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authorJan Kara <jack@suse.cz>2019-04-06 18:33:06 -0400
committerTheodore Ts'o <tytso@mit.edu>2019-04-06 18:33:06 -0400
commit31562b954b60f02acb91b7349dc6432d3f8c3c5f (patch)
tree765666fd6d389929f1b6c7da4593d0b064562414 /fs/ext4
parentfb203751099eecf145317685ee480a51e5b246de (diff)
ext4: make sanity check in mballoc more strict
The sanity check in mb_find_extent() only checked that returned extent does not extend past blocksize * 8, however it should not extend past EXT4_CLUSTERS_PER_GROUP(sb). This can happen when clusters_per_group < blocksize * 8 and the tail of the bitmap is not properly filled by 1s which happened e.g. when ancient kernels have grown the filesystem. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/mballoc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 6fb76d408093..8ef5f12bbee2 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1539,7 +1539,7 @@ static int mb_find_extent(struct ext4_buddy *e4b, int block,
ex->fe_len += 1 << order;
}
- if (ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))) {
+ if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
/* Should never happen! (but apparently sometimes does?!?) */
WARN_ON(1);
ext4_error(e4b->bd_sb, "corruption or bug in mb_find_extent "