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| author | Daniel Borkmann <daniel@iogearbox.net> | 2023-08-25 15:49:45 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-08-28 10:18:03 +0100 |
| commit | 28d18b673ffa2d13112ddb6e4c32c60d9b0cda50 (patch) | |
| tree | cb0f5479a968f4002f37b57331d82627744e934d /net/core/dev.c | |
| parent | b9a341123937799157aa415cf3a60eb7f57d634f (diff) | |
| download | linux-28d18b673ffa2d13112ddb6e4c32c60d9b0cda50.tar.gz | |
net: Fix skb consume leak in sch_handle_egress
Fix a memory leak for the tc egress path with TC_ACT_{STOLEN,QUEUED,TRAP}:
[...]
unreferenced object 0xffff88818bcb4f00 (size 232):
comm "softirq", pid 0, jiffies 4299085078 (age 134.028s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 80 70 61 81 88 ff ff 00 41 31 14 81 88 ff ff ..pa.....A1.....
backtrace:
[<ffffffff9991b938>] kmem_cache_alloc_node+0x268/0x400
[<ffffffff9b3d9231>] __alloc_skb+0x211/0x2c0
[<ffffffff9b3f0c7e>] alloc_skb_with_frags+0xbe/0x6b0
[<ffffffff9b3bf9a9>] sock_alloc_send_pskb+0x6a9/0x870
[<ffffffff9b6b3f00>] __ip_append_data+0x14d0/0x3bf0
[<ffffffff9b6ba24e>] ip_append_data+0xee/0x190
[<ffffffff9b7e1496>] icmp_push_reply+0xa6/0x470
[<ffffffff9b7e4030>] icmp_reply+0x900/0xa00
[<ffffffff9b7e42e3>] icmp_echo.part.0+0x1a3/0x230
[<ffffffff9b7e444d>] icmp_echo+0xcd/0x190
[<ffffffff9b7e9566>] icmp_rcv+0x806/0xe10
[<ffffffff9b699bd1>] ip_protocol_deliver_rcu+0x351/0x3d0
[<ffffffff9b699f14>] ip_local_deliver_finish+0x2b4/0x450
[<ffffffff9b69a234>] ip_local_deliver+0x174/0x1f0
[<ffffffff9b69a4b2>] ip_sublist_rcv_finish+0x1f2/0x420
[<ffffffff9b69ab56>] ip_sublist_rcv+0x466/0x920
[...]
I was able to reproduce this via:
ip link add dev dummy0 type dummy
ip link set dev dummy0 up
tc qdisc add dev eth0 clsact
tc filter add dev eth0 egress protocol ip prio 1 u32 match ip protocol 1 0xff action mirred egress redirect dev dummy0
ping 1.1.1.1
<stolen>
After the fix, there are no kmemleak reports with the reproducer. This is
in line with what is also done on the ingress side, and from debugging the
skb_unref(skb) on dummy xmit and sch_handle_egress() side, it is visible
that these are two different skbs with both skb_unref(skb) as true. The two
seen skbs are due to mirred doing a skb_clone() internally as use_reinsert
is false in tcf_mirred_act() for egress. This was initially reported by Gal.
Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support")
Reported-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/bdfc2640-8f65-5b56-4472-db8e2b161aab@nvidia.com
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 17e6281e408c7..9f6ed6d97f89d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4061,6 +4061,7 @@ egress_verdict: case TC_ACT_STOLEN: case TC_ACT_QUEUED: case TC_ACT_TRAP: + consume_skb(skb); *ret = NET_XMIT_SUCCESS; return NULL; } |