Re: [PATCH v5 04/15] crypto: ti - Fix use-after-free of dev_data on DTHEv2 driver removal

[Herbert Xu <herbert@gondor.apana.org.au>]

On Fri, Sep 18, 2026 at 03:52:34PM +0530, T Pratham wrote:
> Each *_init_tfm() caches a pointer to the per-instance struct dthe_data
> in its transform context (ctx->dev_data), but never takes a reference on
> it. If there are tfms in progress when dthe_remove() is called, the devm
> allocated dev_data gets freed. Then ctx->dev_data will point to a memory
> that has been freed.
> 
> Move dthe_data to req_ctx structs of algorithms, and store the device
> pointer in tfm_ctx. Add a refcnt to struct dthe_data, which atomically
> counts the number of requests enqueued in the crypto engine queue which
> reference the dthe_data object.
> 
> A waitqueue waits on this atomic counter to get back to zero in
> dthe_remove() before doing the driver teardown.
> 
> Fixes: 52f641bc63a46 ("crypto: ti - Add driver for DTHE V2 AES Engine (ECB, CBC)")
> Signed-off-by: T Pratham <t-pratham@ti.com>
> ---
>  drivers/crypto/ti/dthev2-aes.c    | 74 +++++++++++++++++++++----------
>  drivers/crypto/ti/dthev2-common.c | 40 ++++++++++++++---
>  drivers/crypto/ti/dthev2-common.h | 52 ++++++++++++++++++++--
>  3 files changed, 134 insertions(+), 32 deletions(-)

Please check the Sashiko comments:

https://sashiko.dev/#/patchset/20260918102245.2784000-1-t-pratham%40ti.com

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt