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authorEric Paris <eparis@redhat.com>2010-07-23 11:43:51 -0400
committerJames Morris <jmorris@namei.org>2010-08-02 15:35:06 +1000
commit9cfcac810e8993fa7a5bfd24b1a21f1dbbb03a7b (patch)
tree86fae80c744e46b15b8eb9aa23fead7e63a64159
parentSELinux: break ocontext reading into a separate function (diff)
downloadlinux-dev-9cfcac810e8993fa7a5bfd24b1a21f1dbbb03a7b.tar.xz
linux-dev-9cfcac810e8993fa7a5bfd24b1a21f1dbbb03a7b.zip
vfs: re-introduce MAY_CHDIR
Currently MAY_ACCESS means that filesystems must check the permissions right then and not rely on cached results or the results of future operations on the object. This can be because of a call to sys_access() or because of a call to chdir() which needs to check search without relying on any future operations inside that dir. I plan to use MAY_ACCESS for other purposes in the security system, so I split the MAY_ACCESS and the MAY_CHDIR cases. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
-rw-r--r--fs/fuse/dir.c2
-rw-r--r--fs/nfs/dir.c2
-rw-r--r--fs/open.c6
-rw-r--r--include/linux/fs.h1
4 files changed, 6 insertions, 5 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 3cdc5f78a406..431be0795b6b 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1016,7 +1016,7 @@ static int fuse_permission(struct inode *inode, int mask)
exist. So if permissions are revoked this won't be
noticed immediately, only after the attribute
timeout has expired */
- } else if (mask & MAY_ACCESS) {
+ } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
err = fuse_access(inode, mask);
} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
if (!(inode->i_mode & S_IXUGO)) {
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index e60416d3f818..832e9e239324 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1953,7 +1953,7 @@ int nfs_permission(struct inode *inode, int mask)
if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
goto out;
/* Is this sys_access() ? */
- if (mask & MAY_ACCESS)
+ if (mask & (MAY_ACCESS | MAY_CHDIR))
goto force_lookup;
switch (inode->i_mode & S_IFMT) {
diff --git a/fs/open.c b/fs/open.c
index a54ed85209c1..0d1fa3dc0efb 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -366,7 +366,7 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
if (error)
goto out;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
+ error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
@@ -395,7 +395,7 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd)
if (!S_ISDIR(inode->i_mode))
goto out_putf;
- error = inode_permission(inode, MAY_EXEC | MAY_ACCESS);
+ error = inode_permission(inode, MAY_EXEC | MAY_CHDIR);
if (!error)
set_fs_pwd(current->fs, &file->f_path);
out_putf:
@@ -413,7 +413,7 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
if (error)
goto out;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
+ error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 68ca1b0491af..7d94b72f0346 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -53,6 +53,7 @@ struct inodes_stat_t {
#define MAY_APPEND 8
#define MAY_ACCESS 16
#define MAY_OPEN 32
+#define MAY_CHDIR 64
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond