Re: [GIT PULL] Networking for v6.13-rc7

Catalin Marinas
2025-01-18T13:45:22Z

On Thu, Jan 16, 2025 at 07:38:21PM -0800, Jakub Kicinski wrote:
> On Thu, 09 Jan 2025 23:21:07 +0000 pr-tracker-bot@kernel.org wrote:
> > The pull request you sent on Thu, 9 Jan 2025 10:29:53 -0800:
> >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git tags/net-6.13-rc7
> >
> > has been merged into torvalds/linux.git:
> > https://git.kernel.org/torvalds/c/c77cd47cee041bc1664b8e5fcd23036e5aab8e2a
>
> Hi Linus!
>
> After 76d5d4c53e68 ("mm/kmemleak: fix percpu memory leak detection
> failure") we get this on every instance of our testing VMs:
>
> unreferenced object 0x00042aa0 (size 64):
> comm "swapper/0", pid 0, jiffies 4294667296
> hex dump (first 32 bytes on cpu 2):
> 00 00 00 00 00 00 00 00 00 00 06 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace (crc 0):
> pcpu_alloc_noprof+0x4ad/0xab0
> setup_zone_pageset+0x30/0x290
> setup_per_cpu_pageset+0x6a/0x1f0
> start_kernel+0x2a4/0x410
> x86_64_start_reservations+0x18/0x30
> x86_64_start_kernel+0xba/0x110
> common_startup_64+0x12c/0x138

I doubt that's related to the networking pull request but I can see it
caused by the above commit, now that we track per-cpu allocations. Most
likely it's a false positive. I'll try to reproduce it next week but
something like below might fix (untested):

diff --git a/mm/numa.c b/mm/numa.c
index e2eec07707d1..c594d853cfe8 100644
--- a/mm/numa.c
+++ b/mm/numa.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-or-later

+#include <linux/kmemleak.h>
#include <linux/memblock.h>
#include <linux/printk.h>
#include <linux/numa.h>
@@ -23,6 +24,9 @@ void __init alloc_node_data(int nid)
nd_size, nid);
nd = __va(nd_pa);

+ /* needed to track related allocation stored in node_data[] */
+ kmemleak_alloc(nd, nd_size, 0, 0);
+
/* report and initialize */
pr_info("NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
nd_pa, nd_pa + nd_size - 1);

--
Catalin