Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Two more bug fixes (including a regression) for 5.6"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: potential crash on allocation error in ext4_alloc_flex_bg_array()
jbd2: fix data races at struct journal_head
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ff1b764..0c7c4ad 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2391,7 +2391,7 @@
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct flex_groups **old_groups, **new_groups;
- int size, i;
+ int size, i, j;
if (!sbi->s_log_groups_per_flex)
return 0;
@@ -2412,8 +2412,8 @@
sizeof(struct flex_groups)),
GFP_KERNEL);
if (!new_groups[i]) {
- for (i--; i >= sbi->s_flex_groups_allocated; i--)
- kvfree(new_groups[i]);
+ for (j = sbi->s_flex_groups_allocated; j < i; j++)
+ kvfree(new_groups[j]);
kvfree(new_groups);
ext4_msg(sb, KERN_ERR,
"not enough memory for %d flex groups", size);
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index d181948..3dccc23 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1150,8 +1150,8 @@
/* For undo access buffer must have data copied */
if (undo && !jh->b_committed_data)
goto out;
- if (jh->b_transaction != handle->h_transaction &&
- jh->b_next_transaction != handle->h_transaction)
+ if (READ_ONCE(jh->b_transaction) != handle->h_transaction &&
+ READ_ONCE(jh->b_next_transaction) != handle->h_transaction)
goto out;
/*
* There are two reasons for the barrier here:
@@ -2569,8 +2569,8 @@
* our jh reference and thus __jbd2_journal_file_buffer() must not
* take a new one.
*/
- jh->b_transaction = jh->b_next_transaction;
- jh->b_next_transaction = NULL;
+ WRITE_ONCE(jh->b_transaction, jh->b_next_transaction);
+ WRITE_ONCE(jh->b_next_transaction, NULL);
if (buffer_freed(bh))
jlist = BJ_Forget;
else if (jh->b_modified)
