| Summary: |
VUL-0: CVE-2023-52609: kernel: binder: fix race between mmput() and do_exit() |
| Product: |
[Novell Products] SUSE Security Incidents
|
Reporter: |
SMASH SMASH <smash_bz> |
| Component: |
Incidents | Assignee: |
Security Team bot <security-team> |
| Status: |
RESOLVED
UPSTREAM
|
QA Contact: |
Security Team bot <security-team> |
| Severity: |
Normal
|
|
|
| Priority: |
P5 - None
|
CC: |
gabriele.sonnu
|
| Version: |
unspecified | |
|
| Target Milestone: |
--- | |
|
| Hardware: |
Other | |
|
| OS: |
Other | |
|
| URL: |
https://smash.suse.de/issue/398025/
|
| Whiteboard: |
|
|
Found By:
|
Security Response Team
|
Services Priority:
|
|
|---|
|
Business Priority:
|
|
Blocker:
|
---
|
|---|
|
Marketing QA Status:
|
---
|
IT Deployment:
|
---
|
|---|
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: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-52609 https://www.cve.org/CVERecord?id=CVE-2023-52609 https://git.kernel.org/stable/c/252a2a5569eb9f8d16428872cc24dea1ac0bb097 https://git.kernel.org/stable/c/6696f76c32ff67fec26823fc2df46498e70d9bf3 https://git.kernel.org/stable/c/67f16bf2cc1698fd50e01ee8a2becc5a8e6d3a3e https://git.kernel.org/stable/c/77d210e8db4d61d43b2d16df66b1ec46fad2ee01 https://git.kernel.org/stable/c/7e7a0d86542b0ea903006d3f42f33c4f7ead6918 https://git.kernel.org/stable/c/95b1d336b0642198b56836b89908d07b9a0c9608 https://git.kernel.org/stable/c/98fee5bee97ad47b527a997d5786410430d1f0e9 https://git.kernel.org/stable/c/9a9ab0d963621d9d12199df9817e66982582d5a5