diff options
| -rw-r--r-- | fs/inode.c | 17 | ||||
| -rw-r--r-- | fs/namei.c | 21 | ||||
| -rw-r--r-- | include/linux/fs.h | 9 |
3 files changed, 40 insertions, 7 deletions
diff --git a/fs/inode.c b/fs/inode.c index 16fefd373fc2..a21d5a938a17 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -25,6 +25,7 @@ #include <linux/async.h> #include <linux/posix_acl.h> #include <linux/ima.h> +#include <linux/cred.h> /* * This is needed for the following functions: @@ -1733,3 +1734,19 @@ void inode_init_owner(struct inode *inode, const struct inode *dir, inode->i_mode = mode; } EXPORT_SYMBOL(inode_init_owner); + +/* + * return true if current either has CAP_FOWNER to the + * file, or owns the file. + */ +bool is_owner_or_cap(const struct inode *inode) +{ + struct user_namespace *ns = inode_userns(inode); + + if (current_user_ns() == ns && current_fsuid() == inode->i_uid) + return true; + if (ns_capable(ns, CAP_FOWNER)) + return true; + return false; +} +EXPORT_SYMBOL(is_owner_or_cap); diff --git a/fs/namei.c b/fs/namei.c index 5a9a6c3094da..dbb45a652ae3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -183,6 +183,9 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag mask &= MAY_READ | MAY_WRITE | MAY_EXEC; + if (current_user_ns() != inode_userns(inode)) + goto other_perms; + if (current_fsuid() == inode->i_uid) mode >>= 6; else { @@ -196,6 +199,7 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag mode >>= 3; } +other_perms: /* * If the DACs are ok we don't need any capability check. */ @@ -237,7 +241,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags, * Executable DACs are overridable if at least one exec bit is set. */ if (!(mask & MAY_EXEC) || execute_ok(inode)) - if (capable(CAP_DAC_OVERRIDE)) + if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE)) return 0; /* @@ -245,7 +249,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags, */ mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE))) - if (capable(CAP_DAC_READ_SEARCH)) + if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH)) return 0; return -EACCES; @@ -654,6 +658,7 @@ static inline int handle_reval_path(struct nameidata *nd) static inline int exec_permission(struct inode *inode, unsigned int flags) { int ret; + struct user_namespace *ns = inode_userns(inode); if (inode->i_op->permission) { ret = inode->i_op->permission(inode, MAY_EXEC, flags); @@ -666,7 +671,8 @@ static inline int exec_permission(struct inode *inode, unsigned int flags) if (ret == -ECHILD) return ret; - if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH)) + if (ns_capable(ns, CAP_DAC_OVERRIDE) || + ns_capable(ns, CAP_DAC_READ_SEARCH)) goto ok; return ret; @@ -1842,11 +1848,15 @@ static inline int check_sticky(struct inode *dir, struct inode *inode) if (!(dir->i_mode & S_ISVTX)) return 0; + if (current_user_ns() != inode_userns(inode)) + goto other_userns; if (inode->i_uid == fsuid) return 0; if (dir->i_uid == fsuid) return 0; - return !capable(CAP_FOWNER); + +other_userns: + return !ns_capable(inode_userns(inode), CAP_FOWNER); } /* @@ -2440,7 +2450,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) if (error) return error; - if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) + if ((S_ISCHR(mode) || S_ISBLK(mode)) && + !ns_capable(inode_userns(dir), CAP_MKNOD)) return -EPERM; if (!dir->i_op->mknod) diff --git a/include/linux/fs.h b/include/linux/fs.h index 12529e966350..9eebc646d14a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1457,8 +1457,13 @@ enum { #define put_fs_excl() atomic_dec(¤t->fs_excl) #define has_fs_excl() atomic_read(¤t->fs_excl) -#define is_owner_or_cap(inode) \ - ((current_fsuid() == (inode)->i_uid) || capable(CAP_FOWNER)) +/* + * until VFS tracks user namespaces for inodes, just make all files + * belong to init_user_ns + */ +extern struct user_namespace init_user_ns; +#define inode_userns(inode) (&init_user_ns) +extern bool is_owner_or_cap(const struct inode *inode); /* not quite ready to be deprecated, but... */ extern void lock_super(struct super_block *); |