| Message ID | 20120718182711.22872.95370.stgit@jf-dev1-dcblab |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: John Fastabend <john.r.fastabend@intel.com> Date: Wed, 18 Jul 2012 11:27:11 -0700 > @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); > LIST_HEAD(net_namespace_list); > EXPORT_SYMBOL_GPL(net_namespace_list); > > -struct net init_net; > +struct net init_net = { > + .count = ATOMIC_INIT(0), > + }; > EXPORT_SYMBOL(init_net); That's some fancy indentation you've got there cowboy. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index dddbacb..0d37c94 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); -struct net init_net; +struct net init_net = { + .count = ATOMIC_INIT(0), + }; EXPORT_SYMBOL(init_net); #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index b2e9caa..e9fd7fd 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -116,6 +116,9 @@ static int update_netdev_tables(void) u32 max_len; struct netprio_map *map; + if (!atomic_read(&init_net.count)) + return ret; + rtnl_lock(); max_len = atomic_read(&max_prioidx) + 1; for_each_netdev(&init_net, dev) {
When the netprio cgroup is built in the kernel cgroup_init will call cgrp_create which eventually calls update_netdev_tables. This is being called before do_initcalls() so a null ptr dereference occurs on init_net. This patch adds a check on init_net.count to verify the structure has been initialized. The failure was introduced here, commit ef209f15980360f6945873df3cd710c5f62f2a3e Author: Gao feng <gaofeng@cn.fujitsu.com> Date: Wed Jul 11 21:50:15 2012 +0000 net: cgroup: fix access the unallocated memory in netprio cgroup Tested with ping with netprio_cgroup as a module and built in. [ 0.256451] Initializing cgroup subsys net_prio [ 0.269948] BUG: unable to handle kernel NULL pointer dereference at 0000000000000698 [ 0.293303] IP: [<ffffffff81512e37>] cgrp_create+0x107/0x1c0 [ 0.310175] PGD 0 [ 0.316157] Oops: 0000 [#1] SMP [ 0.325775] CPU 0 [ 0.331227] Modules linked in: [ 0.340846] [ 0.345264] Pid: 0, comm: swapper/0 Not tainted 3.5.0-rc7+ #1 AMD Dinar/Dinar [ 0.366555] RIP: 0010:[<ffffffff81512e37>] [<ffffffff81512e37>] cgrp_create+0x107/0x1c0 [ 0.390681] RSP: 0000:ffffffff81c01ea8 EFLAGS: 00010213 [ 0.406501] RAX: 0000000000000000 RBX: ffffffffffffff10 RCX: 0000000000000000 [ 0.427764] RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffffffff81c9d840 [ 0.449026] RBP: ffffffff81c01ed8 R08: 00000000000164e0 R09: 0000000000000000 [ 0.470289] R10: ffff8804278303c0 R11: 0000000000000000 R12: 0000000000000001 [ 0.491553] R13: ffff8804278303c0 R14: ffff881036fd0700 R15: 0000000000000000 [ 0.512819] FS: 0000000000000000(0000) GS:ffff880427c00000(0000) knlGS:0000000000000000 [ 0.536932] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 0.554049] CR2: 0000000000000698 CR3: 0000000001c0b000 CR4: 00000000000406b0 [ 0.575311] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 0.596574] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 0.617838] Process swapper/0 (pid: 0, threadinfo ffffffff81c00000, task ffffffff81c13420) [ 0.642471] Stack: [ 0.648442] ffffffff81c01eb8 ffffffff81c9f320 ffffffff81c9f320 ffffffff81c9f320 [ 0.670522] ffffffff81c9f320 ffffffff81d482c0 ffffffff81c01ef8 ffffffff81d10397 [ 0.692604] ffffffff81e99790 0000000000000048 ffffffff81c01f18 ffffffff81d1062e [ 0.714687] Call Trace: [ 0.721960] [<ffffffff81d10397>] cgroup_init_subsys+0x51/0xdf [ 0.739337] [<ffffffff81d1062e>] cgroup_init+0x36/0x119 [ 0.755160] [<ffffffff81cf5c02>] start_kernel+0x38f/0x3c4 [ 0.771501] [<ffffffff81cf5672>] ? repair_env_string+0x5e/0x5e [ 0.789138] [<ffffffff81cf5356>] x86_64_start_reservations+0x131/0x135 [ 0.808849] [<ffffffff81cf545a>] x86_64_start_kernel+0x100/0x10f Reported-by: Mark Rustad <mark.d.rustad@intel.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: John Fastabend <john.r.fastabend@intel.com> --- net/core/net_namespace.c | 4 +++- net/core/netprio_cgroup.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html