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From: Florian Zumbiehl <florz@florz.de>
Date: Fri, 20 Apr 2007 23:58:14 +0000 (-0700)
Subject: [PPPOE]: memory leak when socket is release()d before PPPIOCGCHAN has been called ...
X-Git-Tag: v2.6.22-rc1~1128^2~92
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=202a03acf9994076055df40ae093a5c5474ad0bd
[PPPOE]: memory leak when socket is release()d before PPPIOCGCHAN has been called on it
below you find a patch that fixes a memory leak when a PPPoE socket is
release()d after it has been connect()ed, but before the PPPIOCGCHAN ioctl
ever has been called on it.
This is somewhat of a security problem, too, since PPPoE sockets can be
created by any user, so any user can easily allocate all the machine's
RAM to non-swappable address space and thus DoS the system.
Is there any specific reason for PPPoE sockets being available to any
unprivileged process, BTW? After all, you need a packet socket for the
discovery stage anyway, so it's unlikely that any unprivileged process
will ever need to create a PPPoE socket, no? Allocating all session IDs
for a known AC is a kind of DoS, too, after all - with Juniper ERXes,
this is really easy, actually, since they don't ever assign session ids
above 8000 ...
Signed-off-by: Florian Zumbiehl <florz@florz.de>
Acked-by: Michal Ostrowski <mostrows@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
diff --git a/drivers/net/pppox.c b/drivers/net/pppox.c
index 9315046..3f8115d 100644
--- a/drivers/net/pppox.c
+++ b/drivers/net/pppox.c
@@ -58,7 +58,7 @@ void pppox_unbind_sock(struct sock *sk)
{
/* Clear connection to ppp device, if attached. */
- if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE)) {
+ if (sk->sk_state & (PPPOX_BOUND | PPPOX_CONNECTED | PPPOX_ZOMBIE)) {
ppp_unregister_channel(&pppox_sk(sk)->chan);
sk->sk_state = PPPOX_DEAD;
}
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