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| author | Jens Wiklander <jens.wiklander@linaro.org> | 2022-08-18 14:08:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-21 16:16:26 +0300 |
| commit | 578c349570d2a912401963783b36e0ec7a25c053 (patch) | |
| tree | a9076b6d7a645a26af1f1282b2712205840975d2 /drivers | |
| parent | 98b20e1612e69bf91185cf722a96293a136fe894 (diff) | |
| download | linux-578c349570d2a912401963783b36e0ec7a25c053.tar.xz | |
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tee/tee_shm.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 499fccba3d74..6e662fb131d5 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -222,6 +222,9 @@ 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); |