linux-kernel - [ 202/221] libceph: avoid using freed osd in __kick_osd

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

Message-Id: <20130115185012.619348963@linuxfoundation.org>
Date:	Tue, 15 Jan 2013 10:52:09 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	alan@...rguk.ukuu.org.uk, Alex Elder <elder@...tank.com>,
	Sage Weil <sage@...tank.com>
Subject: [ 202/221] libceph: avoid using freed osd in __kick_osd_requests()

3.7-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Alex Elder <elder@...tank.com>

(cherry picked from commit 685a7555ca69030739ddb57a47f0ea8ea80196a4)

If an osd has no requests and no linger requests, __reset_osd()
will just remove it with a call to __remove_osd().  That drops
a reference to the osd, and therefore the osd may have been free
by the time __reset_osd() returns.  That function offers no
indication this may have occurred, and as a result the osd will
continue to be used even when it's no longer valid.

Change__reset_osd() so it returns an error (ENODEV) when it
deletes the osd being reset.  And change __kick_osd_requests() so it
returns immediately (before referencing osd again) if __reset_osd()
returns *any* error.

Signed-off-by: Alex Elder <elder@...tank.com>
Reviewed-by: Sage Weil <sage@...tank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/ceph/osd_client.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -581,7 +581,7 @@ static void __kick_osd_requests(struct c
 
 	dout("__kick_osd_requests osd%d\n", osd->o_osd);
 	err = __reset_osd(osdc, osd);
-	if (err == -EAGAIN)
+	if (err)
 		return;
 
 	list_for_each_entry(req, &osd->o_requests, r_osd_item) {
@@ -752,6 +752,7 @@ static int __reset_osd(struct ceph_osd_c
 	if (list_empty(&osd->o_requests) &&
 	    list_empty(&osd->o_linger_requests)) {
 		__remove_osd(osdc, osd);
+		ret = -ENODEV;
 	} else if (memcmp(&osdc->osdmap->osd_addr[osd->o_osd],
 			  &osd->o_con.peer_addr,
 			  sizeof(osd->o_con.peer_addr)) == 0 &&


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/