Linux: Use After Free
CVE-2022-49489 is a high-severity use after 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 aa4cb188988dc6f1b3f4917d4dbc452150a5d871, ef10d0c68e8608848cd58fca2589685718426607, 134760263f6441741db0b2970e7face6b34b6d1c 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 0.28% 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 aa4cb188988dc6f1b3f4917d4dbc452150a5d871 or ef10d0c68e8608848cd58fca2589685718426607 or 134760263f6441741db0b2970e7face6b34b6d1c or ef4bdaac7cb5416f236613ed9337ff0ea8ee329b, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.247 or 5.4.198 or 5.10.121 or 5.15.46, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, aa4cb188988dc6f1b3f4917d4dbc452150a5d871; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, ef10d0c68e8608848cd58fca2589685718426607; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, 134760263f6441741db0b2970e7face6b34b6d1c; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, ef4bdaac7cb5416f236613ed9337ff0ea8ee329b; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, 97ac682b6f7d36be5d934f86c9911066540a68f1; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, 5b0adf5cbf3b74721e4e4c4e0cadc91b8df8bcc2; 25fdd5933e4c0f5fe2ea5cd59994f8ac5fbe90ef up to, but not including, fa5186b279ecf44b14fb435540d2065be91cb1ed; 4.19 | aa4cb188988dc6f1b3f4917d4dbc452150a5d871, ef10d0c68e8608848cd58fca2589685718426607, 134760263f6441741db0b2970e7face6b34b6d1c, ef4bdaac7cb5416f236613ed9337ff0ea8ee329b, 97ac682b6f7d36be5d934f86c9911066540a68f1, 5b0adf5cbf3b74721e4e4c4e0cadc91b8df8bcc2 |
| Linux | Linux Kernel | 4.19 up to, but not including, 4.19.247; 4.20 up to, but not including, 5.4.198; 5.5 up to, but not including, 5.10.121; 5.11 up to, but not including, 5.15.46; 5.16 up to, but not including, 5.17.14; 5.18 up to, but not including, 5.18.3 | 4.19.247, 5.4.198, 5.10.121, 5.15.46, 5.17.14, 5.18.3 |
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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/msm/disp/dpu1: set vbif hw config to NULL to avoid use after memory free during pm runtime resume BUG: Unable to handle kernel paging request at virtual address 006b6b6b6b6b6be3 Call trace: dpu_vbif_init_memtypes+0x40/0xb8 dpu_runtime_resume+0xcc/0x1c0 pm_generic_runtime_resume+0x30/0x44 __genpd_runtime_resume+0x68/0x7c genpd_runtime_resume+0x134/0x258 __rpm_callback+0x98/0x138 rpm_callback+0x30/0x88 rpm_resume+0x36c/0x49c __pm_runtime_resume+0x80/0xb0 dpu_core_irq_uninstall+0x30/0xb0 dpu_irq_uninstall+0x18/0x24 msm_drm_uninit+0xd8/0x16c Patchwork: https://patchwork.freedesktop.org/patch/483255/ [DB: fixed Fixes tag]
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
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/134760263f6441741db0b2970e7face6b34b6d1c
- git.kernel.org/stable/c/5b0adf5cbf3b74721e4e4c4e0cadc91b8df8bcc2
- git.kernel.org/stable/c/97ac682b6f7d36be5d934f86c9911066540a68f1
- git.kernel.org/stable/c/aa4cb188988dc6f1b3f4917d4dbc452150a5d871
- git.kernel.org/stable/c/ef10d0c68e8608848cd58fca2589685718426607
- git.kernel.org/stable/c/ef4bdaac7cb5416f236613ed9337ff0ea8ee329b
- git.kernel.org/stable/c/fa5186b279ecf44b14fb435540d2065be91cb1ed
Recent Use After Free vulnerabilities
- 7.8 High 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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