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authorCarlos Llamas <cmllamas@google.com>2024-03-30 19:01:14 +0000
committerLee Jones <joneslee@google.com>2024-04-18 15:48:54 +0100
commite6bddd0827bd4879ef7236e2792bcc3f00cb8a55 (patch)
tree5fb71e365a0d219b1bef315c5d8c93709d249767
parentb26824bed88d7ef26dcfc12d6ccc9a5176df6fa1 (diff)
downloadcommon-android13-5.10-2024-03.tar.gz
FROMLIST: binder: check offset alignment in binder_get_object()android13-5.10-2024-03
Commit 6d98eb95b450 ("binder: avoid potential data leakage when copying txn") introduced changes to how binder objects are copied. In doing so, it unintentionally removed an offset alignment check done through calls to binder_alloc_copy_from_buffer() -> check_buffer(). These calls were replaced in binder_get_object() with copy_from_user(), so now an explicit offset alignment check is needed here. This avoids later complications when unwinding the objects gets harder. It is worth noting this check existed prior to commit 7a67a39320df ("binder: add function to copy binder object from buffer"), likely removed due to redundancy at the time. Fixes: 6d98eb95b450 ("binder: avoid potential data leakage when copying txn") Cc: <stable@vger.kernel.org> Acked-by: Todd Kjos <tkjos@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Bug: 334156990 Bug: 320661088 Link: https://lore.kernel.org/all/20240330190115.1877819-1-cmllamas@google.com/ Signed-off-by: Carlos Llamas <cmllamas@google.com> (cherry picked from https://android-review.googlesource.com/q/commit:d76a750f6ffe72431a2c467e85a5ac69366287d1) Merged-In: Iaddabaa28de7ba7b7d35dbb639d38ca79dbc5077 Change-Id: Iaddabaa28de7ba7b7d35dbb639d38ca79dbc5077 (cherry picked from commit 0379ec545054248181a798ef46bb2acc3b71d570) Signed-off-by: Lee Jones <joneslee@google.com>
-rw-r--r--drivers/android/binder.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index eec637df8605..abec538a0294 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1837,8 +1837,10 @@ static size_t binder_get_object(struct binder_proc *proc,
size_t object_size = 0;
read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset);
- if (offset > buffer->data_size || read_size < sizeof(*hdr))
+ if (offset > buffer->data_size || read_size < sizeof(*hdr) ||
+ !IS_ALIGNED(offset, sizeof(u32)))
return 0;
+
if (u) {
if (copy_from_user(object, u + offset, read_size))
return 0;