On Sun Jun 9, 2024 at 12:29 PM EEST, Joe Hattori wrote:
> In tpm_bios_measurements_open(), get_device() is called on the device
> embedded in struct tpm_chip. In the error path, however, put_device() is
> not called. This could result in a reference count leak, which could
When it does not then?
> prevent the device from being properly released. This commit makes sure
> to call put_device() when the tpm_bios_measurements_open() fails.
s/could//g
Either *is* or *is not*.
>
> Signed-off-by: Joe Hattori <joe@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/char/tpm/eventlog/common.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
> index 639c3f395a5a..df213ec428ca 100644
> --- a/drivers/char/tpm/eventlog/common.c
> +++ b/drivers/char/tpm/eventlog/common.c
> @@ -44,11 +44,13 @@ static int tpm_bios_measurements_open(struct inode *inode,
>
> /* now register seq file */
> err = seq_open(file, seqops);
> - if (!err) {
> - seq = file->private_data;
> - seq->private = chip;
> + if (err) {
> + put_device(&chip->dev);
> + return err;
> }
>
> + seq = file->private_data;
> + seq->private = chip;
So this does two things:
1. It restructures code.
2. Possibly fixes a leak (with quick skimo does).
So it breaks "Separate your changes" section of [1].
Instead:
if (!err) {
seq = file->private_data;
seq->private = chip;
} else {
put_device(&chip->dev);
}
I.e. least likelyhood of merge conflicts, when backporting.
Also, add a fixes tag (also [1]).
[1] https://docs.kernel.org/process/submitting-patches.html
BR, Jarkko
