linux-kernel - [PATCH] cachefiles: Handle readpage error correctly

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <160370353064.1014444.12358832243259407276.stgit@warthog.procyon.org.uk>
Date:   Mon, 26 Oct 2020 09:12:10 +0000
From:   David Howells <dhowells@...hat.com>
To:     torvalds@...ux-foundation.org
Cc:     stable@...r.kernel.org,
        "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        dhowells@...hat.com, linux-cachefs@...hat.com,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] cachefiles: Handle readpage error correctly

From: Matthew Wilcox (Oracle) <willy@...radead.org>

If ->readpage returns an error, it has already unlocked the page.

Fixes: 5e929b33c393 ("CacheFiles: Handle truncate unlocking the page we're reading")
Cc: stable@...r.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/cachefiles/rdwr.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 5b4cee71fa32..e027c718ca01 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -121,7 +121,7 @@ static int cachefiles_read_reissue(struct cachefiles_object *object,
 		_debug("reissue read");
 		ret = bmapping->a_ops->readpage(NULL, backpage);
 		if (ret < 0)
-			goto unlock_discard;
+			goto discard;
 	}
 
 	/* but the page may have been read before the monitor was installed, so
@@ -138,6 +138,7 @@ static int cachefiles_read_reissue(struct cachefiles_object *object,
 
 unlock_discard:
 	unlock_page(backpage);
+discard:
 	spin_lock_irq(&object->work_lock);
 	list_del(&monitor->op_link);
 	spin_unlock_irq(&object->work_lock);