B.A.T.M.A.N Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: Sven Eckelmann <sven@narfation.org>
Subject: [PATCH 02/12] batctl: netlink: abort netlink_print_common when message allocation fails
Date: Wed, 08 Jul 2026 22:00:08 +0200	[thread overview]
Message-ID: <20260708-bugfixes-netlink-v1-2-8ce03e37f17b@narfation.org> (raw)
In-Reply-To: <20260708-bugfixes-netlink-v1-0-8ce03e37f17b@narfation.org>

When nlmsg_alloc() fails, netlink_print_common() just continues. In
one-shot mode this leaves the loop with the stale last_err of 0 and the
command reports success even though nothing was queried or printed. In
watch mode the loop retries immediately without the usleep() pause and
leaks the header that netlink_get_info() prepared in the previous
iteration.

Treat the allocation failure as -ENOMEM and leave the query loop.

Fixes: d8dd1ff1a0fe ("batctl: Use netlink to replace some of debugfs")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 netlink.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/netlink.c b/netlink.c
index 4a3ab60..cb65655 100644
--- a/netlink.c
+++ b/netlink.c
@@ -567,8 +567,10 @@ int netlink_print_common(struct state *state, char *orig_iface, int read_opt,
 								 header);
 
 		msg = nlmsg_alloc();
-		if (!msg)
-			continue;
+		if (!msg) {
+			last_err = -ENOMEM;
+			break;
+		}
 
 		genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, state->batadv_family,
 			    0, NLM_F_DUMP, nl_cmd, 1);

-- 
2.47.3


  parent reply	other threads:[~2026-07-08 20:03 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-08 20:00 [PATCH 00/12] batctl: netlink bugfixes Sven Eckelmann
2026-07-08 20:00 ` [PATCH 01/12] batctl: handle netlink callback object on error Sven Eckelmann
2026-07-08 20:00 ` Sven Eckelmann [this message]
2026-07-08 20:00 ` [PATCH 03/12] batctl: netlink: don't format NULL extra_info in info_callback Sven Eckelmann
2026-07-08 20:00 ` [PATCH 04/12] batctl: netlink: report dump errors signalled in the NLMSG_DONE message Sven Eckelmann
2026-07-08 20:00 ` [PATCH 05/12] batctl: netlink: detect receive errors in netlink_print_common Sven Eckelmann
2026-07-08 20:00 ` [PATCH 06/12] batctl: netlink: report kernel errors when writing settings Sven Eckelmann
2026-07-08 20:00 ` [PATCH 07/12] batctl: netlink: report send errors in netlink_simple_request Sven Eckelmann
2026-07-08 20:00 ` [PATCH 08/12] batctl: netlink: detect receive errors in query_rtnl_link Sven Eckelmann
2026-07-08 20:00 ` [PATCH 09/12] batctl: netlink: detect receive errors in netlink_simple_request Sven Eckelmann
2026-07-08 20:00 ` [PATCH 10/12] batctl: netlink: detect receive errors in query_rtnl_link_single Sven Eckelmann
2026-07-08 20:00 ` [PATCH 11/12] batctl: netlink: report error on query_rtnl_link send failure Sven Eckelmann
2026-07-08 20:00 ` [PATCH 12/12] batctl: netlink: use kernel-style error codes for nl_recvmsgs Sven Eckelmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260708-bugfixes-netlink-v1-2-8ce03e37f17b@narfation.org \
    --to=sven@narfation.org \
    --cc=b.a.t.m.a.n@lists.open-mesh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox