In the Linux kernel, the following vulnerability has been resolved: binder: fix OOB in binder_add_freeze_work() In binder_add_freeze_work() we iterate over the proc->nodes with the proc->inner_lock held. However, this lock is temporarily dropped to acquire the node->lock first (lock nesting order). This can race with binder_deferred_release() which removes the nodes from the proc->nodes rbtree and adds them into binder_dead_nodes list. This leads to a broken iteration in binder_add_freeze_work() as rb_next() will use data from binder_dead_nodes, triggering an out-of-bounds access: ================================================================== BUG: KASAN: global-out-of-bounds in rb_next+0xfc/0x124 Read of size 8 at addr ffffcb84285f7170 by task freeze/660 CPU: 8 UID: 0 PID: 660 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #18 Hardware name: linux,dummy-virt (DT) Call trace: rb_next+0xfc/0x124 binder_add_freeze_work+0x344/0x534 binder_ioctl+0x1e70/0x25ac __arm64_sys_ioctl+0x124/0x190 The buggy address belongs to the variable: binder_dead_nodes+0x10/0x40 [...] ================================================================== This is possible because proc->nodes (rbtree) and binder_dead_nodes (list) share entries in binder_node through a union: struct binder_node { [...] union { struct rb_node rb_node; struct hlist_node dead_node; }; Fix the race by checking that the proc is still alive. If not, simply break out of the iteration.
History

Mon, 30 Dec 2024 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 27 Dec 2024 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: binder: fix OOB in binder_add_freeze_work() In binder_add_freeze_work() we iterate over the proc->nodes with the proc->inner_lock held. However, this lock is temporarily dropped to acquire the node->lock first (lock nesting order). This can race with binder_deferred_release() which removes the nodes from the proc->nodes rbtree and adds them into binder_dead_nodes list. This leads to a broken iteration in binder_add_freeze_work() as rb_next() will use data from binder_dead_nodes, triggering an out-of-bounds access: ================================================================== BUG: KASAN: global-out-of-bounds in rb_next+0xfc/0x124 Read of size 8 at addr ffffcb84285f7170 by task freeze/660 CPU: 8 UID: 0 PID: 660 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #18 Hardware name: linux,dummy-virt (DT) Call trace: rb_next+0xfc/0x124 binder_add_freeze_work+0x344/0x534 binder_ioctl+0x1e70/0x25ac __arm64_sys_ioctl+0x124/0x190 The buggy address belongs to the variable: binder_dead_nodes+0x10/0x40 [...] ================================================================== This is possible because proc->nodes (rbtree) and binder_dead_nodes (list) share entries in binder_node through a union: struct binder_node { [...] union { struct rb_node rb_node; struct hlist_node dead_node; }; Fix the race by checking that the proc is still alive. If not, simply break out of the iteration.
Title binder: fix OOB in binder_add_freeze_work()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-12-27T14:23:01.650Z

Updated: 2025-01-20T06:22:54.361Z

Reserved: 2024-12-27T14:03:05.990Z

Link: CVE-2024-56555

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2024-12-27T15:15:14.297

Modified: 2024-12-27T15:15:14.297

Link: CVE-2024-56555

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-12-27T00:00:00Z

Links: CVE-2024-56555 - Bugzilla