Fixed bootloaders accepting flash writes to the bootloader region (thanks to NicoHood).

[pub/USBasp.git] / Bootloaders / MassStorage / BootloaderAPI.c

diff --git a/Bootloaders/MassStorage/BootloaderAPI.c b/Bootloaders/MassStorage/BootloaderAPI.c
index 5e8083e..c1e76d3 100644 (file)
--- a/Bootloaders/MassStorage/BootloaderAPI.c
+++ b/Bootloaders/MassStorage/BootloaderAPI.c
@@ -35,8 +35,20 @@
 
 #include "BootloaderAPI.h"
 
+static bool IsPageAddressValid(const uint32_t Address)
+{
+       /* Determine if the given page address is correctly aligned to the
+          start of a flash page. */
+       bool PageAddressIsAligned = !(Address & (SPM_PAGESIZE - 1));
+
+       return (Address < BOOT_START_ADDR) && PageAddressIsAligned;
+}
+
 void BootloaderAPI_ErasePage(const uint32_t Address)
 {
+       if (! IsPageAddressValid(Address))
+               return;
+
        ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
        {
                boot_page_erase_safe(Address);
@@ -47,6 +59,9 @@ void BootloaderAPI_ErasePage(const uint32_t Address)
 
 void BootloaderAPI_WritePage(const uint32_t Address)
 {
+       if (! IsPageAddressValid(Address))
+               return;
+
        ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
        {
                boot_page_write_safe(Address);