Hi Greg,
On Mon, 22 Aug 2022 at 18:42, Jens Wiklander jens.wiklander@linaro.org wrote:
commit 573ae4f13f630d6660008f1974c0a8a29c30e18a upstream.
With special lengths supplied by user space, tee_shm_register() has an integer overflow when calculating the number of pages covered by a supplied user space memory region.
This may cause pin_user_pages_fast() to do a NULL pointer dereference.
Fix this by adding an an explicit call to access_ok() in tee_ioctl_shm_register() to catch an invalid user space address early.
Fixes: 033ddf12bcf5 ("tee: add register user memory") Cc: stable@vger.kernel.org # 5.4 Cc: stable@vger.kernel.org # 5.10 Reported-by: Nimish Mishra neelam.nimish@gmail.com Reported-by: Anirban Chakraborty ch.anirban00727@gmail.com Reported-by: Debdeep Mukhopadhyay debdeep.mukhopadhyay@gmail.com Suggested-by: Jerome Forissier jerome.forissier@linaro.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org [JW: backport to stable 5.4 and 5.10 + update commit message] Signed-off-by: Jens Wiklander jens.wiklander@linaro.org
drivers/tee/tee_core.c | 3 +++ 1 file changed, 3 insertions(+)
The v5.15 backport [1] for this fix has broken the kernel consumers for tee_shm_register(), the trusted keys driver is one of them reported here [2]. We need to fix that up with the following change [3]. Would you like to revert the backport and apply the correct one or should I prepare a fix patch for the following [3]?
[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=l...
[2] https://github.com/OP-TEE/optee_os/issues/5624
[3]
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 3fc426dad2df..d5c4fcd8733d 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -334,6 +334,9 @@ tee_ioctl_shm_register(struct tee_context *ctx, if (data.flags) return -EINVAL;
+ if (!access_ok((void __user *)data.addr, data.length)) + return ERR_PTR(-EFAULT); + shm = tee_shm_register(ctx, data.addr, data.length, TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED); if (IS_ERR(shm)) diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index bd96ebb82c8e..6fb4400333fb 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -223,9 +223,6 @@ 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); - mutex_lock(&teedev->mutex); shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); mutex_unlock(&teedev->mutex);
-Sumit
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index a7ccd4d2bd10..2db144d2d26f 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -182,6 +182,9 @@ tee_ioctl_shm_register(struct tee_context *ctx, if (data.flags) return -EINVAL;
if (!access_ok((void __user *)(unsigned long)data.addr, data.length))return -EFAULT;shm = tee_shm_register(ctx, data.addr, data.length, TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED); if (IS_ERR(shm))-- 2.31.1