From: Wang Yufen wangyufen@huawei.com
[ Upstream commit 1118b2049d77ca0b505775fc1a8d1909cf19a7ec ]
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 <-- not ask to complete the gro work, will cause memory leaks in <-- following tun_napi_del() ... tun_napi_del() netif_napi_del() __netif_napi_del() <-- &napi->rx_list is not empty, which caused memory leaks
To fix, add napi_complete() after napi_gro_frags().
Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Wang Yufen wangyufen@huawei.com Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0c09f8e9d383..83662f616b67 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1996,6 +1996,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
local_bh_disable(); napi_gro_frags(&tfile->napi); + napi_complete(&tfile->napi); local_bh_enable(); mutex_unlock(&tfile->napi_mutex); } else if (tfile->napi_enabled) {