From: Lokesh Dhoundiyal lokesh.dhoundiyal@alliedtelesis.co.nz
[ Upstream commit 9e6c6d17d1d6a3f1515ce399f9a011629ec79aa0 ]
kmemleak reports the following when routing multicast traffic over an ipsec tunnel.
Kmemleak output: unreferenced object 0x8000000044bebb00 (size 256): comm "softirq", pid 0, jiffies 4294985356 (age 126.810s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t. 80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f83947e0>] __kmalloc+0x1e8/0x300 [<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58 [<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8 [<00000000824f6cf1>] gre_rcv+0x178/0x540 [<00000000ccd4e162>] gre_rcv+0x7c/0xd8 [<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350 [<000000006a483377>] ip_local_deliver_finish+0x54/0x68 [<00000000d9271b3a>] ip_local_deliver+0x128/0x168 [<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8 [<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0 [<0000000062e9c336>] __do_softirq+0x1fc/0x3e0 [<00000000013d7914>] irq_exit+0xc4/0xe0 [<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108 [<000000000751eb8e>] handle_int+0x16c/0x178 [<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28
The metadata dst is leaked when ip_route_input_mc() updates the dst for the skb. Commit f38a9eb1f77b ("dst: Metadata destinations") correctly handled dropping the dst in ip_route_input_slow() but missed the multicast case which is handled by ip_route_input_mc(). Drop the dst in ip_route_input_mc() avoiding the leak.
Fixes: f38a9eb1f77b ("dst: Metadata destinations") Signed-off-by: Lokesh Dhoundiyal lokesh.dhoundiyal@alliedtelesis.co.nz Signed-off-by: Chris Packham chris.packham@alliedtelesis.co.nz Reviewed-by: David Ahern dsahern@kernel.org Link: https://lore.kernel.org/r/20220505020017.3111846-1-chris.packham@alliedteles... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/route.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d1feec97fa06..9280e5087159 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1775,6 +1775,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, #endif RT_CACHE_STAT_INC(in_slow_mc);
+ skb_dst_drop(skb); skb_dst_set(skb, &rth->dst); return 0; }