netdev - [PATCH net 1/5] ppp: lock ppp structure before modifying mru in ppp

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]

Date:	Mon, 22 Feb 2016 20:47:13 +0100
From:	Guillaume Nault <g.nault@...halink.fr>
To:	netdev@...r.kernel.org
Cc:	Paul Mackerras <paulus@...ba.org>,
	David Miller <davem@...emloft.net>
Subject: [PATCH net 1/5] ppp: lock ppp structure before modifying mru in
 ppp_ioctl()

PPP's Tx and Rx paths read ppp->mru under protection of ppp_xmit_lock()
and ppp_recv_lock() respectively.
Therefore ppp_ioctl() must hold the xmit and recv locks before
concurrently updating ppp->mru.

Signed-off-by: Guillaume Nault <g.nault@...halink.fr>
---
 drivers/net/ppp/ppp_generic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index fc8ad00..4d342ae 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -654,7 +654,10 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case PPPIOCSMRU:
 		if (get_user(val, p))
 			break;
+		ppp_lock(ppp);
 		ppp->mru = val;
+		ppp_unlock(ppp);
+
 		err = 0;
 		break;
 
-- 
2.7.0