6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Catalin Marinas catalin.marinas@arm.com
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@arm.com Fixes: 84c326299191 ("mm: kmemleak: check physical address when scan") Signed-off-by: Catalin Marinas catalin.marinas@arm.com Reported-by: Jakub Kicinski kuba@kernel.org Tested-by: Matthieu Baerts (NGI0) matttbe@kernel.org Cc: Patrick Wang patrick.wang.shcn@gmail.com Cc: stable@vger.kernel.org [6.0.x] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1549,7 +1549,7 @@ 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); }