linux-kernel - [ 20/46] svcrpc: fix BUG() in svc_tcp_clear

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: <20120912233819.777174328@linuxfoundation.org>
Date:	Wed, 12 Sep 2012 16:39:10 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg KH <gregkh@...uxfoundation.org>,
	"J. Bruce Fields" <bfields@...hat.com>
Subject: [ 20/46] svcrpc: fix BUG() in svc_tcp_clear_pages

From: Greg KH <gregkh@...uxfoundation.org>

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

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

From: "J. Bruce Fields" <bfields@...hat.com>

commit be1e44441a560c43c136a562d49a1c9623c91197 upstream.

Examination of svc_tcp_clear_pages shows that it assumes sk_tcplen is
consistent with sk_pages[] (in particular, sk_pages[n] can't be NULL if
sk_tcplen would lead us to expect n pages of data).

svc_tcp_restore_pages zeroes out sk_pages[] while leaving sk_tcplen.
This is OK, since both functions are serialized by XPT_BUSY.  However,
that means the inconsistency must be repaired before dropping XPT_BUSY.

Therefore we should be ensuring that svc_tcp_save_pages repairs the
problem before exiting svc_tcp_recv_record on error.

Symptoms were a BUG() in svc_tcp_clear_pages.

Signed-off-by: J. Bruce Fields <bfields@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 net/sunrpc/svcsock.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1122,9 +1122,9 @@ static int svc_tcp_recvfrom(struct svc_r
 	if (len >= 0)
 		svsk->sk_tcplen += len;
 	if (len != want) {
+		svc_tcp_save_pages(svsk, rqstp);
 		if (len < 0 && len != -EAGAIN)
 			goto err_other;
-		svc_tcp_save_pages(svsk, rqstp);
 		dprintk("svc: incomplete TCP record (%d of %d)\n",
 			svsk->sk_tcplen, svsk->sk_reclen);
 		goto err_noclose;

--
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/