Hi,
On Mon, Aug 22, 2022 at 1:15 PM Pavel Machek pavel@denx.de wrote:
Hi!
From: Jens Wiklander jens.wiklander@linaro.org
commit 573ae4f13f630d6660008f1974c0a8a29c30e18a upstream.
With special lengths supplied by user space, register_shm_helper() has an integer overflow when calculating the number of pages covered by a supplied user space memory region.
This causes internal_get_user_pages_fast() a helper function of pin_user_pages_fast() to do a NULL pointer dereference:
Maybe this needs fixing, but this fix adds a memory leak or two. Note the goto err, that needs to be done.
Thanks for bringing this up. I believe the best option is to take the backport I just did for 5.4, it should apply cleanly on the 5.10 stable kernel too.
Greg, can you cherry-pick the 5.4 backport patch, or would you rather have an explicit backport for this stable kernel?
Cheers, Jens
Best regards, Pavel
Signed-off-by: Pavel Machek pavel@denx.de
+++ b/drivers/tee/tee_shm.c @@ -222,6 +222,9 @@ struct tee_shm *tee_shm_register(struct goto err; }
if (!access_ok((void __user *)addr, length))return ERR_PTR(-EFAULT);mutex_lock(&teedev->mutex); shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); mutex_unlock(&teedev->mutex);diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 6e662fb131d5..283fa50676a2 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -222,8 +222,10 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, goto err; }
if (!access_ok((void __user *)addr, length))return ERR_PTR(-EFAULT);
if (!access_ok((void __user *)addr, length)) {ret = ERR_PTR(-EFAULT);goto err;} mutex_lock(&teedev->mutex); shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);-- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany