On Mon, Aug 22, 2022 at 03:12:27PM +0200, Jens Wiklander 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]
You already sent me a 5.4 version here: https://lore.kernel.org/r/20220822092621.3691771-1-jens.wiklander@linaro.org
And I applied that.
And for 5.10, it's already in the tree as commit 578c349570d2 ("tee: add overflow check in register_shm_helper()") and was in the 5.10.137 release.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org
drivers/tee/tee_core.c | 3 +++ 1 file changed, 3 insertions(+)
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;
What I took in 5.10.137 was:
+ if (!access_ok((void __user *)addr, length)) + return ERR_PTR(-EFAULT);
Should I fix it up to look like what you sent here instead?
confused,
greg k-h