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| author | Jens Wiklander <jens.wiklander@linaro.org> | 2025-09-19 10:48:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-15 12:04:22 +0200 |
| commit | 6a7874ab814ce12003c46a92f7afc9b035c8e8e9 (patch) | |
| tree | 27cfeb191893202c7ad0e969c956171ebb5b3c18 | |
| parent | c07923f6a8729fc27ee652221a51702ff6654097 (diff) | |
| download | linux-6a7874ab814ce12003c46a92f7afc9b035c8e8e9.tar.gz linux-6a7874ab814ce12003c46a92f7afc9b035c8e8e9.tar.bz2 linux-6a7874ab814ce12003c46a92f7afc9b035c8e8e9.zip | |
tee: fix register_shm_helper()
commit d5cf5b37064b1699d946e8b7ab4ac7d7d101814c upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 2a7d253d9c55..8e50476eb71f 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -321,6 +321,14 @@ 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; } /* |