On Tue, Jun 09, 2020 at 02:58:12PM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:7ae77150 Merge tag 'powerpc-5.8-1' of git://git.kernel.org..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=128a9df210
> kernel config: https://syzkaller.appspot.com/x/.config?x=9a1aa05456dfd557
> dashboard link: https://syzkaller.appspot.com/bug?extid=b005af2cfb0411e617de
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17304a9610
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=168a9df210
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+b005af2cfb0411e61...@syzkaller.appspotmail.com
>
> executing program
> executing program
> executing program
> BUG: memory leak
> unreferenced object 0x88811c797900 (size 128):
> comm "syz-executor256", pid 6458, jiffies 4294947022 (age 13.050s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> backtrace:
> [<4276332a>] kmalloc include/linux/slab.h:555 [inline]
> [<4276332a>] kzalloc include/linux/slab.h:669 [inline]
> [<4276332a>] ctnetlink_alloc_filter+0x3a/0x2a0
> net/netfilter/nf_conntrack_netlink.c:924
> [<0047e6fb>] ctnetlink_start+0x3a/0x80
> net/netfilter/nf_conntrack_netlink.c:998
> [] __netlink_dump_start+0x1a3/0x2e0
> net/netlink/af_netlink.c:2343
> [<16b073fa>] netlink_dump_start include/linux/netlink.h:246
> [inline]
> [<16b073fa>] ctnetlink_get_conntrack+0x26d/0x2f0
> net/netfilter/nf_conntrack_netlink.c:1611
> [] nfnetlink_rcv_msg+0x32f/0x370
> net/netfilter/nfnetlink.c:229
> [<08feca87>] netlink_rcv_skb+0x5a/0x180
> net/netlink/af_netlink.c:2469
> [<88caad78>] nfnetlink_rcv+0x83/0x1b0
> net/netfilter/nfnetlink.c:563
> [<52160488>] netlink_unicast_kernel net/netlink/af_netlink.c:1303
> [inline]
> [<52160488>] netlink_unicast+0x20a/0x2f0
> net/netlink/af_netlink.c:1329
> [] netlink_sendmsg+0x2b5/0x560
> net/netlink/af_netlink.c:1918
> [] sock_sendmsg_nosec net/socket.c:652 [inline]
> [] sock_sendmsg+0x4c/0x60 net/socket.c:672
> [] sys_sendmsg+0x2c4/0x2f0 net/socket.c:2352
> [<5bba2f8d>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2406
> [<60ac6563>] __sys_sendmsg+0x77/0xe0 net/socket.c:2439
> [<2f7b34b0>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
> [<941009bb>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Hm, filter is not released in the error path.
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index d7bd8b1f27d5..832eabecfbdd 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -939,7 +939,8 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
filter->mark.mask = 0x;
}
} else if (cda[CTA_MARK_MASK]) {
- return ERR_PTR(-EINVAL);
+ err = -EINVAL;
+ goto err_filter;
}
#endif
if (!cda[CTA_FILTER])
@@ -947,15 +948,17 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
err = ctnetlink_parse_zone(cda[CTA_ZONE], >zone);
if (err < 0)
- return ERR_PTR(err);
+ goto err_filter;
err = ctnetlink_parse_filter(cda[CTA_FILTER], filter);
if (err < 0)
- return ERR_PTR(err);
+ goto err_filter;
if (filter->orig_flags) {
- if (!cda[CTA_TUPLE_ORIG])
- return ERR_PTR(-EINVAL);
+ if (!cda[CTA_TUPLE_ORIG]) {
+ err = -EINVAL;
+ goto err_filter;
+ }
err = ctnetlink_parse_tuple_filter(cda, >orig,
CTA_TUPLE_ORIG,
@@ -963,23 +966,32 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
>zone,
filter->orig_flags);
if (err < 0)
- return ERR_PTR(err);
+ goto err_filter;
}
if (filter->reply_flags) {
- if (!cda[CTA_TUPLE_REPLY])
- return ERR_PTR(-EINVAL);
+ if (!cda[CTA_TUPLE_REPLY]) {
+ err = -EINVAL;
+ goto err_filter;
+ }
err = ctnetlink_parse_tuple_filter(cda, >reply,
CTA_TUPLE_REPLY,
filter->family,
>zone,
filter->orig_flags);
- if (err < 0)
- return ERR_PTR(err);
+ if (err < 0) {
+ err = -EINVAL;
+ goto err_filter;
+ }
}
return filter;
+
+err_filter:
+ kfree(filter);
+
+ return ERR_PTR(err);
}
static bool ctnetlink_needs_filter(u8 family, const struct nlattr * const *cda)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 073aa1051d43..5792e9dcd9bc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6550,12 +6550,22 @@ static int nf_tables_newflowtable(struct
