afs: Fix page leak in afs_write_begin()

[ Upstream commit 6d06b0d25209c80e99c1e89700f1e09694a3766b ]

afs_write_begin() leaks a ref and a lock on a page if afs_fill_page()
fails.  Fix the leak by unlocking and releasing the page in the error path.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Howells 2017-03-16 16:27:48 +00:00 committed by Greg Kroah-Hartman
parent c58d7796ab
commit 80f74cef48

View File

@ -148,12 +148,12 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
kfree(candidate);
return -ENOMEM;
}
*pagep = page;
/* page won't leak in error case: it eventually gets cleaned off LRU */
if (!PageUptodate(page) && len != PAGE_CACHE_SIZE) {
ret = afs_fill_page(vnode, key, index << PAGE_CACHE_SHIFT, page);
if (ret < 0) {
unlock_page(page);
put_page(page);
kfree(candidate);
_leave(" = %d [prep]", ret);
return ret;
@ -161,6 +161,9 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
SetPageUptodate(page);
}
/* page won't leak in error case: it eventually gets cleaned off LRU */
*pagep = page;
try_again:
spin_lock(&vnode->writeback_lock);