From: Arvind Sankar <nivedita@xxxxxxxxxxxx> commit 8a8a3237a78cbc0557f0eb16a89f16d616323e99 upstream. Make the command line parsing more robust, by handling the case it is not NUL-terminated. Use strnlen instead of strlen, and make sure that the temporary copy is NUL-terminated before parsing. Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200813185811.554051-4-nivedita@xxxxxxxxxxxx Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/firmware/efi/libstub/efi-stub-helper.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -194,12 +194,14 @@ efi_status_t efi_parse_options(char cons if (!cmdline) return EFI_SUCCESS; - len = strlen(cmdline) + 1; + len = strnlen(cmdline, COMMAND_LINE_SIZE - 1) + 1; status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, len, (void **)&buf); if (status != EFI_SUCCESS) return status; - str = skip_spaces(memcpy(buf, cmdline, len)); + memcpy(buf, cmdline, len - 1); + buf[len - 1] = '\0'; + str = skip_spaces(buf); while (*str) { char *param, *val;
