f2fs: prevent possible int overflow in dir_block_index()

The result of multiplication between values derived from functions
dir_buckets() and bucket_blocks() *could* technically reach
2^30 * 2^2 = 2^32.

While unlikely to happen, it is prudent to ensure that it will not
lead to integer overflow. Thus, use mul_u32_u32() as it's more
appropriate to mitigate the issue.

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 3843154598a0 ("f2fs: introduce large directory support")
Cc: [email protected]
Signed-off-by: Nikita Zhandarovich <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

0 files changed, 0 insertions, 0 deletions