From 60d7d5a63189c9f77a190c9965861dc15482c2d0 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Fri, 22 Mar 2013 11:26:21 +0000 Subject: env: fix potential stack overflow in environment functions Most of the various environment functions create CONFIG_ENV_SIZE buffers on the stack. At least on ARM and PPC which have 4KB stacks, this can overflow the stack if we have large environment sizes. So move all the buffers off the stack to static buffers. Signed-off-by: Rob Herring --- common/env_dataflash.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'common/env_dataflash.c') diff --git a/common/env_dataflash.c b/common/env_dataflash.c index 38c9615..0591b99 100644 --- a/common/env_dataflash.c +++ b/common/env_dataflash.c @@ -30,6 +30,7 @@ DECLARE_GLOBAL_DATA_PTR; env_t *env_ptr; char *env_name_spec = "dataflash"; +static char env_buf[CONFIG_ENV_SIZE]; uchar env_get_char_spec(int index) { @@ -42,11 +43,9 @@ uchar env_get_char_spec(int index) void env_relocate_spec(void) { - char buf[CONFIG_ENV_SIZE]; + read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, env_buf); - read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf); - - env_import(buf, 1); + env_import(env_buf, 1); } #ifdef CONFIG_ENV_OFFSET_REDUND @@ -55,20 +54,20 @@ void env_relocate_spec(void) int saveenv(void) { - env_t env_new; + env_t *env_new = (env_t *)env_buf; ssize_t len; char *res; - res = (char *)&env_new.data; + res = (char *)env_new->data; len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL); if (len < 0) { error("Cannot export environment: errno = %d\n", errno); return 1; } - env_new.crc = crc32(0, env_new.data, ENV_SIZE); + env_new->crc = crc32(0, env_new->data, ENV_SIZE); return write_dataflash(CONFIG_ENV_ADDR, - (unsigned long)&env_new, + (unsigned long)env_new, CONFIG_ENV_SIZE); } -- cgit v1.1