diff options
| author | Jens Wiklander <jens.wiklander@linaro.org> | 2022-08-18 13:08:59 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:15:48 +0200 |
| commit | b37e0f17653c00b586cdbcdf0dbca475358ecffd (patch) | |
| tree | 5d66e376ebf830305a5aef484b9c8446dc04b0bc | |
| parent | 2fc13fdacbf351e722b8e7ab1e0c2485db3466fb (diff) | |
tee: add overflow check in register_shm_helper()
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:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
Modules linked in:
CPU: 1 PID: 173 Comm: optee_example_a Not tainted 5.19.0 #11
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
pc : internal_get_user_pages_fast+0x474/0xa80
Call trace:
internal_get_user_pages_fast+0x474/0xa80
pin_user_pages_fast+0x24/0x4c
register_shm_helper+0x194/0x330
tee_shm_register_user_buf+0x78/0x120
tee_ioctl+0xd0/0x11a0
__arm64_sys_ioctl+0xa8/0xec
invoke_syscall+0x48/0x114
Fix this by adding an an explicit call to access_ok() in
tee_shm_register_user_buf() to catch an invalid user space address
early.
Fixes: 033ddf12bcf5 ("tee: add register user memory")
Cc: stable@vger.kernel.org
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: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[JW: backport to stable-4.19 + update commit message]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tee/tee_core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index d42fc2ae8592..e568cb4b2ffc 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -175,6 +175,10 @@ tee_ioctl_shm_register(struct tee_context *ctx, if (data.flags) return -EINVAL; + if (!access_ok(VERIFY_WRITE, (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)) |