Linux: Double Free
CVE-2024-50276 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 2cf0e77f5a0aa1ff336aa71743eda55c73902187, 1325e838089da25217f4b403318a270fcdf88f34, 91c9daa21f3ff8668f9e1d6c860024ce7ad64137 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 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 2cf0e77f5a0aa1ff336aa71743eda55c73902187 or 1325e838089da25217f4b403318a270fcdf88f34 or 91c9daa21f3ff8668f9e1d6c860024ce7ad64137 or 1f26339b2ed63d1e8e18a18674fb73a392f3660e, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.117 or 6.6.61 or 6.11.8, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 2f207cbf0dd44278af2aa3ff0fc95b0f97cc4e4c up to, but not including, 2cf0e77f5a0aa1ff336aa71743eda55c73902187; 2f207cbf0dd44278af2aa3ff0fc95b0f97cc4e4c up to, but not including, 1325e838089da25217f4b403318a270fcdf88f34; 2f207cbf0dd44278af2aa3ff0fc95b0f97cc4e4c up to, but not including, 91c9daa21f3ff8668f9e1d6c860024ce7ad64137; 2f207cbf0dd44278af2aa3ff0fc95b0f97cc4e4c up to, but not including, 1f26339b2ed63d1e8e18a18674fb73a392f3660e; 5.17 | 2cf0e77f5a0aa1ff336aa71743eda55c73902187, 1325e838089da25217f4b403318a270fcdf88f34, 91c9daa21f3ff8668f9e1d6c860024ce7ad64137, 1f26339b2ed63d1e8e18a18674fb73a392f3660e |
| Linux | Linux Kernel | 5.17 up to, but not including, 6.1.117; 6.2 up to, but not including, 6.6.61; 6.7 up to, but not including, 6.11.8; 6.12 | 6.1.117, 6.6.61, 6.11.8 |
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
- HighData or code can be modified at will.
- 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:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: vertexcom: mse102x: Fix possible double free of TX skb The scope of the TX skb is wider than just mse102x_tx_frame_spi(), so in case the TX skb room needs to be expanded, we should free the the temporary skb instead of the original skb. Otherwise the original TX skb pointer would be freed again in mse102x_tx_work(), which leads to crashes: Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G D 6.6.23 Hardware name: chargebyte Charge SOM DC-ONE (DT) Workqueue: events mse102x_tx_work [mse102x] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_release_data+0xb8/0x1d8 lr : skb_release_data+0x1ac/0x1d8 sp : ffff8000819a3cc0 x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0 x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50 x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000 x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000 x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8 x8 : fffffc00001bc008 x7 : 0000000000000000 x6 : 0000000000000008 x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009 x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000 Call trace: skb_release_data+0xb8/0x1d8 kfree_skb_reason+0x48/0xb0 mse102x_tx_work+0x164/0x35c [mse102x] process_one_work+0x138/0x260 worker_thread+0x32c/0x438 kthread+0x118/0x11c ret_from_fork+0x10/0x20 Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Double Free vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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