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: stable@vger.kernel.org Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru --- fs/f2fs/dir.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index cbd7a5e96a37..14900ca8a9ff 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -166,7 +166,8 @@ static unsigned long dir_block_index(unsigned int level, unsigned long bidx = 0;

for (i = 0; i < level; i++) - bidx += dir_buckets(i, dir_level) * bucket_blocks(i); + bidx += mul_u32_u32(dir_buckets(i, dir_level), + bucket_blocks(i)); bidx += idx * bucket_blocks(level); return bidx; }