll_i2sbi(inode); int rc; - rc = security_inode_listsecurity(inode, secctx_name, secctx_name_size); - if (rc >= secctx_name_size) + if (!test_bit(LL_SBI_FILE_SECCTX, sbi->ll_flags) || + !ll_security_xattr_wanted(inode) || + !secctx || !secctxlen) + return 0; + + /* no need to protect selinux_inode_setsecurity() by + * inode_lock. Taking it would lead to a client deadlock + * LU-13617 + */ + rc = security_inode_notifysecctx(inode, secctx, secctxlen); + if (rc) + CWARN("%s: cannot set security context for "DFID": rc = %d\n", + sbi->ll_fsname, PFID(ll_inode2fid(inode)), rc); + + return rc; +} + +/** + * Free the security context xattr name used by policy + */ +void ll_secctx_name_free(struct ll_sb_info *sbi) +{ + kfree(sbi->ll_secctx_name); + sbi->ll_secctx_name = NULL; + sbi->ll_secctx_name_size = 0; +} + +/** + * Get security context xattr name used by policy and save it. + * + * Return > 0 length of xattr name + * == 0 no LSM module registered supporting security contexts + * <= 0 failure to get xattr name or xattr is not supported + */ +int ll_secctx_name_store(struct inode *in) +{ + struct ll_sb_info *sbi = ll_i2sbi(in); + int rc = 0; + + if (!ll_security_xattr_wanted(in)) + return 0; + + /* get size of xattr name */ + rc = security_inode_listsecurity(in, NULL, 0); + if (rc <= 0) + return rc; + + ll_secctx_name_free(sbi); + + sbi->ll_secctx_name = kzalloc(rc + 1, GFP_NOFS); + if (!sbi->ll_secctx_name) + return -ENOMEM; + + /* save the xattr name */ + sbi->ll_secctx_name_size = rc; + rc = security_inode_listsecurity(in, sbi->ll_secctx_name, + sbi->ll_secctx_name_size); + if (rc <= 0) + goto err_free; + + if (rc > sbi->ll_secctx_name_size) { rc = -ERANGE; - else if (rc >= 0) - secctx_name[rc] = '\0'; + goto err_free; + } + + /* sanity check */ + sbi->ll_secctx_name[rc] = '\0'; + if (rc < sizeof(XATTR_SECURITY_PREFIX)) { + rc = -EINVAL; + goto err_free; + } + if (strncmp(sbi->ll_secctx_name, XATTR_SECURITY_PREFIX, + sizeof(XATTR_SECURITY_PREFIX) - 1) != 0) { + rc = -EOPNOTSUPP; + goto err_free; + } + + return rc; + +err_free: + ll_secctx_name_free(sbi); return rc; } + +/** + * Retrieved file security context xattr name stored. + * + * Return security context xattr name size stored. + * 0 no xattr name stored. + */ +u32 ll_secctx_name_get(struct ll_sb_info *sbi, const char **secctx_name) +{ + if (!sbi->ll_secctx_name || !sbi->ll_secctx_name_size) + return 0; + + *secctx_name = sbi->ll_secctx_name; + + return sbi->ll_secctx_name_size; +} + +/** + * Filter out xattr file security context if not managed by LSM + * + * This is done to improve performance for application that blindly try to get + * file context (like "ls -l" for security.linux). + * See LU-549 for more information. + * + * Return 0 xattr not filtered + * -EOPNOTSUPP no enabled LSM security module supports the xattr + */ +int ll_security_secctx_name_filter(struct ll_sb_info *sbi, int xattr_type, + const char *suffix) +{ + const char *cached_suffix = NULL; + + if (xattr_type != XATTR_SECURITY_T || + !ll_xattr_suffix_is_seclabel(suffix)) + return 0; + + /* is the xattr label used by lsm ? */ + if (!ll_secctx_name_get(sbi, &cached_suffix)) + return -EOPNOTSUPP; + + cached_suffix += sizeof(XATTR_SECURITY_PREFIX) - 1; + if (strcmp(suffix, cached_suffix) != 0) + return -EOPNOTSUPP; + + return 0; +} diff --git a/fs/lustre/ptlrpc/sec.c b/fs/lustre/ptlrpc/sec.c index 976df0bca8a8..7cd09ebe78db 100644 --- a/fs/lustre/ptlrpc/sec.c +++ b/fs/lustre/ptlrpc/sec.c @@ -1767,19 +1767,17 @@ static inline int sptlrpc_sepol_needs_check(struct ptlrpc_sec *imp_sec) int sptlrpc_get_sepol(struct ptlrpc_request *req) { -#ifndef CONFIG_SECURITY_SELINUX + struct ptlrpc_sec *imp_sec = req->rq_import->imp_sec; + int rc = 0; + (req->rq_sepol)[0] = '\0'; +#ifndef CONFIG_SECURITY_SELINUX if (unlikely(send_sepol != 0)) CDEBUG(D_SEC, "Client cannot report SELinux status, it was not built against libselinux.\n"); return 0; -#else - struct ptlrpc_sec *imp_sec = req->rq_import->imp_sec; - int rc = 0; - - (req->rq_sepol)[0] = '\0'; - +#endif if (send_sepol == 0) return 0; @@ -1794,10 +1792,13 @@ int sptlrpc_get_sepol(struct ptlrpc_request *req) memcpy(req->rq_sepol, imp_sec->ps_sepol, sizeof(req->rq_sepol)); spin_unlock(&imp_sec->ps_lock); + } else if (rc == -ENODEV) { + CDEBUG(D_SEC, + "Client cannot report SELinux status, SELinux is disabled.\n"); + rc = 0; } return rc; -#endif } EXPORT_SYMBOL(sptlrpc_get_sepol); -- 2.27.0 _______________________________________________ lustre-devel mailing list lustre-devel@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-devel-lustre.org