nf_tables: fix NULL pointer dereference in nft_inner_init()

We should check whether the NFTA_INNER_NUM netlink attribute is present
before accessing it, otherwise a null pointer deference error will occur.

Call Trace:
 dump_stack_lvl+0x4f/0x90
 print_report+0x3f0/0x620
 kasan_report+0xcd/0x110
 __asan_load4+0x84/0xa0
 nft_inner_init+0x128/0x2e0
 nf_tables_newrule+0x813/0x1230
 nfnetlink_rcv_batch+0xec3/0x1170
 nfnetlink_rcv+0x1e4/0x220
 netlink_unicast+0x34e/0x4b0
 netlink_sendmsg+0x45c/0x7e0
 __sys_sendto+0x355/0x370
 __x64_sys_sendto+0x84/0xa0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fixes: 3a07327d10 ("netfilter: nft_inner: support for inner tunnel header matching")
Signed-off-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
This commit is contained in:
Xingyuan Mo 2023-10-09 18:36:14 +08:00 committed by Florian Westphal
parent 4c90bba60c
commit 52177bbf19

View file

@ -298,6 +298,7 @@ static int nft_inner_init(const struct nft_ctx *ctx,
int err;
if (!tb[NFTA_INNER_FLAGS] ||
!tb[NFTA_INNER_NUM] ||
!tb[NFTA_INNER_HDRSIZE] ||
!tb[NFTA_INNER_TYPE] ||
!tb[NFTA_INNER_EXPR])