linux/net/dccp
Eric Dumazet cfac7f836a tcp/dccp: block bh before arming time_wait timer
Maciej Żenczykowski reported some panics in tcp_twsk_destructor()
that might be caused by the following bug.

timewait timer is pinned to the cpu, because we want to transition
timwewait refcount from 0 to 4 in one go, once everything has been
initialized.

At the time commit ed2e923945 ("tcp/dccp: fix timewait races in timer
handling") was merged, TCP was always running from BH habdler.

After commit 5413d1babe ("net: do not block BH while processing
socket backlog") we definitely can run tcp_time_wait() from process
context.

We need to block BH in the critical section so that the pinned timer
has still its purpose.

This bug is more likely to happen under stress and when very small RTO
are used in datacenter flows.

Fixes: 5413d1babe ("net: do not block BH while processing socket backlog")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-01 15:07:43 -05:00
..
ccids Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
Kconfig
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ackvec.c
ackvec.h
ccid.c
ccid.h
dccp.h
diag.c
feat.c dccp: fix a memleak for dccp_feat_init err process 2017-07-27 00:01:05 -07:00
feat.h
input.c net: dccp: mark expected switch fall-throughs 2017-10-16 21:15:21 +01:00
ipv4.c tcp/dccp: fix other lockdep splats accessing ireq_opt 2017-10-26 17:41:32 +09:00
ipv6.c net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv() 2017-08-31 11:43:47 -07:00
ipv6.h
minisocks.c tcp/dccp: block bh before arming time_wait timer 2017-12-01 15:07:43 -05:00
options.c net: dccp: mark expected switch fall-throughs 2017-10-16 21:15:21 +01:00
output.c
probe.c
proto.c dccp: defer ccid_hc_tx_delete() at dismantle time 2017-08-16 14:26:26 -07:00
qpolicy.c
sysctl.c
timer.c net: dccp: Convert timers to use timer_setup() 2017-10-25 12:59:19 +09:00