• Kees Cook's avatar
    spi: dw: Avoid stack content exposure · 386f771a
    Kees Cook authored
    Since "data" is u32, &data is a "u32 *" type, which means pointer math
    will move in u32-sized steps. This was meant to be a byte offset, so
    cast &data to "char *" to aim the copy into the correct location.
    
    Seen with -Warray-bounds (and found by Coverity):
    
    In file included from ./include/linux/string.h:269,
                     from ./arch/powerpc/include/asm/paca.h:15,
                     from ./arch/powerpc/include/asm/current.h:13,
                     from ./include/linux/mutex.h:14,
                     from ./include/linux/notifier.h:14,
                     from ./include/linux/clk.h:14,
                     from drivers/spi/spi-dw-bt1.c:12:
    In function 'memcpy',
        inlined from 'dw_spi_bt1_dirmap_copy_from_map' at drivers/spi/spi-dw-bt1.c:87:3:
    ./include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset 4 is out of the bounds [0, 4] of object 'data' with type 'u32' {aka 'unsigned int'} [-Warray-bounds]
       20 | #define __underlying_memcpy __builtin_memcpy
          |    ...
    386f771a
spi-dw-bt1.c 8.56 KB