6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Catalin Marinas <catalin.marinas@xxxxxxx>
commit 488b5b9eca68497b533ced059be5eff19578bbca upstream.
Memblock allocations are registered by kmemleak separately, based on their
physical address. During the scanning stage, it checks whether an object
is within the min_low_pfn and max_low_pfn boundaries and ignores it
otherwise.
With the recent addition of __percpu pointer leak detection (commit
6c99d4eb7c5e ("kmemleak: enable tracking for percpu pointers")), kmemleak
started reporting leaks in setup_zone_pageset() and
setup_per_cpu_pageset(). These were caused by the node_data[0] object
(initialised in alloc_node_data()) ending on the PFN_PHYS(max_low_pfn)
boundary. The non-strict upper boundary check introduced by commit
84c326299191 ("mm: kmemleak: check physical address when scan") causes the
pg_data_t object to be ignored (not scanned) and the __percpu pointers it
contains to be reported as leaks.
Make the max_low_pfn upper boundary check strict when deciding whether to
ignore a physical address object and not scan it.
Link: https://lkml.kernel.org/r/20250127184233.2974311-1-catalin.marinas@xxxxxxx
Fixes: 84c326299191 ("mm: kmemleak: check physical address when scan")
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reported-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Tested-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Cc: Patrick Wang <patrick.wang.shcn@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [6.0.x]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/kmemleak.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1689,7 +1689,7 @@ static void kmemleak_scan(void)
unsigned long phys = object->pointer;
if (PHYS_PFN(phys) < min_low_pfn ||
- PHYS_PFN(phys + object->size) >= max_low_pfn)
+ PHYS_PFN(phys + object->size) > max_low_pfn)
__paint_it(object, KMEMLEAK_BLACK);
}
