From 76167e5c5457aee8fba3edc5b8554183696fc94d Mon Sep 17 00:00:00 2001 From: Arvind Sankar Date: Sun, 2 Aug 2020 21:15:34 -0400 Subject: x86/kaslr: Replace strlen() with strnlen() strnlen is safer in case the command line is not NUL-terminated. Signed-off-by: Arvind Sankar Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200803011534.730645-2-nivedita@alum.mit.edu --- arch/x86/boot/compressed/kaslr.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 735fcb2a8b7b..6d397435ccad 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -43,6 +43,10 @@ #define STATIC #include +#define _SETUP +#include /* For COMMAND_LINE_SIZE */ +#undef _SETUP + #ifdef CONFIG_X86_5LEVEL unsigned int __pgtable_l5_enabled; unsigned int pgdir_shift __ro_after_init = 39; @@ -278,7 +282,7 @@ static void handle_mem_options(void) if (!args) return; - len = strlen(args); + len = strnlen(args, COMMAND_LINE_SIZE-1); tmp_cmdline = malloc(len + 1); if (!tmp_cmdline) error("Failed to allocate space for tmp_cmdline"); @@ -425,7 +429,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, cmd_line = get_cmd_line_ptr(); /* Calculate size of cmd_line. */ if (cmd_line) { - cmd_line_size = strlen((char *)cmd_line) + 1; + cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1; mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line; mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size; add_identity_map(mem_avoid[MEM_AVOID_CMDLINE].start, -- cgit v1.2.3