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authorCarlos Llamas <cmllamas@google.com>2024-03-30 19:01:14 +0000
committerPindar Yang <pindaryang@google.com>2024-04-03 07:17:30 +0000
commit7a2aa337ab8235460c1efa92a846eaeade5f2514 (patch)
treeea6d04234c4287987d7343d64938db8c8aa31a53
parent162fb647d635ced4ae8bf50c36a45205b470a02f (diff)
downloadcommon-android13-5.10-2024-01.tar.gz
FROMLIST: binder: check offset alignment in binder_get_object()android13-5.10-2024-01_r7android13-5.10-2024-01
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: 320661088 Bug: 332642003 Link: https://lore.kernel.org/all/20240330190115.1877819-1-cmllamas@google.com/ Signed-off-by: Carlos Llamas <cmllamas@google.com> Change-Id: Iaddabaa28de7ba7b7d35dbb639d38ca79dbc5077 Bug: 332642003 Signed-off-by: Pindar Yang <pindaryang@google.com> (cherry picked from commit 7859c5c9ebc6b0201ea804078a2329184b58ace5)
-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;