netdev - [PATCH bpf] tools/bpftool: fix attaching flow dissector

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  5 Nov 2020 11:52:30 +0000
From:   Lorenz Bauer <lmb@...udflare.com>
To:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Lorenz Bauer <lmb@...udflare.com>
Cc:     kernel-team@...udflare.com, Jiri Benc <jbenc@...hat.com>,
        netdev@...r.kernel.org, bpf@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH bpf] tools/bpftool: fix attaching flow dissector

My earlier patch to reject non-zero arguments to flow dissector attach
broke attaching via bpftool. Instead of 0 it uses -1 for target_fd.
Fix this by passing a zero argument when attaching the flow dissector.

Fixes: 1b514239e859 ("bpf: flow_dissector: Check value of unused flags to BPF_PROG_ATTACH")
Reported-by: Jiri Benc <jbenc@...hat.com>
Signed-off-by: Lorenz Bauer <lmb@...udflare.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 d942c1e3372c..acdb2c245f0a 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -940,7 +940,7 @@ static int parse_attach_detach_args(int argc, char **argv, int *progfd,
 	}
 
 	if (*attach_type == BPF_FLOW_DISSECTOR) {
-		*mapfd = -1;
+		*mapfd = 0;
 		return 0;
 	}
 
-- 
2.25.1