From 25e462d9e34f8bb0cdaab78093c61373048d13a3 Mon Sep 17 00:00:00 2001 From: Ani Sinha Date: Fri, 30 Oct 2015 16:54:31 -0700 Subject: [PATCH] ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context. [ Upstream commit 44f49dd8b5a606870a1f21101522a0f9c4414784 ] Fixes the following kernel BUG : BUG: using __this_cpu_add() in preemptible [00000000] code: bash/2758 caller is __this_cpu_preempt_check+0x13/0x15 CPU: 0 PID: 2758 Comm: bash Tainted: P O 3.18.19 #2 ffffffff8170eaca ffff880110d1b788 ffffffff81482b2a 0000000000000000 0000000000000000 ffff880110d1b7b8 ffffffff812010ae ffff880007cab800 ffff88001a060800 ffff88013a899108 ffff880108b84240 ffff880110d1b7c8 Call Trace: [] dump_stack+0x52/0x80 [] check_preemption_disabled+0xce/0xe1 [] __this_cpu_preempt_check+0x13/0x15 [] ipmr_queue_xmit+0x647/0x70c [] ip_mr_forward+0x32f/0x34e [] ip_mroute_setsockopt+0xe03/0x108c [] ? get_parent_ip+0x11/0x42 [] ? pollwake+0x4d/0x51 [] ? default_wake_function+0x0/0xf [] ? get_parent_ip+0x11/0x42 [] ? __wake_up_common+0x45/0x77 [] ? _raw_spin_unlock_irqrestore+0x1d/0x32 [] ? __wake_up_sync_key+0x4a/0x53 [] ? sock_def_readable+0x71/0x75 [] do_ip_setsockopt+0x9d/0xb55 [] ? unix_seqpacket_sendmsg+0x3f/0x41 [] ? sock_sendmsg+0x6d/0x86 [] ? sockfd_lookup_light+0x12/0x5d [] ? SyS_sendto+0xf3/0x11b [] ? new_sync_read+0x82/0xaa [] compat_ip_setsockopt+0x3b/0x99 [] compat_raw_setsockopt+0x11/0x32 [] compat_sock_common_setsockopt+0x18/0x1f [] compat_SyS_setsockopt+0x1a9/0x1cf [] compat_SyS_socketcall+0x180/0x1e3 [] cstar_dispatch+0x7/0x1e Signed-off-by: Ani Sinha Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ipmr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 56d079b63ad3..6f5f943ff395 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1672,8 +1672,8 @@ static inline int ipmr_forward_finish(struct sk_buff *skb) { struct ip_options *opt = &(IPCB(skb)->opt); - IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS); - IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len); + IP_INC_STATS(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS); + IP_ADD_STATS(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len); if (unlikely(opt->optlen)) ip_forward_options(skb); @@ -1735,7 +1735,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, * to blackhole. */ - IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS); + IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); ip_rt_put(rt); goto out_free; } -- 2.20.1