From 5d6c31910bc0713e37628dc0ce677dcb13c8ccf4 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 29 Sep 2016 17:48:42 +0200 Subject: [PATCH] xattr: Add __vfs_{get,set,remove}xattr helpers Right now, various places in the kernel check for the existence of getxattr, setxattr, and removexattr inode operations and directly call those operations. Switch to helper functions and test for the IOP_XATTR flag instead. Signed-off-by: Andreas Gruenbacher Acked-by: James Morris Signed-off-by: Al Viro --- fs/cachefiles/bind.c | 4 +-- fs/cachefiles/namei.c | 4 +-- fs/ecryptfs/inode.c | 18 +++++------ fs/ecryptfs/mmap.c | 13 ++++---- fs/overlayfs/copy_up.c | 4 +-- fs/overlayfs/super.c | 4 +-- fs/xattr.c | 46 ++++++++++++++++++++------- include/linux/xattr.h | 3 ++ security/commoncap.c | 25 ++++++--------- security/integrity/evm/evm_crypto.c | 7 ++-- security/integrity/evm/evm_main.c | 4 +-- security/integrity/ima/ima_appraise.c | 21 ++++++------ security/selinux/hooks.c | 19 ++++------- security/smack/smack_lsm.c | 12 +++---- 14 files changed, 98 insertions(+), 86 deletions(-) diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c index 6af790fc3df8..3ff867f87d73 100644 --- a/fs/cachefiles/bind.c +++ b/fs/cachefiles/bind.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "internal.h" static int cachefiles_daemon_add_cache(struct cachefiles_cache *caches); @@ -126,8 +127,7 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache) if (d_is_negative(root) || !d_backing_inode(root)->i_op->lookup || !d_backing_inode(root)->i_op->mkdir || - !d_backing_inode(root)->i_op->setxattr || - !d_backing_inode(root)->i_op->getxattr || + !(d_backing_inode(root)->i_opflags & IOP_XATTR) || !root->d_sb->s_op->statfs || !root->d_sb->s_op->sync_fs) goto error_unsupported; diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index 3f7c2cd41f8f..6eb3dec2adbb 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "internal.h" #define CACHEFILES_KEYBUF_SIZE 512 @@ -799,8 +800,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, } ret = -EPERM; - if (!d_backing_inode(subdir)->i_op->setxattr || - !d_backing_inode(subdir)->i_op->getxattr || + if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || !d_backing_inode(subdir)->i_op->lookup || !d_backing_inode(subdir)->i_op->mkdir || !d_backing_inode(subdir)->i_op->create || diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index cef32ccc3fcb..32fee255d7b5 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -1005,15 +1005,14 @@ ecryptfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name, const void *value, size_t size, int flags) { - int rc = 0; + int rc; struct dentry *lower_dentry; lower_dentry = ecryptfs_dentry_to_lower(dentry); - if (!d_inode(lower_dentry)->i_op->setxattr) { + if (!(d_inode(lower_dentry)->i_opflags & IOP_XATTR)) { rc = -EOPNOTSUPP; goto out; } - rc = vfs_setxattr(lower_dentry, name, value, size, flags); if (!rc && inode) fsstack_copy_attr_all(inode, d_inode(lower_dentry)); @@ -1025,15 +1024,14 @@ ssize_t ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode, const char *name, void *value, size_t size) { - int rc = 0; + int rc; - if (!lower_inode->i_op->getxattr) { + if (!(lower_inode->i_opflags & IOP_XATTR)) { rc = -EOPNOTSUPP; goto out; } inode_lock(lower_inode); - rc = lower_inode->i_op->getxattr(lower_dentry, lower_inode, - name, value, size); + rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size); inode_unlock(lower_inode); out: return rc; @@ -1069,18 +1067,18 @@ out: static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode, const char *name) { - int rc = 0; + int rc; struct dentry *lower_dentry; struct inode *lower_inode; lower_dentry = ecryptfs_dentry_to_lower(dentry); lower_inode = ecryptfs_inode_to_lower(inode); - if (!lower_inode->i_op->removexattr) { + if (!(lower_inode->i_opflags & IOP_XATTR)) { rc = -EOPNOTSUPP; goto out; } inode_lock(lower_inode); - rc = lower_inode->i_op->removexattr(lower_dentry, name); + rc = __vfs_removexattr(lower_dentry, name); inode_unlock(lower_inode); out: return rc; diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 9c3437c8a5b1..1f0c471b4ba3 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include "ecryptfs_kernel.h" @@ -422,7 +423,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) struct inode *lower_inode = d_inode(lower_dentry); int rc; - if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { + if (!