From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx> The current implementation does a naive search of "bootconfig" on the kernel command line. But this could find "bootconfig" that is part of another option in quotes (although highly unlikely). But it also needs to find '--' on the kernel command line to know if it should append a '--' or not when a bootconfig in the initrd file has an "init" section. The check uses the naive strstr() to find to see if it exists. But this can return a false positive if it exists in an option and then the "init" section in the initrd will not be appended properly. Using parse_args() to find both of these will solve both of these problems. Link: https://lore.kernel.org/r/202002070954.C18E7F58B@keescook Fixes: 7495e0926fdf3 ("bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline") Fixes: 1319916209ce8 ("bootconfig: init: Allow admin to use bootconfig for init command line") Reported-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> --- init/main.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) diff --git a/init/main.c b/init/main.c index 491f1cdb3105..e7261f1a3523 100644 --- a/init/main.c +++ b/init/main.c @@ -142,6 +142,15 @@ static char *extra_command_line; /* Extra init arguments */ static char *extra_init_args; +#ifdef CONFIG_BOOT_CONFIG +/* Is bootconfig on command line? */ +static bool bootconfig_found; +static bool initargs_found; +#else +# define bootconfig_found false +# define initargs_found false +#endif + static char *execute_command; static char *ramdisk_execute_command; @@ -336,17 +345,31 @@ u32 boot_config_checksum(unsigned char *p, u32 size) return ret; } +static int __init bootconfig_params(char *param, char *val, + const char *unused, void *arg) +{ + if (strcmp(param, "bootconfig") == 0) { + bootconfig_found = true; + } else if (strcmp(param, "--") == 0) { + initargs_found = true; + } + return 0; +} + static void __init setup_boot_config(const char *cmdline) { + static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; u32 size, csum; char *data, *copy; const char *p; u32 *hdr; int ret; - p = strstr(cmdline, "bootconfig"); - if (!p || (p != cmdline && !isspace(*(p-1))) || - (p[10] && !isspace(p[10]))) + strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); + parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, + bootconfig_params); + + if (!bootconfig_found) return; if (!initrd_end) @@ -563,11 +586,12 @@ static void __init setup_command_line(char *command_line) * to init. */ len = strlen(saved_command_line); - if (!strstr(boot_command_line, " -- ")) { + if (initargs_found) { + saved_command_line[len++] = ' '; + } else { strcpy(saved_command_line + len, " -- "); len += 4; - } else - saved_command_line[len++] = ' '; + } strcpy(saved_command_line + len, extra_init_args); } -- 2.20.1
