| Message ID | 1362052783-21300-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/net/core/datagram.c b/net/core/datagram.c index ae6acf6..064151a 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -187,7 +187,7 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, skb_queue_walk(queue, skb) { *peeked = skb->peeked; if (flags & MSG_PEEK) { - if (*off >= skb->len) { + if (*off >= skb->len && skb->len) { *off -= skb->len; continue; }
This is a note to let you know that I have just added a patch titled net: fix infinite loop in __skb_recv_datagram() to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 260163e6c1697d93887a19c357e5a92756a4e784 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@google.com> Date: Tue, 12 Feb 2013 06:16:53 +0000 Subject: [PATCH] net: fix infinite loop in __skb_recv_datagram() commit 77c1090f94d1b0b5186fb13a1b71b47b1343f87f upstream. Tommi was fuzzing with trinity and reported the following problem : commit 3f518bf745 (datagram: Add offset argument to __skb_recv_datagram) missed that a raw socket receive queue can contain skbs with no payload. We can loop in __skb_recv_datagram() with MSG_PEEK mode, because wait_for_packet() is not prepared to skip these skbs. [ 83.541011] INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 0, t=26002 jiffies, g=27673, c=27672, q=75) [ 83.541011] INFO: Stall ended before state dump start [ 108.067010] BUG: soft lockup - CPU#0 stuck for 22s! [trinity-child31:2847] ... [ 108.067010] Call Trace: [ 108.067010] [<ffffffff818cc103>] __skb_recv_datagram+0x1a3/0x3b0 [ 108.067010] [<ffffffff818cc33d>] skb_recv_datagram+0x2d/0x30 [ 108.067010] [<ffffffff819ed43d>] rawv6_recvmsg+0xad/0x240 [ 108.067010] [<ffffffff818c4b04>] sock_common_recvmsg+0x34/0x50 [ 108.067010] [<ffffffff818bc8ec>] sock_recvmsg+0xbc/0xf0 [ 108.067010] [<ffffffff818bf31e>] sys_recvfrom+0xde/0x150 [ 108.067010] [<ffffffff81ca4329>] system_call_fastpath+0x16/0x1b Reported-by: Tommi Rantala <tt.rantala@gmail.com> Tested-by: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- net/core/datagram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.8.1.2