5.15-stable review patch. If anyone has any objections, please let me know.
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From: Bragatheswaran Manickavel bragathemanick0908@gmail.com
commit f91192cd68591c6b037da345bc9fcd5e50540358 upstream.
In btrfs_ref_tree_mod(), when !parent 're' was allocated through kmalloc(). 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, 're' are not deallocated and may lead to memory leaks.
For example: lookup_block_entry() for 'be' returns NULL, the out label will be invoked. During that flow ref and 'ra' are freed but not 're', which can potentially lead to a memory leak.
CC: stable@vger.kernel.org # 5.10+ Reported-and-tested-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f Signed-off-by: Bragatheswaran Manickavel bragathemanick0908@gmail.com 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 | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/btrfs/ref-verify.c +++ b/fs/btrfs/ref-verify.c @@ -788,6 +788,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i dump_ref_action(fs_info, ra); kfree(ref); kfree(ra); + kfree(re); goto out_unlock; } else if (be->num_refs == 0) { btrfs_err(fs_info, @@ -797,6 +798,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i dump_ref_action(fs_info, ra); kfree(ref); kfree(ra); + kfree(re); goto out_unlock; }