Hello.
On 7/24/2016 5:31 AM, Tetsuo Handa wrote:
kmemcheck complains that some of struct nf_hook_ops members allocated at
xt_hook_ops_alloc() are not initialized before nf_register_net_hook() is
called. Add __GFP_ZERO to initialize explicitly.
[ 367.411936] nf_conntrack version 0.5.0 (6144 buckets, 24576 max)
[ 367.458540] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 367.463977] WARNING: kmemcheck: Caught 64-bit read from uninitialized memory
(ffff88003af7f300)
[ 367.465633] 00000000000000000000000000000000303f5381ffffffff0000000000000000
[ 367.468185] u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u
[ 367.470687] ^
[ 367.471079] RIP: 0010:[<ffffffff814caa0f>] [<ffffffff814caa0f>]
nf_register_net_hook+0x2f/0x160
[ 367.472846] RSP: 0018:ffff88003f5abcb0 EFLAGS: 00010286
[ 367.473821] RAX: ffff88003adb73c0 RBX: ffff88003af7f300 RCX: 0000000000000000
[ 367.475122] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88003adb7400
[ 367.476485] RBP: ffff88003f5abcc8 R08: 0000000000000067 R09: 0000000000000000
[ 367.477764] R10: ffff88003adb83c0 R11: 0000000000000000 R12: ffffffff81876760
[ 367.479053] R13: ffff88003adb73c0 R14: 0000000000000003 R15: ffff88003af7f300
[ 367.480351] FS: 0000000000000000(0000) GS:ffffffff8182c000(0000)
knlGS:0000000000000000
[ 367.482018] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 367.483069] CR2: ffff88003f404280 CR3: 000000003ad30000 CR4: 00000000001406f0
[ 367.484357] [<ffffffff814cadec>] nf_register_net_hooks+0x3c/0xa0
[ 367.485617] [<ffffffff8153328f>] ipt_register_table+0xef/0x130
[ 367.486765] [<ffffffff81533ec1>] iptable_filter_table_init.part.1+0x51/0x70
[ 367.488125] [<ffffffff81533f2a>] iptable_filter_net_init+0x2a/0x30
[ 367.489375] [<ffffffff8148f58c>] ops_init+0x3c/0x130
[ 367.490410] [<ffffffff8148f8c8>] register_pernet_operations+0x108/0x1c0
[ 367.491746] [<ffffffff8148f9a3>] register_pernet_subsys+0x23/0x40
[ 367.492933] [<ffffffff818d5e25>] iptable_filter_init+0x33/0x4b
[ 367.494053] [<ffffffff8100041a>] do_one_initcall+0x4a/0x180
[ 367.495168] [<ffffffff818981d0>] kernel_init_freeable+0x15b/0x201
[ 367.496332] [<ffffffff8159eff9>] kernel_init+0x9/0x100
[ 367.497369] [<ffffffff815a9c0f>] ret_from_fork+0x1f/0x40
[ 367.498449] [<ffffffffffffffff>] 0xffffffffffffffff
[ 367.499523] Initializing XFRM netlink socket
[ 367.500404] NET: Registered protocol family 10
[ 367.501792] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 367.502971] NET: Registered protocol family 17
Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
---
net/netfilter/x_tables.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index e0aa7c1..fc261fe 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1513,7 +1513,7 @@ xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn
*fn)
if (!num_hooks)
return ERR_PTR(-EINVAL);
- ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
+ ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL | __GFP_ZERO);
Why not just use kzalloc() or even kcalloc()?
[...]
MBR, Sergei
