Linux: Out-of-bounds Read
CVE-2024-56555 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 6b1be1da1f8279cf091266e71b5153c5b02aaff6, 011e69a1b23011c0db3af4b8293fdd4522cc97b0 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 6b1be1da1f8279cf091266e71b5153c5b02aaff6 or 011e69a1b23011c0db3af4b8293fdd4522cc97b0, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.4 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d579b04a52a183db47dfcb7a44304d7747d551e1 up to, but not including, 6b1be1da1f8279cf091266e71b5153c5b02aaff6; d579b04a52a183db47dfcb7a44304d7747d551e1 up to, but not including, 011e69a1b23011c0db3af4b8293fdd4522cc97b0; 6.12 | 6b1be1da1f8279cf091266e71b5153c5b02aaff6, 011e69a1b23011c0db3af4b8293fdd4522cc97b0 |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.12.4 | 6.12.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
| CVSS 3.1 | 7.1 | High | CISA (ADP) |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
Linux Kernel Out-of-Bounds Read Exploited
- 7.1 High severity
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