The following commit has been merged into the x86/kaslr branch of tip:
Commit-ID: 709709ac6410f4a14ded158a4b23b979e33e10fb
Gitweb: https://git.kernel.org/tip/709709ac6410f4a14ded158a4b23b979e33e10fb
Author: Arvind Sankar <nivedita@xxxxxxxxxxxx>
AuthorDate: Mon, 27 Jul 2020 19:07:54 -04:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 31 Jul 2020 11:07:51 +02:00
x86/kaslr: Make command line handling safer
Handle the possibility that the command line is NULL.
Replace open-coded strlen with a function call.
Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200727230801.3468620-2-nivedita@xxxxxxxxxxxx
---
arch/x86/boot/compressed/kaslr.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index d7408af..e0f69f3 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -268,15 +268,19 @@ static void parse_gb_huge_pages(char *param, char *val)
static void handle_mem_options(void)
{
char *args = (char *)get_cmd_line_ptr();
- size_t len = strlen((char *)args);
+ size_t len;
char *tmp_cmdline;
char *param, *val;
u64 mem_size;
+ if (!args)
+ return;
+
if (!strstr(args, "memmap=") && !strstr(args, "mem=") &&
!strstr(args, "hugepages"))
return;
+ len = strlen(args);
tmp_cmdline = malloc(len + 1);
if (!tmp_cmdline)
error("Failed to allocate space for tmp_cmdline");
@@ -399,8 +403,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
{
unsigned long init_size = boot_params->hdr.init_size;
u64 initrd_start, initrd_size;
- u64 cmd_line, cmd_line_size;
- char *ptr;
+ unsigned long cmd_line, cmd_line_size;
/*
* Avoid the region that is unsafe to overlap during
@@ -421,16 +424,15 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
/* No need to set mapping for initrd, it will be handled in VO. */
/* Avoid kernel command line. */
- cmd_line = (u64)boot_params->ext_cmd_line_ptr << 32;
- cmd_line |= boot_params->hdr.cmd_line_ptr;
+ cmd_line = get_cmd_line_ptr();
/* Calculate size of cmd_line. */
- ptr = (char *)(unsigned long)cmd_line;
- for (cmd_line_size = 0; ptr[cmd_line_size++];)
- ;
- 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,
- mem_avoid[MEM_AVOID_CMDLINE].size);
+ if (cmd_line) {
+ cmd_line_size = strlen((char *)cmd_line) + 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,
+ mem_avoid[MEM_AVOID_CMDLINE].size);
+ }
/* Avoid boot parameters. */
mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params;
|