diff options
| -rw-r--r-- | fs/posix_acl.c | 52 | ||||
| -rw-r--r-- | fs/xattr.c | 3 | ||||
| -rw-r--r-- | include/linux/posix_acl_xattr.h | 9 | ||||
| -rw-r--r-- | security/integrity/evm/evm_main.c | 17 |
4 files changed, 25 insertions, 56 deletions
diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 31eac28e6582..c759b8eef62e 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -771,46 +771,6 @@ void posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns, } } -void posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns, - const struct inode *inode, - void *value, size_t size) -{ - struct posix_acl_xattr_header *header = value; - struct posix_acl_xattr_entry *entry = (void *)(header + 1), *end; - struct user_namespace *fs_userns = i_user_ns(inode); - int count; - vfsuid_t vfsuid; - vfsgid_t vfsgid; - kuid_t uid; - kgid_t gid; - - if (no_idmapping(mnt_userns, i_user_ns(inode))) - return; - - count = posix_acl_fix_xattr_common(value, size); - if (count <= 0) - return; - - for (end = entry + count; entry != end; entry++) { - switch (le16_to_cpu(entry->e_tag)) { - case ACL_USER: - uid = make_kuid(&init_user_ns, le32_to_cpu(entry->e_id)); - vfsuid = VFSUIDT_INIT(uid); - uid = from_vfsuid(mnt_userns, fs_userns, vfsuid); - entry->e_id = cpu_to_le32(from_kuid(&init_user_ns, uid)); - break; - case ACL_GROUP: - gid = make_kgid(&init_user_ns, le32_to_cpu(entry->e_id)); - vfsgid = VFSGIDT_INIT(gid); - gid = from_vfsgid(mnt_userns, fs_userns, vfsgid); - entry->e_id = cpu_to_le32(from_kgid(&init_user_ns, gid)); - break; - default: - break; - } - } -} - static void posix_acl_fix_xattr_userns( struct user_namespace *to, struct user_namespace *from, void *value, size_t size) @@ -1211,7 +1171,17 @@ posix_acl_xattr_set(const struct xattr_handler *handler, int ret; if (value) { - acl = posix_acl_from_xattr(&init_user_ns, value, size); + /* + * By the time we end up here the {g,u}ids stored in + * ACL_{GROUP,USER} have already been mapped according to the + * caller's idmapping. The vfs_set_acl_prepare() helper will + * recover them and take idmapped mounts into account. The + * filesystem will receive the POSIX ACLs in in the correct + * format ready to be cached or written to the backing store + * taking the filesystem idmapping into account. + */ + acl = vfs_set_acl_prepare(mnt_userns, i_user_ns(inode), + value, size); if (IS_ERR(acl)) return PTR_ERR(acl); } diff --git a/fs/xattr.c b/fs/xattr.c index a1f4998bc6be..3ac68ec0c023 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -305,9 +305,6 @@ vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, size = error; } - if (size && is_posix_acl_xattr(name)) - posix_acl_setxattr_idmapped_mnt(mnt_userns, inode, value, size); - retry_deleg: inode_lock(inode); error = __vfs_setxattr_locked(mnt_userns, dentry, name, value, size, diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h index 47eca15fd842..8163dd48c430 100644 --- a/include/linux/posix_acl_xattr.h +++ b/include/linux/posix_acl_xattr.h @@ -38,9 +38,6 @@ void posix_acl_fix_xattr_to_user(void *value, size_t size); void posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns, const struct inode *inode, void *value, size_t size); -void posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns, - const struct inode *inode, - void *value, size_t size); #else static inline void posix_acl_fix_xattr_from_user(void *value, size_t size) { @@ -54,12 +51,6 @@ posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns, size_t size) { } -static inline void -posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns, - const struct inode *inode, void *value, - size_t size) -{ -} #endif struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns, diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 2e6fb6e2ffd2..23d484e05e6f 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -457,10 +457,21 @@ static int evm_xattr_acl_change(struct user_namespace *mnt_userns, int rc; /* - * user_ns is not relevant here, ACL_USER/ACL_GROUP don't have impact - * on the inode mode (see posix_acl_equiv_mode()). + * An earlier comment here mentioned that the idmappings for + * ACL_{GROUP,USER} don't matter since EVM is only interested in the + * mode stored as part of POSIX ACLs. Nonetheless, if it must translate + * from the uapi POSIX ACL representation to the VFS internal POSIX ACL + * representation it should do so correctly. There's no guarantee that + * we won't change POSIX ACLs in a way that ACL_{GROUP,USER} matters + * for the mode at some point and it's difficult to keep track of all + * the LSM and integrity modules and what they do to POSIX ACLs. + * + * Frankly, EVM shouldn't try to interpret the uapi struct for POSIX + * ACLs it received. It requires knowledge that only the VFS is + * guaranteed to have. */ - acl = posix_acl_from_xattr(&init_user_ns, xattr_value, xattr_value_len); + acl = vfs_set_acl_prepare(mnt_userns, i_user_ns(inode), + xattr_value, xattr_value_len); if (IS_ERR_OR_NULL(acl)) return 1; |