Commit 202a03ac authored by Florian Zumbiehl's avatar Florian Zumbiehl Committed by David S. Miller

[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: default avatarFlorian Zumbiehl <>
Acked-by: default avatarMichal Ostrowski <>
Signed-off-by: default avatarDavid S. Miller <>
parent 74b885cf
......@@ -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)) {
sk->sk_state = PPPOX_DEAD;
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