diff options
| author | Jens Wiklander <jens.wiklander@linaro.org> | 2025-09-19 10:48:31 +0200 |
|---|---|---|
| committer | Jens Wiklander <jens.wiklander@linaro.org> | 2025-09-22 08:47:00 +0200 |
| commit | d5cf5b37064b1699d946e8b7ab4ac7d7d101814c (patch) | |
| tree | b2628fc0c79ab5afda06485f14f6e60d43935837 | |
| parent | 8f5ae30d69d7543eee0d70083daf4de8fe15d585 (diff) | |
tee: fix register_shm_helper()
In register_shm_helper(), fix incorrect error handling for a call to
iov_iter_extract_pages(). A case is missing for when
iov_iter_extract_pages() only got some pages and return a number larger
than 0, but not the requested amount.
This fixes a possible NULL pointer dereference following a bad input from
ioctl(TEE_IOC_SHM_REGISTER) where parts of the buffer isn't mapped.
Cc: stable@vger.kernel.org
Reported-by: Masami Ichikawa <masami256@gmail.com>
Closes: https://lore.kernel.org/op-tee/CACOXgS-Bo2W72Nj1_44c7bntyNYOavnTjJAvUbEiQfq=u9W+-g@mail.gmail.com/
Tested-by: Masami Ichikawa <masami256@gmail.com>
Fixes: 7bdee4157591 ("tee: Use iov_iter to better support shared buffer registration")
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
| -rw-r--r-- | drivers/tee/tee_shm.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index daf6e5cfd59a..76c54e1dc98c 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -319,6 +319,14 @@ register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags, if (unlikely(len <= 0)) { ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM); goto err_free_shm_pages; + } else if (DIV_ROUND_UP(len + off, PAGE_SIZE) != num_pages) { + /* + * If we only got a few pages, update to release the + * correct amount below. + */ + shm->num_pages = len / PAGE_SIZE; + ret = ERR_PTR(-ENOMEM); + goto err_put_shm_pages; } /* |