From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: daniel@iogearbox.net, ast@fb.com
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
bpf@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH bpf] bpftool: Don't crash on missing xlated program instructions
Date: Thu, 6 Feb 2020 11:29:06 +0100 [thread overview]
Message-ID: <20200206102906.112551-1-toke@redhat.com> (raw)
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 <toke@redhat.com>
---
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 a3521deca869..b352ab041160 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -536,7 +536,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
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?");
return -1;
}
--
2.25.0
next reply other threads:[~2020-02-06 10:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 10:29 Toke Høiland-Jørgensen [this message]
2020-02-06 17:52 ` [PATCH bpf] bpftool: Don't crash on missing xlated program instructions Quentin Monnet
2020-02-07 21:50 ` Daniel Borkmann
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