[PATCH v2 0/5] binder: fix issues with mremap()

From: Carlos Llamas

Date: Mon Aug 31 2026 - 23:05:51 EST


This is a follow up series fixing some pre-existing issues found by
sashiko during a review of an unrelated patchset here:
https://sashiko.dev/#/patchset/20260813193433.3318288-1-surenb@xxxxxxxxxx

The goal is to safely reject mremap() requests on binder's vma to
prevent pages from temporary leaking and accidental IPC tear-down.

--
v2:
- Set VM_DONTEXPAND in [1/5] and [2/5] per Sashiko's feedback.
- Check vma->vm_start to prevent incorrect ->close() in [3/5] per
Sashiko's feedback.

v1:
https://lore.kernel.org/all/20260831224145.169403-1-cmllamas@xxxxxxxxxx/

Carlos Llamas (5):
binder: set VM_DONTEXPAND
rust_binder: set VM_DONTEXPAND
binder: check vma->vm_start in binder_vma_close()
binder: reject mremap()
rust_binder: reject mremap()

drivers/android/binder.c | 12 +++++++++++-
drivers/android/binder/page_range.rs | 15 ++++++++++++---
drivers/android/binder/process.rs | 1 +
3 files changed, 24 insertions(+), 4 deletions(-)

--
2.55.0.897.gb25b4bd76c-goog