The physical address may exceed 32 bits on ARM(when ARM_LPAE enabled), use PFN_PHYS() in devmem_is_allowed(), or the physical address may overflow and be truncated.
This bug was initially introduced from v2.6.37, and the function was moved to lib when v5.11.
Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem") Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") Cc: stable@vger.kernel.org # v2.6.37 Signed-off-by: Liang Wang wangliang101@huawei.com --- v2: update subject and changelog lib/devmem_is_allowed.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c index c0d67c541849..60be9e24bd57 100644 --- a/lib/devmem_is_allowed.c +++ b/lib/devmem_is_allowed.c @@ -19,7 +19,7 @@ */ int devmem_is_allowed(unsigned long pfn) { - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) + if (iomem_is_exclusive(PFN_PHYS(pfn))) return 0; if (!page_is_ram(pfn)) return 1;