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@xxxxxxxxxxxxxxx # 5.4 Cc: stable@xxxxxxxxxxxxxxx # 5.10 Reported-by: Nimish Mishra <neelam.nimish@xxxxxxxxx> Reported-by: Anirban Chakraborty <ch.anirban00727@xxxxxxxxx> Reported-by: Debdeep Mukhopadhyay <debdeep.mukhopadhyay@xxxxxxxxx> Suggested-by: Jerome Forissier <jerome.forissier@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> [JW: backport to stable 5.4 and 5.10 + update commit message] Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx> --- 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; + shm = tee_shm_register(ctx, data.addr, data.length, TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED); if (IS_ERR(shm)) -- 2.31.1