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| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-07-28 01:07:54 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-31 11:07:51 +0200 |
| commit | 709709ac6410f4a14ded158a4b23b979e33e10fb (patch) | |
| tree | f72d7d905e9d4390db05741ac6641e03e8dc3c37 /arch/x86/boot/compressed/kaslr.c | |
| parent | Linux 5.8-rc7 (diff) | |
| download | linux-709709ac6410f4a14ded158a4b23b979e33e10fb.tar.xz linux-709709ac6410f4a14ded158a4b23b979e33e10fb.zip | |
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@alum.mit.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200727230801.3468620-2-nivedita@alum.mit.edu
Diffstat (limited to 'arch/x86/boot/compressed/kaslr.c')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index d7408af55738..e0f69f3625ae 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; |