[ANNOUNCE] 5.10.252-rt148

[ANNOUNCE] 5.10.252-rt148

[Luis Claudio R. Goncalves]

Hello RT-list!

I'm pleased to announce the 5.10.252-rt148 stable release.

This release is an RT-only update. All the changes here are specific to RT.

You can get this release via the git tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

  branch: v5.10-rt
  Head SHA1: 226bc47dbb388ecf009cd2569e44b0c2c2125c7e

Or to build 5.10.252-rt148 directly, the following patches should be applied:

  https://www.kernel.org/pub/linux/kernel/v5.x/linux-5.10.tar.xz

  https://www.kernel.org/pub/linux/kernel/v5.x/patch-5.10.252.xz

  https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patch-5.10.252-rt148.patch.xz

Signing key fingerprint:

  9354 0649 9972 8D31 D464  D140 F394 A423 F8E6 7C26

All keys used for the above files and repositories can be found on the
following git repository:

   git://git.kernel.org/pub/scm/docs/kernel/pgpkeys.git

Enjoy!
Luis

Changes from v5.10.252-rt147:
---

Jiayuan Chen (1):
      ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT

Luis Claudio R. Goncalves (1):
      Linux 5.10.252-rt148
---
localversion-rt  |  2 +-
 net/ipv6/route.c | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)
---
diff --git a/localversion-rt b/localversion-rt
index d3fa072b6b43..857407b62668 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt147
+-rt148
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b47f89600c2f..455f76f07e2e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1419,7 +1419,18 @@ static struct rt6_info *rt6_make_pcpu_route(struct net *net,
 
 	p = this_cpu_ptr(res->nh->rt6i_pcpu);
 	prev = cmpxchg(p, NULL, pcpu_rt);
-	BUG_ON(prev);
+	if (unlikely(prev)) {
+		/*
+		 * Another task on this CPU already installed a pcpu_rt.
+		 * This can happen on PREEMPT_RT where preemption is possible.
+		 * Free our allocation and return the existing one.
+		 */
+		WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_RT));
+
+		dst_dev_put(&pcpu_rt->dst);
+		dst_release(&pcpu_rt->dst);
+		return prev;
+	}
 
 	if (res->f6i->fib6_destroying) {
 		struct fib6_info *from;