diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2025-11-18 11:10:26 +0900 |
|---|---|---|
| committer | Namjae Jeon <linkinjeon@kernel.org> | 2025-12-03 10:00:16 +0900 |
| commit | d70a5804c563b5e34825353ba9927509df709651 (patch) | |
| tree | e02ec3750cb135b8575491e8f56787d59cca06fd /fs | |
| parent | 866cba3675416c6cf446acb25d7c700eead1420e (diff) | |
exfat: fix divide-by-zero in exfat_allocate_bitmap
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: 9fd688678dd8 ("exfat: optimize allocation bitmap loading time")
Reported-by: Jiaming Zhang <r772577952@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exfat/balloc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index b387bf7df65e..5429041c7eaf 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -106,7 +106,7 @@ static int exfat_allocate_bitmap(struct super_block *sb, (PAGE_SHIFT - sb->s_blocksize_bits); for (i = 0; i < sbi->map_sectors; i++) { /* Trigger the next readahead in advance. */ - if (0 == (i % max_ra_count)) { + if (max_ra_count && 0 == (i % max_ra_count)) { blk_start_plug(&plug); for (j = i; j < min(max_ra_count, sbi->map_sectors - i) + i; j++) sb_breadahead(sb, sector + j); |