From: Alexei Starovoitov <ast@kernel.org>
Date: Wed, 30 Oct 2019 16:30:19 -0700
Subject: bpf: Fix bpf jit kallsym access
Patch-mainline: Queued in subsystem maintainer repository
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: af91acbc62999d62e2ca1e80f660d20561ca55d3
References: bsc#1155518
Jiri reported crash when JIT is on, but net.core.bpf_jit_kallsyms is off.
bpf_prog_kallsyms_find() was skipping addr->bpf_prog resolution
logic in oops and stack traces. That's incorrect.
It should only skip addr->name resolution for 'cat /proc/kallsyms'.
That's what bpf_jit_kallsyms and bpf_jit_harden protect.
Fixes: 3dec541b2e63 ("bpf: Add support for BTF pointers to x86 JIT")
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191030233019.1187404-1-ast@kernel.org
Acked-by: Gary Lin <glin@suse.com>
---
kernel/bpf/core.c | 3 ---
1 file changed, 3 deletions(-)
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -668,9 +668,6 @@ static struct bpf_prog *bpf_prog_kallsym
{
struct latch_tree_node *n;
- if (!bpf_jit_kallsyms_enabled())
- return NULL;
-
n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
return n ?
container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :