Linux: Double Free
CVE-2024-56708 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 029ac07bb92d2f7502d47a4916f197a8445d83bf, 2a80e710bbc088a2511c159ee4d910456c5f0832, 830cabb61113d92a425dd3038ccedbdfb3c8d079 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 0.25% 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 029ac07bb92d2f7502d47a4916f197a8445d83bf or 2a80e710bbc088a2511c159ee4d910456c5f0832 or 830cabb61113d92a425dd3038ccedbdfb3c8d079 or e5c7052664b61f9e2f896702d20552707d0ef60a, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.174 or 6.1.120 or 6.6.64 or 6.11.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, 029ac07bb92d2f7502d47a4916f197a8445d83bf; 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, 2a80e710bbc088a2511c159ee4d910456c5f0832; 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, 830cabb61113d92a425dd3038ccedbdfb3c8d079; 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, e5c7052664b61f9e2f896702d20552707d0ef60a; 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, db60326f2c47b079e36785ace621eb3002db2088; 10590a9d4f23e0a519730d79d39331df60ad2079 up to, but not including, fefaae90398d38a1100ccd73b46ab55ff4610fba; 5.11 | 029ac07bb92d2f7502d47a4916f197a8445d83bf, 2a80e710bbc088a2511c159ee4d910456c5f0832, 830cabb61113d92a425dd3038ccedbdfb3c8d079, e5c7052664b61f9e2f896702d20552707d0ef60a, db60326f2c47b079e36785ace621eb3002db2088, fefaae90398d38a1100ccd73b46ab55ff4610fba |
| Linux | Linux Kernel | 5.11 up to, but not including, 5.15.174; 5.16 up to, but not including, 6.1.120; 6.2 up to, but not including, 6.6.64; 6.7 up to, but not including, 6.11.11; 6.12 up to, but not including, 6.12.2 | 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2 |
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 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: EDAC/igen6: Avoid segmentation fault on module unload The segmentation fault happens because: During modprobe: 1. In igen6_probe(), igen6_pvt will be allocated with kzalloc() 2. In igen6_register_mci(), mci->pvt_info will point to &igen6_pvt->imc[mc] During rmmod: 1. In mci_release() in edac_mc.c, it will kfree(mci->pvt_info) 2. In igen6_remove(), it will kfree(igen6_pvt); Fix this issue by setting mci->pvt_info to NULL to avoid the double kfree.
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
- git.kernel.org/stable/c/029ac07bb92d2f7502d47a4916f197a8445d83bf
- git.kernel.org/stable/c/2a80e710bbc088a2511c159ee4d910456c5f0832
- git.kernel.org/stable/c/830cabb61113d92a425dd3038ccedbdfb3c8d079
- git.kernel.org/stable/c/db60326f2c47b079e36785ace621eb3002db2088
- git.kernel.org/stable/c/e5c7052664b61f9e2f896702d20552707d0ef60a
- git.kernel.org/stable/c/fefaae90398d38a1100ccd73b46ab55ff4610fba
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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