kmemleak reports after running test_progs:
unreferenced object 0xffff8881b1672dc0 (size 232):
comm "test_progs", pid 394388, jiffies 4354712116 (age 841.975s)
hex dump (first 32 bytes):
e0 84 d7 a8 81 88 ff ff 80 2c 67 b1 81 88 ff ff .........,g.....
00 40 c5 9b 81 88 ff ff 00 00 00 00 00 00 00 00 .@..............
backtrace:
[<00000000c8f01748>] napi_skb_cache_get+0xd4/0x150
[<0000000041c7fc09>] __napi_build_skb+0x15/0x50
[<00000000431c7079>] __napi_alloc_skb+0x26e/0x540
[<000000003ecfa30e>] napi_get_frags+0x59/0x140
[<0000000099b2199e>] tun_get_user+0x183d/0x3bb0 [tun]
[<000000008a5adef0>] tun_chr_write_iter+0xc0/0x1b1 [tun]
[<0000000049993ff4>] do_iter_readv_writev+0x19f/0x320
[<000000008f338ea2>] do_iter_write+0x135/0x630
[<000000008a3377a4>] vfs_writev+0x12e/0x440
[<00000000a6b5639a>] do_writev+0x104/0x280
[<00000000ccf065d8>] do_syscall_64+0x3b/0x90
[<00000000d776e329>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
The issue occurs in the following scenarios:
tun_get_user()
napi_gro_frags()
napi_frags_finish()
case GRO_NORMAL:
gro_normal_one()
list_add_tail(&skb->list, &napi->rx_list);
<-- While napi->rx_count < READ_ONCE(gro_normal_batch),
<-- gro_normal_list() is not called, napi->rx_list is not empty
...
netif_napi_del()
__netif_napi_del()
<-- &napi->rx_list is not empty, which caused memory leaks
To fix, add flush_rx_list() to free skbs in napi->rx_list.
Fixes: 323ebb61e32b ("net: use listified RX for handling GRO_NORMAL skbs")
Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx>
---
net/core/dev.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/net/core/dev.c b/net/core/dev.c
index 3be2560..de3bc9c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6461,6 +6461,16 @@ static void flush_gro_hash(struct napi_struct *napi)
}
}
+static void flush_rx_list(struct napi_struct *napi)
+{
+ struct sk_buff *skb, *next;
+
+ list_for_each_entry_safe(skb, next, &napi->rx_list, list) {
+ skb_list_del_init(skb);
+ kfree_skb(skb);
+ }
+}
+
/* Must be called in process context */
void __netif_napi_del(struct napi_struct *napi)
{
@@ -6471,6 +6481,7 @@ void __netif_napi_del(struct napi_struct *napi)
list_del_rcu(&napi->dev_list);
napi_free_frags(napi);
+ flush_rx_list(napi);
flush_gro_hash(napi);
napi->gro_bitmask = 0;
--
1.8.3.1
