In the Linux kernel, the following vulnerability has been resolved: binder: fix async_free_space accounting for empty parcels In 4.13, commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space") fixed a kernel structure visibility issue. As part of that patch, sizeof(void *) was used as the buffer size for 0-length data payloads so the driver could detect abusive clients sending 0-length asynchronous transactions to a server by enforcing limits on async_free_size. Unfortunately, on the "free" side, the accounting of async_free_space did not add the sizeof(void *) back. The result was that up to 8-bytes of async_free_space were leaked on every async transaction of 8-bytes or less. These small transactions are uncommon, so this accounting issue has gone undetected for several years. The fix is to use "buffer_size" (the allocated buffer size) instead of "size" (the logical buffer size) when updating the async_free_space during the free operation. These are the same except for this corner case of asynchronous transactions with payloads < 8 bytes.
History

Mon, 04 Nov 2024 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-02-27T09:44:02.071Z

Updated: 2024-12-19T07:32:07.436Z

Reserved: 2024-02-25T13:45:52.720Z

Link: CVE-2021-46935

cve-icon Vulnrichment

Updated: 2024-08-04T05:17:43.010Z

cve-icon NVD

Status : Modified

Published: 2024-02-27T10:15:07.957

Modified: 2024-11-21T06:34:58.220

Link: CVE-2021-46935

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-02-27T00:00:00Z

Links: CVE-2021-46935 - Bugzilla