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authorCarlos Llamas <cmllamas@google.com>2024-03-30 19:01:14 +0000
committerLee Jones <joneslee@google.com>2024-04-18 15:49:17 +0100
commit9116864df12906817c25edc6a97ae2849c229019 (patch)
treeb6bcc6d96dfa67a08c88a2c4e6e62bd3f3416852
parent532729b8d2b1c4638c8d934ccd85a87c360fa7ad (diff)
downloadcommon-android13-5.10-2024-02.tar.gz
FROMLIST: binder: check offset alignment in binder_get_object()android13-5.10-2024-02
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;