[JFFS2] Fix race in setting file attributes

It seems like there is a potential race in the function jffs2_do_setattr()
in the case when attributes of a symlink are updated. The symlink metadata
is read without having f->sem locked.

The following patch should fix the race.

Signed-off-by: Dmitry Bazhenov <atrey@emcraft.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
Dmitry Bazhenov 2006-05-05 22:46:49 +01:00 committed by David Woodhouse
parent edc4ff7c08
commit 422138dd68

View File

@ -56,15 +56,20 @@ static int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
mdatalen = sizeof(dev);
D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of kdev_t\n", mdatalen));
} else if (S_ISLNK(inode->i_mode)) {
down(&f->sem);
mdatalen = f->metadata->size;
mdata = kmalloc(f->metadata->size, GFP_USER);
if (!mdata)
if (!mdata) {
up(&f->sem);
return -ENOMEM;
}
ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
if (ret) {
up(&f->sem);
kfree(mdata);
return ret;
}
up(&f->sem);
D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of symlink target\n", mdatalen));
}