From: Dmitry Monakhov dmonakhov@gmail.com
mainline inclusion from mainline-v5.7 commit eb5760863fc28feab28b567ddcda7e667e638da0 category: bugfix bugzilla: 34293 CVE: NA ---------------------------
We already has similar code in ext4_mb_complex_scan_group(), but ext4_mb_simple_scan_group() still affected.
Other reports: https://www.spinics.net/lists/linux-ext4/msg60231.html
Reviewed-by: Andreas Dilger adilger@dilger.ca Signed-off-by: Dmitry Monakhov dmonakhov@gmail.com Link: https://lore.kernel.org/r/20200310150156.641-1-dmonakhov@gmail.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/ext4/mballoc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5de20e6..392aa10 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1901,8 +1901,15 @@ void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, BUG_ON(buddy == NULL);
k = mb_find_next_zero_bit(buddy, max, 0); - BUG_ON(k >= max); - + if (k >= max) { + ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0, + "%d free clusters of order %d. But found 0", + grp->bb_counters[i], i); + ext4_mark_group_bitmap_corrupted(ac->ac_sb, + e4b->bd_group, + EXT4_GROUP_INFO_BBITMAP_CORRUPT); + break; + } ac->ac_found++;
ac->ac_b_ex.fe_len = 1 << i;