From: Wenwen Wang wenwen@cs.uga.edu
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@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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/ref-verify.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/fs/btrfs/ref-verify.c +++ b/fs/btrfs/ref-verify.c @@ -744,6 +744,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i */ 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_i "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_i "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_i "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; }