2011/4/3 Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>:
find_next bitops on m68k (find_next_zero_bit, find_next_bit, and
find_next_bit_le) may cause out of bounds memory access
when the bitmap size in bits % 32 != 0 and offset (the bitnumber
to start searching at) is very close to the bitmap size.
For example,
unsigned long bitmap[2] = { 0, 0 };
find_next_bit(bitmap, 63, 62);
1. find_next_bit() tries to find any set bits in bitmap[1],
but no bits set.
2. Then find_first_bit(bimap + 2, -1)
3. Unfortunately find_first_bit() takes unsigned int as the size argument.
4. find_first_bit will access bitmap[2~] until it find any set bits.
Add missing tests for stepping beyond the end of the bitmap to all
find_{first,next}_*() functions, and make sure they never return a value
larger than the bitmap size.
Reported-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Andreas Schwab <schwab@xxxxxxxxxxxxxx>
These patches look good.
I checked that find_next_zero_bit_le() and find_next_bit_le() work
as I expect.
--
To unsubscribe from this list: send the line "unsubscribe linux-m68k" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
