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authorDave Jones <davej@redhat.com>2012-04-12 16:03:56 -0400
committerChris Mason <chris.mason@oracle.com>2012-04-12 16:03:56 -0400
commit4edc2ca388d62abffe38149f6ac00e749ea721c5 (patch)
tree6e31a2d72b9bb05f46960c0a8a789044f5dcf584
parente627ee7bcd42b4e3a03ca01a8e46dcb4033c5ae0 (diff)
Btrfs: fix use-after-free in __btrfs_end_transaction
49b25e0540904be0bf558b84475c69d72e4de66e introduced a use-after-free bug that caused spurious -EIO's to be returned. Do the check before we free the transaction. Cc: David Sterba <dsterba@suse.cz> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/transaction.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8da29e8e4de..11b77a59db6 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -480,6 +480,7 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_fs_info *info = root->fs_info;
int count = 0;
+ int err = 0;
if (--trans->use_count) {
trans->block_rsv = trans->orig_rsv;
@@ -532,18 +533,18 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
if (current->journal_info == trans)
current->journal_info = NULL;
- memset(trans, 0, sizeof(*trans));
- kmem_cache_free(btrfs_trans_handle_cachep, trans);
if (throttle)
btrfs_run_delayed_iputs(root);
if (trans->aborted ||
root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
- return -EIO;
+ err = -EIO;
}
- return 0;
+ memset(trans, 0, sizeof(*trans));
+ kmem_cache_free(btrfs_trans_handle_cachep, trans);
+ return err;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,