On Fri, Feb 07, 2020 at 07:26:32PM -0500, Steven Rostedt wrote: > > 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> Cool; thanks for fixing this! Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees > --- > 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 > -- Kees Cook
