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authorJan Stancek <jstancek@redhat.com>2015-02-11 14:06:23 +0100
committerDavid S. Miller <davem@davemloft.net>2015-02-12 07:13:03 -0800
commit4762fb980465463734f02c67c67f40beb8903f73 (patch)
tree166aafe2a2132c02a152ea756ed4216bad447eac /net
parent6aa6395ff320abe242e05766ae201f23e7978a94 (diff)
downloadlinux-4762fb980465463734f02c67c67f40beb8903f73.tar.bz2
ipv6: fix possible deadlock in ip6_fl_purge / ip6_fl_gc
Use spin_lock_bh in ip6_fl_purge() to prevent following potentially deadlock scenario between ip6_fl_purge() and ip6_fl_gc() timer. ================================= [ INFO: inconsistent lock state ] 3.19.0 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/5/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ip6_fl_lock){+.?...}, at: [<ffffffff8171155d>] ip6_fl_gc+0x2d/0x180 {SOFTIRQ-ON-W} state was registered at: [<ffffffff810ee9a0>] __lock_acquire+0x4a0/0x10b0 [<ffffffff810efd54>] lock_acquire+0xc4/0x2b0 [<ffffffff81751d2d>] _raw_spin_lock+0x3d/0x80 [<ffffffff81711798>] ip6_flowlabel_net_exit+0x28/0x110 [<ffffffff815f9759>] ops_exit_list.isra.1+0x39/0x60 [<ffffffff815fa320>] cleanup_net+0x100/0x1e0 [<ffffffff810ad80a>] process_one_work+0x20a/0x830 [<ffffffff810adf4b>] worker_thread+0x11b/0x460 [<ffffffff810b42f4>] kthread+0x104/0x120 [<ffffffff81752bfc>] ret_from_fork+0x7c/0xb0 irq event stamp: 84640 hardirqs last enabled at (84640): [<ffffffff81752080>] _raw_spin_unlock_irq+0x30/0x50 hardirqs last disabled at (84639): [<ffffffff81751eff>] _raw_spin_lock_irq+0x1f/0x80 softirqs last enabled at (84628): [<ffffffff81091ad1>] _local_bh_enable+0x21/0x50 softirqs last disabled at (84629): [<ffffffff81093b7d>] irq_exit+0x12d/0x150 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ip6_fl_lock); <Interrupt> lock(ip6_fl_lock); *** DEADLOCK *** Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/ip6_flowlabel.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 2f780cba6e12..f45d6db50a45 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -172,7 +172,7 @@ static void __net_exit ip6_fl_purge(struct net *net)
{
int i;
- spin_lock(&ip6_fl_lock);
+ spin_lock_bh(&ip6_fl_lock);
for (i = 0; i <= FL_HASH_MASK; i++) {
struct ip6_flowlabel *fl;
struct ip6_flowlabel __rcu **flp;
@@ -190,7 +190,7 @@ static void __net_exit ip6_fl_purge(struct net *net)
flp = &fl->next;
}
}
- spin_unlock(&ip6_fl_lock);
+ spin_unlock_bh(&ip6_fl_lock);
}
static struct ip6_flowlabel *fl_intern(struct net *net,