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| author | Serge E. Hallyn <serge@hallyn.com> | 2011-03-23 16:43:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-23 19:47:08 -0700 |
| commit | e795b71799ff0b27365020c9ddaa25d0d83f99c8 (patch) | |
| tree | f3b628c2366f181380a8fbcd490910eb086a7b8e /fs/namei.c | |
| parent | b0e77598f87107001a00b8a4ece9c95e4254ccc4 (diff) | |
| download | linux-e795b71799ff0b27365020c9ddaa25d0d83f99c8.tar.bz2 | |
userns: userns: check user namespace for task->file uid equivalence checks
Cheat for now and say all files belong to init_user_ns. Next step will be
to let superblocks belong to a user_ns, and derive inode_userns(inode)
from inode->i_sb->s_user_ns. Finally we'll introduce more flexible
arrangements.
Changelog:
Feb 15: make is_owner_or_cap take const struct inode
Feb 23: make is_owner_or_cap bool
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 21 |
1 files changed, 16 insertions, 5 deletions
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) |