From: Thorsten Blum Date: Mon, 2 Mar 2026 13:53:40 +0000 (+0100) Subject: x86/mtrr: Use kstrtoul() in parse_mtrr_spare_reg() X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9a4af5a00a8bff84d8d499e43d3424173835173c;p=thirdparty%2Fkernel%2Flinux.git x86/mtrr: Use kstrtoul() in parse_mtrr_spare_reg() Replace the deprecated simple_strtoul()¹ with kstrtoul() for parsing the early boot parameter mtrr_spare_reg_nr. simple_strtoul() silently sets nr_mtrr_spare_reg to 0 for invalid input instead of rejecting it and keeping the default value. Return kstrtoul()'s retval directly to propagate parsing failures instead of treating them as success. Also return -EINVAL when '=' is missing from the boot parameter and 'arg' is NULL. ¹ https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull [ bp: Massage commit message. ] Signed-off-by: Thorsten Blum Signed-off-by: Borislav Petkov (AMD) Link: https://patch.msgid.link/20260302135341.3473-2-thorsten.blum@linux.dev --- diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c index 763534d77f593..e3eee9ae41414 100644 --- a/arch/x86/kernel/cpu/mtrr/cleanup.c +++ b/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -437,9 +437,10 @@ static unsigned long nr_mtrr_spare_reg __initdata = static int __init parse_mtrr_spare_reg(char *arg) { - if (arg) - nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0); - return 0; + if (!arg) + return -EINVAL; + + return kstrtoul(arg, 0, &nr_mtrr_spare_reg); } early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg);