49 lines
1.6 KiB
Diff
49 lines
1.6 KiB
Diff
From: Eric Dumazet <eric.dumazet@gmail.com>
|
|
Date: Wed, 24 Nov 2010 17:15:27 +0000 (-0800)
|
|
Subject: af_unix: limit unix_tot_inflight
|
|
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fdavem%2Fnet-2.6.git;a=commitdiff_plain;h=9915672d41273f5b77f1b3c29b391ffb7732b84b
|
|
|
|
af_unix: limit unix_tot_inflight
|
|
|
|
Vegard Nossum found a unix socket OOM was possible, posting an exploit
|
|
program.
|
|
|
|
My analysis is we can eat all LOWMEM memory before unix_gc() being
|
|
called from unix_release_sock(). Moreover, the thread blocked in
|
|
unix_gc() can consume huge amount of time to perform cleanup because of
|
|
huge working set.
|
|
|
|
One way to handle this is to have a sensible limit on unix_tot_inflight,
|
|
tested from wait_for_unix_gc() and to force a call to unix_gc() if this
|
|
limit is hit.
|
|
|
|
This solves the OOM and also reduce overall latencies, and should not
|
|
slowdown normal workloads.
|
|
|
|
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
|
|
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
|
|
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
---
|
|
|
|
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
|
|
index c8df6fd..40df93d 100644
|
|
--- a/net/unix/garbage.c
|
|
+++ b/net/unix/garbage.c
|
|
@@ -259,9 +259,16 @@ static void inc_inflight_move_tail(struct unix_sock *u)
|
|
}
|
|
|
|
static bool gc_in_progress = false;
|
|
+#define UNIX_INFLIGHT_TRIGGER_GC 16000
|
|
|
|
void wait_for_unix_gc(void)
|
|
{
|
|
+ /*
|
|
+ * If number of inflight sockets is insane,
|
|
+ * force a garbage collect right now.
|
|
+ */
|
|
+ if (unix_tot_inflight > UNIX_INFLIGHT_TRIGGER_GC && !gc_in_progress)
|
|
+ unix_gc();
|
|
wait_event(unix_gc_wait, gc_in_progress == false);
|
|
}
|
|
|