Re: FAILED: patch "[PATCH] tpm: Fix auth session leak in tpm2_get_random() error path" failed to apply to 7.2-stable tree

[Jarkko Sakkinen <jarkko@kernel.org>]

On Sat, Oct 03, 2026 at 03:20:16PM +0200, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 7.2-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.2.y
> git checkout FETCH_HEAD
> git cherry-pick -x 1e2f9a611b334ce6ed1dc4a9e1587c7a11d2be30
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026100316-exclusion-mustang-f624@gregkh' --subject-prefix 'PATCH 7.2.y' 'HEAD^..'

I backported the other failing patch to stable kernels but this is
clearly my bad i.e. it does not need stable backport at all.

Sorry, can be safely ignored.

> 
> Possible dependencies:
> 
> 
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From 1e2f9a611b334ce6ed1dc4a9e1587c7a11d2be30 Mon Sep 17 00:00:00 2001
> From: Jiangshan Yi <yijiangshan@kylinos.cn>
> Date: Wed, 2 Sep 2026 15:48:39 +0800
> Subject: [PATCH] tpm: Fix auth session leak in tpm2_get_random() error path
> 
> When tpm_buf_fill_hmac_session() fails in tpm2_get_random(), the error
> path returns without calling tpm2_end_auth_session(), leaking the auth
> session. All other error paths in the function handle this correctly.
> 
> Fixes: 3d9e043dab0a ("tpm-buf: Memory-safe allocations")
> Cc: stable@vger.kernel.orga # v6.12+
> Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
> Link: https://lore.kernel.org/r/20260902074839.417419-1-yijiangshan@kylinos.cn
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> 
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 48cec39995fe..96e0e06bbbf0 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -281,8 +281,10 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
>  		}
>  		tpm_buf_append_u16(buf, num_bytes);
>  		err = tpm_buf_fill_hmac_session(chip, buf);
> -		if (err)
> +		if (err) {
> +			tpm2_end_auth_session(chip);
>  			return err;
> +		}
>  
>  		err = tpm_transmit_cmd(chip, buf,
>  				       offsetof(struct tpm2_get_random_out,
> 


Br, Jarkko