[ Upstream commit d70a5804c5 ]
The variable max_ra_count can be 0 in exfat_allocate_bitmap(),
which causes a divide-by-zero error in the subsequent modulo operation
(i % max_ra_count), leading to a system crash.
When max_ra_count is 0, it means that readahead is not used. This patch
load the bitmap without readahead.
Fixes: 9fd688678d ("exfat: optimize allocation bitmap loading time")
Reported-by: Jiaming Zhang <r772577952@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
88fc3dd6e6