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authorLiping Zhang <zlpnobody@gmail.com>2017-01-07 20:51:50 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2017-01-16 14:23:02 +0100
commitd21e540b4dd74a26df7a66ebab75c693a4a6a861 (patch)
tree64c0279c2c99fad49b78a9c558e6e763b0406035 /net
parent6443ebc3fdd6f3c766d9442c18be274b3d736050 (diff)
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netfilter: nf_tables: fix possible oops when dumping stateful objects
When dumping nft stateful objects, if NFTA_OBJ_TABLE and NFTA_OBJ_TYPE attributes are not specified either, filter will become NULL, so oops will happen(actually nft utility will always set NFTA_OBJ_TABLE attr, so I write a test program to make this happen): BUG: unable to handle kernel NULL pointer dereference at (null) IP: nf_tables_dump_obj+0x17c/0x330 [nf_tables] [...] Call Trace: ? nf_tables_dump_obj+0x5/0x330 [nf_tables] ? __kmalloc_reserve.isra.35+0x31/0x90 ? __alloc_skb+0x5b/0x1e0 netlink_dump+0x124/0x2a0 __netlink_dump_start+0x161/0x190 nf_tables_getobj+0xe8/0x280 [nf_tables] Fixes: a9fea2a3c3cf ("netfilter: nf_tables: allow to filter stateful object dumps by type") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_tables_api.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0db5f9782265..091d2dcc63b2 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4262,10 +4262,11 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
if (idx > s_idx)
memset(&cb->args[1], 0,
sizeof(cb->args) - sizeof(cb->args[0]));
- if (filter->table[0] &&
+ if (filter && filter->table[0] &&
strcmp(filter->table, table->name))
goto cont;
- if (filter->type != NFT_OBJECT_UNSPEC &&
+ if (filter &&
+ filter->type != NFT_OBJECT_UNSPEC &&
obj->type->type != filter->type)
goto cont;