btrfs: ref-verify: fix memory leaks (f311ade3) · Commits · 戴 / test

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@vger.kernel.org # 4.15+ Signed-off-by:

Wenwen Wang <wenwen@cs.uga.edu> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/ref-verify.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -744,6 +744,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
		*/
		be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
		if (IS_ERR(be)) {
		kfree(ref);
		kfree(ra);
		ret = PTR_ERR(be);
		goto out;
		@@ -757,6 +758,8 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
		"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;
		}

		@@ -819,6 +822,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
		"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;
		}
		@@ -834,6 +838,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
		"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;
		}

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