From: Mikulas Patocka Date: Thu, 16 Jun 2022 17:28:57 +0000 (-0400) Subject: dm mirror log: round up region bitmap size to BITS_PER_LONG X-Git-Tag: baikal/mips/sdk6.1~5478^2 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=f569a3ade581fb8ed0934becf0409d588103d19e;p=kernel.git dm mirror log: round up region bitmap size to BITS_PER_LONG The code in dm-log rounds up bitset_size to 32 bits. It then uses find_next_zero_bit_le on the allocated region. find_next_zero_bit_le accesses the bitmap using unsigned long pointers. So, on 64-bit architectures, it may access 4 bytes beyond the allocated size. Fix this bug by rounding up bitset_size to BITS_PER_LONG. This bug was found by running the lvm2 testsuite with kasan. Fixes: fccf92f72768 ("[PATCH] dm mirror log: bitset_size fix") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index 06f328928a7f5..2dda05aada231 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -415,8 +415,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, /* * Work out how many "unsigned long"s we need to hold the bitset. */ - bitset_size = dm_round_up(region_count, - sizeof(*lc->clean_bits) << BYTE_SHIFT); + bitset_size = dm_round_up(region_count, BITS_PER_LONG); bitset_size >>= BYTE_SHIFT; lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);