Remove suid/sgid bits on [f]truncate()
.. to match what we do on write(). This way, people who write to files
by using [f]truncate + writable mmap have the same semantics as if they
were using the write() family of system calls.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/open.c b/fs/open.c
index ca9981c..0d515d1 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -210,6 +210,9 @@
newattrs.ia_valid |= ATTR_FILE;
}
+ /* Remove suid/sgid on truncate too */
+ newattrs.ia_valid |= should_remove_suid(dentry);
+
mutex_lock(&dentry->d_inode->i_mutex);
err = notify_change(dentry, &newattrs);
mutex_unlock(&dentry->d_inode->i_mutex);