(lower_inode->i_opflags & IOP_XATTR)) { printk(KERN_WARNING "No support for setting xattr in lower filesystem\n"); rc = -ENOSYS; @@ -436,15 +437,13 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) goto out; } inode_lock(lower_inode); - size = lower_inode->i_op->getxattr(lower_dentry, lower_inode, - ECRYPTFS_XATTR_NAME, - xattr_virt, PAGE_SIZE); + size = __vfs_getxattr(lower_dentry, lower_inode, ECRYPTFS_XATTR_NAME, + xattr_virt, PAGE_SIZE); if (size < 0) size = 8; put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); - rc = lower_inode->i_op->setxattr(lower_dentry, lower_inode, - ECRYPTFS_XATTR_NAME, - xattr_virt, size, 0); + rc = __vfs_setxattr(lower_dentry, lower_inode, ECRYPTFS_XATTR_NAME, + xattr_virt, size, 0); inode_unlock(lower_inode); if (rc) printk(KERN_ERR "Error whilst attempting to write inode size " diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 43fdc2765aea..807951cb438c 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -58,8 +58,8 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) char *buf, *name, *value = NULL; int uninitialized_var(error); - if (!old->d_inode->i_op->getxattr || - !new->d_inode->i_op->getxattr) + if (!(old->d_inode->i_opflags & IOP_XATTR) || + !(new->d_inode->i_opflags & IOP_XATTR)) return 0; list_size = vfs_listxattr(old, NULL, 0); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index e2a94a26767b..f170114481f7 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -275,10 +275,10 @@ static bool ovl_is_opaquedir(struct dentry *dentry) char val; struct inode *inode = dentry->d_inode; - if (!S_ISDIR(inode->i_mode) || !inode->i_op->getxattr) + if (!S_ISDIR(inode->i_mode) || !(inode->i_opflags & IOP_XATTR)) return false; - res = inode->i_op->getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1); + res = __vfs_getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1); if (res == 1 && val == 'y') return true; diff --git a/fs/xattr.c b/fs/xattr.c index 1f5d0b48422a..54a411519127 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -136,6 +136,16 @@ xattr_permission(struct inode *inode, const char *name, int mask) return inode_permission(inode, mask); } +int +__vfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + if (!inode->i_op->setxattr) + return -EOPNOTSUPP; + return inode->i_op->setxattr(dentry, inode, name, value, size, flags); +} +EXPORT_SYMBOL(__vfs_setxattr); + /** * __vfs_setxattr_noperm - perform setxattr operation without performing * permission checks. @@ -163,7 +173,7 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, if (issec) inode->i_flags &= ~S_NOSEC; if (inode->i_op->setxattr) { - error = inode->i_op->setxattr(dentry, inode, name, value, size, flags); + error = __vfs_setxattr(dentry, inode, name, value, size, flags); if (!error) { fsnotify_xattr(dentry); security_inode_post_setxattr(dentry, name, value, @@ -274,6 +284,16 @@ vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, return error; } +ssize_t +__vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name, + void *value, size_t size) +{ + if (!inode->i_op->getxattr) + return -EOPNOTSUPP; + return inode->i_op->getxattr(dentry, inode, name, value, size); +} +EXPORT_SYMBOL(__vfs_getxattr); + ssize_t vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) { @@ -301,13 +321,7 @@ vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) return ret; } nolsm: - if (inode->i_op->getxattr) - error = inode->i_op->getxattr(dentry, inode, name, value, size); - else - error = -EOPNOTSUPP; - - return error; - + return __vfs_getxattr(dentry, inode, name, value, size); } EXPORT_SYMBOL_GPL(vfs_getxattr); @@ -331,15 +345,23 @@ vfs_listxattr(struct dentry *d, char *list, size_t size) } EXPORT_SYMBOL_GPL(vfs_listxattr); +int +__vfs_removexattr(struct dentry *dentry, const char *name) +{ + struct inode *inode = dentry->d_inode; + + if (!inode->i_op->removexattr) + return -EOPNOTSUPP; + return inode->i_op->removexattr(dentry, name); +} +EXPORT_SYMBOL(__vfs_removexattr); + int vfs_removexattr(struct dentry *dentry, const char *name) { struct inode *inode = dentry->d_inode; int error; - if (!inode->i_op->removexattr) - return -EOPNOTSUPP; - error = xattr_permission(inode, name, MAY_WRITE); if (error) return error; @@ -349,7 +371,7 @@ vfs_removexattr(struct dentry *dentry, const char *name) if (error) goto out; - error = inode->i_op->removexattr(dentry, name); + error = __vfs_removexattr(dentry, name); if (!error) { fsnotify_xattr(dentry); diff --git a/include/linux/xattr.h b/include/linux/xattr.h index 94079bab9243..6ae6b2e68efb 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -46,10 +46,13 @@ struct xattr { }; ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t); +ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); +int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int); int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); +int __vfs_removexattr(struct dentry *, const char *); int vfs_removexattr(struct dentry *, const char *); ssize_t generic_getxattr(struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size); diff --git a/security/commoncap.c b/security/commoncap.c index 14540bd78561..8df676fbd393 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -310,13 +310,8 @@ int cap_inode_need_killpriv(struct dentry *dentry) struct inode *inode = d_backing_inode(dentry); int error; - if (!inode->i_op->getxattr) - return 0; - - error = inode->i_op->getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0); - if (error <= 0) - return 0; - return 1; + error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0); + return error > 0; } /** @@ -329,12 +324,12 @@ int cap_inode_need_killpriv(struct dentry *dentry) */ int cap_inode_killpriv(struct dentry *dentry) { - struct inode *inode = d_backing_inode(dentry); + int error; - if (!inode->i_op->removexattr) - return 0; - - return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); + error = __vfs_removexattr(dentry, XATTR_NAME_CAPS); + if (error == -EOPNOTSUPP) + error = 0; + return error; } /* @@ -394,11 +389,11 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); - if (!inode || !inode->i_op->getxattr) + if (!inode) return -ENODATA; - size = inode->i_op->getxattr((struct dentry *)dentry, inode, - XATTR_NAME_CAPS, &caps, XATTR_CAPS_SZ); + size = __vfs_getxattr((struct dentry *)dentry, inode, + XATTR_NAME_CAPS, &caps, XATTR_CAPS_SZ); if (size == -ENODATA || size == -EOPNOTSUPP) /* no data, that's ok */ return -ENODATA; diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index 11c1d30bd705..bf663915412e 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -182,8 +182,9 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, int error; int size; - if (!inode->i_op->getxattr) + if (!(inode->i_opflags & IOP_XATTR)) return -EOPNOTSUPP; + desc = init_desc(type); if (IS_ERR(desc)) return PTR_ERR(desc); @@ -253,8 +254,8 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM, &xattr_data, sizeof(xattr_data), 0); - } else if (rc == -ENODATA && inode->i_op->removexattr) { - rc = inode->i_op->removexattr(dentry, XATTR_NAME_EVM); + } else if (rc == -ENODATA && (inode->i_opflags & IOP_XATTR)) { + rc = __vfs_removexattr(dentry, XATTR_NAME_EVM); } return rc; } diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index b9e26288d30c..ba8615576d4d 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -78,11 +78,11 @@ static int evm_find_protected_xattrs(struct dentry *dentry) int error; int count = 0; - if (!inode->i_op->getxattr) + if (!(inode->i_opflags & IOP_XATTR)) return -EOPNOTSUPP; for (xattr = evm_config_xattrnames; *xattr != NULL; xattr++) { - error = inode->i_op->getxattr(dentry, inode, *xattr, NULL, 0); + error = __vfs_getxattr(dentry, inode, *xattr, NULL, 0); if (error < 0) { if (error == -ENODATA) continue; diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 4b9b4a4e1b89..0cc40af9c218 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -165,13 +165,13 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value) { - struct inode *inode = d_backing_inode(dentry); + ssize_t ret; - if (!inode->i_op->getxattr) - return 0; - - return vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value, - 0, GFP_NOFS); + ret = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value, + 0, GFP_NOFS); + if (ret == -EOPNOTSUPP) + ret = 0; + return ret; } /* @@ -195,7 +195,7 @@ int ima_appraise_measurement(enum ima_hooks func, enum integrity_status status = INTEGRITY_UNKNOWN; int rc = xattr_len, hash_start = 0; - if (!inode->i_op->getxattr) + if (!