6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wang Liang <wangliang74@xxxxxxxxxx>
[ Upstream commit 4f4aa4aa28142d53f8b06585c478476cfe325cfc ]
If inet_csk_reqsk_queue_hash_add() return false, tcp_conn_request() will
return without free the dst memory, which allocated in af_ops->route_req.
Here is the kmemleak stack:
unreferenced object 0xffff8881198631c0 (size 240):
comm "softirq", pid 0, jiffies 4299266571 (age 1802.392s)
hex dump (first 32 bytes):
00 10 9b 03 81 88 ff ff 80 98 da bc ff ff ff ff ................
81 55 18 bb ff ff ff ff 00 00 00 00 00 00 00 00 .U..............
backtrace:
[<ffffffffb93e8d4c>] kmem_cache_alloc+0x60c/0xa80
[<ffffffffba11b4c5>] dst_alloc+0x55/0x250
[<ffffffffba227bf6>] rt_dst_alloc+0x46/0x1d0
[<ffffffffba23050a>] __mkroute_output+0x29a/0xa50
[<ffffffffba23456b>] ip_route_output_key_hash+0x10b/0x240
[<ffffffffba2346bd>] ip_route_output_flow+0x1d/0x90
[<ffffffffba254855>] inet_csk_route_req+0x2c5/0x500
[<ffffffffba26b331>] tcp_conn_request+0x691/0x12c0
[<ffffffffba27bd08>] tcp_rcv_state_process+0x3c8/0x11b0
[<ffffffffba2965c6>] tcp_v4_do_rcv+0x156/0x3b0
[<ffffffffba299c98>] tcp_v4_rcv+0x1cf8/0x1d80
[<ffffffffba239656>] ip_protocol_deliver_rcu+0xf6/0x360
[<ffffffffba2399a6>] ip_local_deliver_finish+0xe6/0x1e0
[<ffffffffba239b8e>] ip_local_deliver+0xee/0x360
[<ffffffffba239ead>] ip_rcv+0xad/0x2f0
[<ffffffffba110943>] __netif_receive_skb_one_core+0x123/0x140
Call dst_release() to free the dst memory when
inet_csk_reqsk_queue_hash_add() return false in tcp_conn_request().
Fixes: ff46e3b44219 ("Fix race for duplicate reqsk on identical SYN")
Signed-off-by: Wang Liang <wangliang74@xxxxxxxxxx>
Link: https://patch.msgid.link/20241219072859.3783576-1-wangliang74@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_input.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2d844e1f867f..2d43b29da15e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -7328,6 +7328,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
if (unlikely(!inet_csk_reqsk_queue_hash_add(sk, req,
req->timeout))) {
reqsk_free(req);
+ dst_release(dst);
return 0;
}
--
2.39.5
