From 7469cebbd810774056efbf215fb2f82040d4b526 Mon Sep 17 00:00:00 2001 From: Fernando Fernandez Mancera Date: Mon, 22 Jun 2026 15:08:53 +0200 Subject: [PATCH] ipv6: fix error handling in ignore_routes_with_linkdown sysctl [ Upstream commit cf4f2b14401f29ccac56393ca9e4b42a2505f540 ] When writing to the ignore_routes_with_linkdown sysctl, if proc_dointvec() fails to parse the input, it returns a negative error code. The current implementation is overwriting that error for write operations. This results in a silent failure, it returns a successful write although the configuration was not modified at all. When modifying the "all" variant it can also modify the configuration of existing interfaces to the wrong value. Fix this by checking the return value of proc_dointvec() and returning early on failure. Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") Reviewed-by: Nicolas Dichtel Signed-off-by: Fernando Fernandez Mancera Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260622130857.5115-3-fmancera@suse.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/addrconf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index e8ca9f56658e..cd981fbbc60a 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -6639,6 +6639,8 @@ int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl, lctl.data = &val; ret = proc_dointvec(&lctl, write, buffer, lenp, ppos); + if (ret) + return ret; if (write) ret = addrconf_fixup_linkdown(ctl, valp, val);