This is a note to let you know that I've just added the patch titled net/ipv6: Fix the RT cache flush via sysctl using a previous delay to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ipv6-fix-the-rt-cache-flush-via-sysctl-using-a-p.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit cdc964e3344b88619b8925ccec0c6ac4392af4d5 Author: Petr Pavlu <petr.pavlu@xxxxxxxx> Date: Fri Jun 7 13:28:28 2024 +0200 net/ipv6: Fix the RT cache flush via sysctl using a previous delay [ Upstream commit 14a20e5b4ad998793c5f43b0330d9e1388446cf3 ] The net.ipv6.route.flush system parameter takes a value which specifies a delay used during the flush operation for aging exception routes. The written value is however not used in the currently requested flush and instead utilized only in the next one. A problem is that ipv6_sysctl_rtcache_flush() first reads the old value of net->ipv6.sysctl.flush_delay into a local delay variable and then calls proc_dointvec() which actually updates the sysctl based on the provided input. Fix the problem by switching the order of the two operations. Fixes: 4990509f19e8 ("[NETNS][IPV6]: Make sysctls route per namespace.") Signed-off-by: Petr Pavlu <petr.pavlu@xxxxxxxx> Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240607112828.30285-1-petr.pavlu@xxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 627431722f9d6..d305051e8ab5f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6335,12 +6335,12 @@ static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write, if (!write) return -EINVAL; - net = (struct net *)ctl->extra1; - delay = net->ipv6.sysctl.flush_delay; ret = proc_dointvec(ctl, write, buffer, lenp, ppos); if (ret) return ret; + net = (struct net *)ctl->extra1; + delay = net->ipv6.sysctl.flush_delay; fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0); return 0; }