(inode->i_opflags & IOP_XATTR)) return INTEGRITY_UNKNOWN; if (rc <= 0) { @@ -322,10 +322,10 @@ void ima_inode_post_setattr(struct dentry *dentry) { struct inode *inode = d_backing_inode(dentry); struct integrity_iint_cache *iint; - int must_appraise, rc; + int must_appraise; if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode) - || !inode->i_op->removexattr) + || !(inode->i_opflags & IOP_XATTR)) return; must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR); @@ -338,8 +338,7 @@ void ima_inode_post_setattr(struct dentry *dentry) iint->flags |= IMA_APPRAISE; } if (!must_appraise) - rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); - return; + __vfs_removexattr(dentry, XATTR_NAME_IMA); } /* diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 13185a6c266a..3db31ac7986b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -507,14 +507,14 @@ static int sb_finish_set_opts(struct super_block *sb) the root directory. -ENODATA is ok, as this may be the first boot of the SELinux kernel before we have assigned xattr values to the filesystem. */ - if (!root_inode->i_op->getxattr) { + if (!(root_inode->i_opflags & IOP_XATTR)) { printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " "xattr support\n", sb->s_id, sb->s_type->name); rc = -EOPNOTSUPP; goto out; } - rc = root_inode->i_op->getxattr(root, root_inode, - XATTR_NAME_SELINUX, NULL, 0); + + rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); if (rc < 0 && rc != -ENODATA) { if (rc == -EOPNOTSUPP) printk(KERN_WARNING "SELinux: (dev %s, type " @@ -1410,11 +1410,10 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent case SECURITY_FS_USE_NATIVE: break; case SECURITY_FS_USE_XATTR: - if (!inode->i_op->getxattr) { + if (!(inode->i_opflags & IOP_XATTR)) { isec->sid = sbsec->def_sid; break; } - /* Need a dentry, since the xattr API requires one. Life would be simpler if we could just pass the inode. */ if (opt_dentry) { @@ -1445,14 +1444,12 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent goto out_unlock; } context[len] = '\0'; - rc = inode->i_op->getxattr(dentry, inode, XATTR_NAME_SELINUX, - context, len); + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); if (rc == -ERANGE) { kfree(context); /* Need a larger buffer. Query for the right size. */ - rc = inode->i_op->getxattr(dentry, inode, XATTR_NAME_SELINUX, - NULL, 0); + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); if (rc < 0) { dput(dentry); goto out_unlock; @@ -1465,9 +1462,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent goto out_unlock; } context[len] = '\0'; - rc = inode->i_op->getxattr(dentry, inode, - XATTR_NAME_SELINUX, - context, len); + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); } dput(dentry); if (rc < 0) { diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 87a9741b0d02..516b3f50f23d 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -265,14 +265,14 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip, char *buffer; struct smack_known *skp = NULL; - if (ip->i_op->getxattr == NULL) + if (!(ip->i_opflags & IOP_XATTR)) return ERR_PTR(-EOPNOTSUPP); buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); if (buffer == NULL) return ERR_PTR(-ENOMEM); - rc = ip->i_op->getxattr(dp, ip, name, buffer, SMK_LONGLABEL); + rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); if (rc < 0) skp = ERR_PTR(rc); else if (rc == 0) @@ -3520,8 +3520,8 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) * It would be curious if the label of the task * does not match that assigned. */ - if (inode->i_op->getxattr == NULL) - break; + if (!(inode->i_opflags & IOP_XATTR)) + break; /* * Get the dentry for xattr. */ @@ -3545,12 +3545,12 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) */ if (isp->smk_flags & SMK_INODE_CHANGED) { isp->smk_flags &= ~SMK_INODE_CHANGED; - rc = inode->i_op->setxattr(dp, inode, + rc = __vfs_setxattr(dp, inode, XATTR_NAME_SMACKTRANSMUTE, TRANS_TRUE, TRANS_TRUE_SIZE, 0); } else { - rc = inode->i_op->getxattr(dp, inode, + rc = __vfs_getxattr(dp, inode, XATTR_NAME_SMACKTRANSMUTE, trattr, TRANS_TRUE_SIZE); if (rc >= 0 && strncmp(trattr, TRANS_TRUE,