In the Linux kernel, the following vulnerability has been resolved:
binder: fix race between mmput() and do_exit()
Task A calls binder_update_page_range() to allocate and insert pages on
a remote address space from Task B. For this, Task A pins the remote mm
via mmget_not_zero() first. This can race with Task B do_exit() and the
final mmput() refcount decrement will come from Task A.
Task A | Task B
------------------+------------------
mmget_not_zero() |
| do_exit()
| exit_mm()
| mmput()
mmput() |
exit_mmap() |
remove_vma() |
fput() |
In this case, the work of ____fput() from Task B is queued up in Task A
as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup
work gets executed. However, Task A instead sleep, waiting for a reply
from Task B that never comes (it's dead).
This means the binder_deferred_release() is blocked until an unrelated
binder event forces Task A to go back to userspace. All the associated
death notifications will also be delayed until then.
In order to fix this use mmput_async() that will schedule the work in
the corresponding mm->async_put_work WQ instead of Task A.
References
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
No history.
Information
Published : 2024-03-18 11:15
Updated : 2025-03-10 15:28
NVD link : CVE-2023-52609
Mitre link : CVE-2023-52609
CVE.ORG link : CVE-2023-52609
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')