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authorJan Kara <jack@suse.cz>2015-05-21 17:05:54 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2015-06-24 01:01:09 +0300
commitdbfae0cdcd87602737101d4417811f4323156b54 (patch)
treebe947840a5adb296619ebd75898740de16ded617 /fs
parent5fa8e0a1c6a762857ae67d1628c58b9a02362003 (diff)
downloadlinux-dbfae0cdcd87602737101d4417811f4323156b54.tar.xz
fs: Provide function telling whether file_remove_privs() will do anything
Provide function telling whether file_remove_privs() will do anything. Currently we only have should_remove_suid() and that does something slightly different. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/inode.c44
1 files changed, 32 insertions, 12 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 849210c155dc..8c2dd74455c9 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1673,7 +1673,32 @@ int should_remove_suid(struct dentry *dentry)
}
EXPORT_SYMBOL(should_remove_suid);
-static int __remove_suid(struct dentry *dentry, int kill)
+/*
+ * Return mask of changes for notify_change() that need to be done as a
+ * response to write or truncate. Return 0 if nothing has to be changed.
+ * Negative value on error (change should be denied).
+ */
+int file_needs_remove_privs(struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = d_inode(dentry);
+ int mask = 0;
+ int ret;
+
+ if (IS_NOSEC(inode))
+ return 0;
+
+ mask = should_remove_suid(dentry);
+ ret = security_inode_need_killpriv(dentry);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ mask |= ATTR_KILL_PRIV;
+ return mask;
+}
+EXPORT_SYMBOL(file_needs_remove_privs);
+
+static int __remove_privs(struct dentry *dentry, int kill)
{
struct iattr newattrs;
@@ -1693,23 +1718,18 @@ int file_remove_privs(struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
- int killsuid;
- int killpriv;
+ int kill;
int error = 0;
/* Fast path for nothing security related */
if (IS_NOSEC(inode))
return 0;
- killsuid = should_remove_suid(dentry);
- killpriv = security_inode_need_killpriv(dentry);
-
- if (killpriv < 0)
- return killpriv;
- if (killpriv)
- error = security_inode_killpriv(dentry);
- if (!error && killsuid)
- error = __remove_suid(dentry, killsuid);
+ kill = file_needs_remove_privs(file);
+ if (kill < 0)
+ return kill;
+ if (kill)
+ error = __remove_privs(dentry, kill);
if (!error)
inode_has_no_xattr(inode);