[PATCH AUTOSEL 5.4 114/459] bpftool: Don't crash on missing xlated program instructions
From: Sasha Levin <sashal@kernel.org>
Date: 2020-02-14 17:38:26
Also in:
bpf, lkml, stable
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
From: Toke Høiland-Jørgensen <redacted>
[ Upstream commit d95f1e8b462c4372ac409886070bb8719d8a4d3a ]
Turns out the xlated program instructions can also be missing if
kptr_restrict sysctl is set. This means that the previous fix to check the
jited_prog_insns pointer was insufficient; add another check of the
xlated_prog_insns pointer as well.
Fixes: 5b79bcdf0362 ("bpftool: Don't crash on missing jited insns or ksyms")
Fixes: cae73f233923 ("bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()")
Signed-off-by: Toke Høiland-Jørgensen <redacted>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <redacted>
Link: https://lore.kernel.org/bpf/20200206102906.112551-1-toke@redhat.com (local)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/bpf/bpftool/prog.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index ea0bcd58bcb9a..2e388421c32f4 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c@@ -500,7 +500,7 @@ static int do_dump(int argc, char **argv) buf = (unsigned char *)(info->jited_prog_insns); member_len = info->jited_prog_len; } else { /* DUMP_XLATED */ - if (info->xlated_prog_len == 0) { + if (info->xlated_prog_len == 0 || !info->xlated_prog_insns) { p_err("error retrieving insn dump: kernel.kptr_restrict set?"); goto err_free; }
--
2.20.1