From: Wenwen Wang <wenwen@xxxxxxxxxx>
commit f311ade3a7adf31658ed882aaab9f9879fdccef7 upstream.
In btrfs_ref_tree_mod(), 'ref' and 'ra' are allocated through kzalloc() and
kmalloc(), respectively. In the following code, if an error occurs, the
execution will be redirected to 'out' or 'out_unlock' and the function will
be exited. However, on some of the paths, 'ref' and 'ra' are not
deallocated, leading to memory leaks. For example, if 'action' is
BTRFS_ADD_DELAYED_EXTENT, add_block_entry() will be invoked. If the return
value indicates an error, the execution will be redirected to 'out'. But,
'ref' is not deallocated on this path, causing a memory leak.
To fix the above issues, deallocate both 'ref' and 'ra' before exiting from
the function when an error is encountered.
CC: stable@xxxxxxxxxxxxxxx # 4.15+
Signed-off-by: Wenwen Wang <wenwen@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/ref-verify.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -747,6 +747,7 @@ int btrfs_ref_tree_mod(struct btrfs_root
*/
be = add_block_entry(root->fs_info, bytenr, num_bytes, ref_root);
if (IS_ERR(be)) {
+ kfree(ref);
kfree(ra);
ret = PTR_ERR(be);
goto out;
@@ -760,6 +761,8 @@ int btrfs_ref_tree_mod(struct btrfs_root
"re-allocated a block that still has references to it!");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
+ kfree(ref);
+ kfree(ra);
goto out_unlock;
}
@@ -822,6 +825,7 @@ int btrfs_ref_tree_mod(struct btrfs_root
"dropping a ref for a existing root that doesn't have a ref on the block");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
+ kfree(ref);
kfree(ra);
goto out_unlock;
}
@@ -837,6 +841,7 @@ int btrfs_ref_tree_mod(struct btrfs_root
"attempting to add another ref for an existing ref on a tree block");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
+ kfree(ref);
kfree(ra);
goto out_unlock;
}
