From: Todd Kjos <tkjos@android.com> mainline inclusion from mainline-v5.5-rc2 commit 16981742717b04644a41052570fb502682a315d2 category: bugfix bugzilla: 188431, https://gitee.com/src-openeuler/kernel/issues/I6DKVG CVE: CVE-2023-20938 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- For BINDER_TYPE_PTR and BINDER_TYPE_FDA transactions, the num_valid local was calculated incorrectly causing the range check in binder_validate_ptr() to miss out-of-bounds offsets. Fixes: bde4a19fc04f ("binder: use userspace pointer as base of buffer space") Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191213202531.55010-1-tkjos@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Reviewed-by: Zheng Yejian <zhengyejian1@huawei.com> Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/android/binder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index b8000984514e..b250ff3946d0 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3335,7 +3335,7 @@ static void binder_transaction(struct binder_proc *proc, binder_size_t parent_offset; struct binder_fd_array_object *fda = to_binder_fd_array_object(hdr); - size_t num_valid = (buffer_offset - off_start_offset) * + size_t num_valid = (buffer_offset - off_start_offset) / sizeof(binder_size_t); struct binder_buffer_object *parent = binder_validate_ptr(target_proc, t->buffer, @@ -3409,7 +3409,7 @@ static void binder_transaction(struct binder_proc *proc, t->buffer->user_data + sg_buf_offset; sg_buf_offset += ALIGN(bp->length, sizeof(u64)); - num_valid = (buffer_offset - off_start_offset) * + num_valid = (buffer_offset - off_start_offset) / sizeof(binder_size_t); ret = binder_fixup_parent(t, thread, bp, off_start_offset, -- 2.25.1