Re: [PATCH] net: x86: bpf: don't forget to free sk_filter (v2)

From: Alexei Starovoitov
Date: Thu Nov 07 2013 - 12:17:11 EST


On Wed, Nov 6, 2013 at 8:35 PM, Andrey Vagin <avagin@xxxxxxxxxx> wrote:
> sk_filter isn't freed if bpf_func is equal to sk_run_filter.
>
> This memory leak was introduced by v3.12-rc3-224-gd45ed4a4
> "net: fix unsafe set_memory_rw from softirq".
>
> Before this patch sk_filter was freed in sk_filter_release_rcu,
> now it should be freed in bpf_jit_free.
>
> Here is output of kmemleak:
> unreferenced object 0xffff8800b774eab0 (size 128):
> comm "systemd", pid 1, jiffies 4294669014 (age 124.062s)
> hex dump (first 32 bytes):
> 00 00 00 00 0b 00 00 00 20 63 7f b7 00 88 ff ff ........ c......
> 60 d4 55 81 ff ff ff ff 30 d9 55 81 ff ff ff ff `.U.....0.U.....
> backtrace:
> [<ffffffff816444be>] kmemleak_alloc+0x4e/0xb0
> [<ffffffff811845af>] __kmalloc+0xef/0x260
> [<ffffffff81534028>] sock_kmalloc+0x38/0x60
> [<ffffffff8155d4dd>] sk_attach_filter+0x5d/0x190
> [<ffffffff815378a1>] sock_setsockopt+0x991/0x9e0
> [<ffffffff81531bd6>] SyS_setsockopt+0xb6/0xd0
> [<ffffffff8165f3e9>] system_call_fastpath+0x16/0x1b
> [<ffffffffffffffff>] 0xffffffffffffffff
>
> v2: add extra { } after else
>
> Fixes: d45ed4a4e33a ("net: fix unsafe set_memory_rw from softirq")
> Acked-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>
> ---

Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>

Thanks!
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