From: Daniel Borkmann <daniel@iogearbox.net>
Date: Thu, 28 Jun 2018 21:34:58 +0000 (+0200)
Subject: bpf, s390: fix potential memleak when later bpf_jit_prog fails
X-Git-Tag: v4.17.19~175
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b641c52ae260e79ddc4ae3af946078314b46e218;p=thirdparty%2Fkernel%2Fstable.git

bpf, s390: fix potential memleak when later bpf_jit_prog fails

[ Upstream commit f605ce5eb26ac934fb8106d75d46a2c875a2bf23 ]

If we would ever fail in the bpf_jit_prog() pass that writes the
actual insns to the image after we got header via bpf_jit_binary_alloc()
then we also need to make sure to free it through bpf_jit_binary_free()
again when bailing out. Given we had prior bpf_jit_prog() passes to
initially probe for clobbered registers, program size and to fill in
addrs arrray for jump targets, this is more of a theoretical one,
but at least make sure this doesn't break with future changes.

Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index dd2bcf0e7d00d..7b08b0ffa2c70 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -1391,6 +1391,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 		goto free_addrs;
 	}
 	if (bpf_jit_prog(&jit, fp)) {
+		bpf_jit_binary_free(header);
 		fp = orig_fp;
 		goto free_addrs;
 	}