From: Masami Hiramatsu mhiramat@kernel.org

If there is a bootconfig data in the tail of initrd/initramfs, initrd image sanity check caused an error while decompression stage as follows.

[ 0.883882] Unpacking initramfs... [ 2.696429] Initramfs unpacking failed: invalid magic at start of compressed archive

This error will be ignored if CONFIG_BLK_DEV_RAM=n, but CONFIG_BLK_DEV_RAM=y the kernel failed to mount rootfs and causes a panic.

To fix this issue, shrink down the initrd_end for removing tailing bootconfig data while boot the kernel.

Link: http://lkml.kernel.org/r/158788401014.24243.17424755854115077915.stgit@devno...

Cc: Borislav Petkov bp@alien8.de Cc: Kees Cook keescook@chromium.org Cc: Ingo Molnar mingo@kernel.org Cc: Andrew Morton akpm@linux-foundation.org Cc: stable@vger.kernel.org Fixes: 7684b8582c24 ("bootconfig: Load boot config from the tail of initrd") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- init/main.c | 69 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 52 insertions(+), 17 deletions(-)

diff --git a/init/main.c b/init/main.c index a48617f2e5e5..1a5da2c2660c 100644 --- a/init/main.c +++ b/init/main.c @@ -257,6 +257,47 @@ static int __init loglevel(char *str)

early_param("loglevel", loglevel);

+#ifdef CONFIG_BLK_DEV_INITRD +static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +{ + u32 size, csum; + char *data; + u32 *hdr; + + if (!initrd_end) + return NULL; + + data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; + if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) + return NULL; + + hdr = (u32 *)(data - 8); + size = hdr[0]; + csum = hdr[1]; + + data = ((void *)hdr) - size; + if ((unsigned long)data < initrd_start) { + pr_err("bootconfig size %d is greater than initrd size %ld\n", + size, initrd_end - initrd_start); + return NULL; + } + + /* Remove bootconfig from initramfs/initrd */ + initrd_end = (unsigned long)data; + if (_size) + *_size = size; + if (_csum) + *_csum = csum; + + return data; +} +#else +static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +{ + return NULL; +} +#endif + #ifdef CONFIG_BOOT_CONFIG

char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; @@ -357,9 +398,12 @@ static void __init setup_boot_config(const char *cmdline) int pos; u32 size, csum; char *data, *copy; - u32 *hdr; int ret;

+ data = get_boot_config_from_initrd(&size, &csum); + if (!data) + goto not_found; + strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, bootconfig_params); @@ -367,27 +411,12 @@ static void __init setup_boot_config(const char *cmdline) if (!bootconfig_found) return;

- if (!initrd_end) - goto not_found; - - data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; - if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) - goto not_found; - - hdr = (u32 *)(data - 8); - size = hdr[0]; - csum = hdr[1]; - if (size >= XBC_DATA_MAX) { pr_err("bootconfig size %d greater than max size %d\n", size, XBC_DATA_MAX); return; }

- data = ((void *)hdr) - size; - if ((unsigned long)data < initrd_start) - goto not_found; - if (boot_config_checksum((unsigned char *)data, size) != csum) { pr_err("bootconfig checksum failed\n"); return; @@ -420,8 +449,14 @@ static void __init setup_boot_config(const char *cmdline) not_found: pr_err("'bootconfig' found on command line, but no bootconfig found\n"); } + #else -#define setup_boot_config(cmdline) do { } while (0) + +static void __init setup_boot_config(const char *cmdline) +{ + /* Remove bootconfig data from initrd */ + get_boot_config_from_initrd(NULL, NULL); +}

static int __init warn_bootconfig(char *str) {