[U-Boot] [PATCH] ppc: ppmc7xx: Fix possible out-of-bound access

The flash_info_t->start[] field is limited in size by CONFIG_SYS_MAX_FLASH_SECT macro, which is set to 19 for this board in the board config file. If we inspect the board/ppmc7xx/flash.c closely, especially the flash_get_size() function, we can notice the "switch ((long)flashtest)" at around line 80 having a few results which will set flash_info_t->sector_count to value higher than 19, for example "case AMD_ID_LV640U" will set it to 128. Notice that right underneath, iteration over flash_info_t->start[] happens and the upper bound for the interation is flash_info_t->sector_count. Now if the sector_count is 128 as it is for the AMD_ID_LV640U case, but the CONFIG_SYS_MAX_FLASH_SECT limiting the start[] is only 19, an access past the start[] array much happen. Moreover, during this iteration, the field is written to, so memory corruption is inevitable.
Signed-off-by: Marek Vasut marex@denx.de Cc: Wolfgang Denk wd@denx.de Cc: Tom Rini trini@ti.com Cc: Richard Danter richard.danter@windriver.com --- include/configs/ppmc7xx.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/configs/ppmc7xx.h b/include/configs/ppmc7xx.h index 5cd6609..d4d7f9e 100644 --- a/include/configs/ppmc7xx.h +++ b/include/configs/ppmc7xx.h @@ -233,7 +233,7 @@ #define CONFIG_SYS_FLASH_ERASE_TOUT 250000 #define CONFIG_SYS_FLASH_WRITE_TOUT 5000 #define CONFIG_SYS_MAX_FLASH_BANKS 1 -#define CONFIG_SYS_MAX_FLASH_SECT 19 +#define CONFIG_SYS_MAX_FLASH_SECT 128
/*

Dear Marek Vasut,
In message 1369018900-11198-1-git-send-email-marex@denx.de you wrote:
The flash_info_t->start[] field is limited in size by CONFIG_SYS_MAX_FLASH_SECT macro, which is set to 19 for this board in the board config file. If we inspect the board/ppmc7xx/flash.c closely, especially the flash_get_size() function, we can notice the "switch ((long)flashtest)" at around line 80 having a few results which will set flash_info_t->sector_count to value higher than 19, for example "case AMD_ID_LV640U" will set it to 128. Notice that right underneath, iteration over flash_info_t->start[] happens and the upper bound for the interation is flash_info_t->sector_count. Now if the sector_count is 128 as it is for the AMD_ID_LV640U case, but the CONFIG_SYS_MAX_FLASH_SECT limiting the start[] is only 19, an access past the start[] array much happen. Moreover, during this iteration, the field is written to, so memory corruption is inevitable.
Signed-off-by: Marek Vasut marex@denx.de Cc: Wolfgang Denk wd@denx.de Cc: Tom Rini trini@ti.com Cc: Richard Danter richard.danter@windriver.com
include/configs/ppmc7xx.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Applied, thanks.
Best regards,
Wolfgang Denk
participants (2)
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Marek Vasut
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Wolfgang Denk