Re: [PATCH v2 0/4] tpm: some tpm small fixes.

From: Jarkko Sakkinen

Date: Thu Oct 08 2026 - 13:52:53 EST


On Thu, Oct 08, 2026 at 09:16:19AM +0800, Pei Xiao wrote:
> This series fixes several small issues found during a code review of
> drivers/char/tpm:
>
> 1. tpm_ppi: tpm_show_ppi_response() stores its return value in an
> acpi_status (a u32 typedef), so error codes such as -EINVAL reach
> user space as huge positive values. Declare the variable as
> ssize_t to match the show callback's return type.
>
> 2. tpm_nsc: tpm_nsc_remove() doubles as the release callback of the
> hand-created platform device and dereferences the chip drvdata
> unconditionally; init failures before tpmm_chip_alloc() crash
> module load. Return early when the chip has not been created.
>
> 3. tpm_nsc: the cleanup runs twice on module exit because
> tpm_nsc_remove() is both the explicit cleanup and the device
> release callback; the second run operates on an already freed
> chip. Stop overriding the release callback, which also stops the
> platform object allocation from leaking.
>
> 4. tpm_dev: a zero-length read() discards a pending response,
> breaking the command/response pairing of the TPM character
> devices, although POSIX requires zero-count reads to have no side
> effects. Return early on a zero count.
>
> chhanges in v2:
> 1.add reviewed-by tag
> 2.remove patch 5:
> make the tpm_init() error messages consistently prefixed with "tpm: " and
> report the actual failure of tpm_dev_common_init().
> 3.modify patch 1 git commit information.
>
> Pei Xiao (4):
> tpm: tpm_ppi: fix zero-extension of negative error codes
> tpm: tpm_nsc: fix NULL pointer dereference on init failure
> tpm: tpm_nsc: stop using the cleanup callback as dev.release
> tpm: fix zero-length read discarding the pending response
>
> drivers/char/tpm/tpm-dev-common.c | 3 +++
> drivers/char/tpm/tpm_nsc.c | 8 ++++++--
> drivers/char/tpm/tpm_ppi.c | 2 +-
> 3 files changed, 10 insertions(+), 3 deletions(-)
>
> --
> 2.25.1
>

Right, so I've already applied some of the patches so I'm a bit
confused what to do with this.

See:

https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/log/

Is there something wrong in the ones that I already applied?

Br, Jarkko