ext{3,4}: Fix potential race when setversion ioctl updates inode
The EXT{3,4}_IOC_SETVERSION ioctl() updates i_ctime and i_generation
without i_mutex. This can lead to a race with the other operations that
update i_ctime. This is not a big issue but let's make the ioctl consistent
with how we handle e.g. other timestamp updates and use i_mutex to protect
inode changes.
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c
index ba1b54e..e7b2ed9 100644
--- a/fs/ext3/ioctl.c
+++ b/fs/ext3/ioctl.c
@@ -134,10 +134,11 @@
goto setversion_out;
}
+ mutex_lock(&inode->i_mutex);
handle = ext3_journal_start(inode, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
- goto setversion_out;
+ goto unlock_out;
}
err = ext3_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
@@ -146,6 +147,9 @@
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
}
ext3_journal_stop(handle);
+
+unlock_out:
+ mutex_unlock(&inode->i_mutex);
setversion_out:
mnt_drop_write(filp->f_path.mnt);
return err;
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a567968..46a8de6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -158,10 +158,11 @@
goto setversion_out;
}
+ mutex_lock(&inode->i_mutex);
handle = ext4_journal_start(inode, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
- goto setversion_out;
+ goto unlock_out;
}
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
@@ -170,6 +171,9 @@
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
}
ext4_journal_stop(handle);
+
+unlock_out:
+ mutex_unlock(&inode->i_mutex);
setversion_out:
mnt_drop_write(filp->f_path.mnt);
return err;
