From: Eric Dumazet <eduma...@google.com>
Recent patch forgot to remove nla_data(), upsetting syzkaller a bit.
BUG: KASAN: slab-out-of-bounds in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314
Read of size 1 at addr ffff8801ad1f4fdd by task syz-executor189/4509
CPU: 1 PID: 4509 Comm: syz-executor189 Not tainted 4.17.0-rc6+ #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
nla_strlcpy+0x13d/0x150 lib/nlattr.c:314
nfnl_acct_new+0x574/0xc50 net/netfilter/nfnetlink_acct.c:118
nfnetlink_rcv_msg+0xdb5/0xff0 net/netfilter/nfnetlink.c:212
netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448
nfnetlink_rcv+0x1fe/0x1ba0 net/netfilter/nfnetlink.c:513
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:639
sock_write_iter+0x35a/0x5a0 net/socket.c:908
call_write_iter include/linux/fs.h:1784 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x64d/0x960 fs/read_write.c:487
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0xf9/0x250 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
Fixes: 4e09fc873d92 ("netfilter: prefer nla_strlcpy for dealing with NLA_STRING
attributes")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Acked-by: Florian Westphal <f...@strlen.de>
Reported-by: syzbot <syzkal...@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
net/netfilter/nfnetlink_acct.c | 2 +-
net/netfilter/nfnetlink_cthelper.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index 6ddf89183e7b..a0e5adf0b3b6 100644
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -115,7 +115,7 @@ static int nfnl_acct_new(struct net *net, struct sock *nfnl,
nfacct->flags = flags;
}
- nla_strlcpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
+ nla_strlcpy(nfacct->name, tb[NFACCT_NAME], NFACCT_NAME_MAX);
if (tb[NFACCT_BYTES]) {
atomic64_set(&nfacct->bytes,
diff --git a/net/netfilter/nfnetlink_cthelper.c
b/net/netfilter/nfnetlink_cthelper.c
index fa026b269b36..cb5b5f207777 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -150,7 +150,7 @@ nfnl_cthelper_expect_policy(struct
nf_conntrack_expect_policy *expect_policy,
return -EINVAL;
nla_strlcpy(expect_policy->name,
- nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
+ tb[NFCTH_POLICY_NAME], NF_CT_HELPER_NAME_LEN);
expect_policy->max_expected =
ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT)
@@ -235,7 +235,7 @@ nfnl_cthelper_create(const struct nlattr * const tb[],
goto err1;
nla_strlcpy(helper->name,
- nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
+ tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN);
size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
if (size > FIELD_SIZEOF(struct nf_conn_help, data)) {
ret = -ENOMEM;
--
2.11.0
