Linux: Use After Free
CVE-2023-53613 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 94a85474f5e3e518bdbf8c9f51cb343d734a04f7, 9c2f993b6ca903c030d58451b5bf9ea27d0d17fa, 03859868ab82d57bfdd0cea1bf31f9319a5dded0 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 0.15% 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 94a85474f5e3e518bdbf8c9f51cb343d734a04f7 or 9c2f993b6ca903c030d58451b5bf9ea27d0d17fa or 03859868ab82d57bfdd0cea1bf31f9319a5dded0 or f76db6781d76d8464ec2faa9752cc3fb2e4f6923, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.188 or 5.15.121 or 6.1.39 or 6.3.13, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, 94a85474f5e3e518bdbf8c9f51cb343d734a04f7; 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, 9c2f993b6ca903c030d58451b5bf9ea27d0d17fa; 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, 03859868ab82d57bfdd0cea1bf31f9319a5dded0; 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, f76db6781d76d8464ec2faa9752cc3fb2e4f6923; 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, 7310b84821f043dcf77d5e6aa0ad55dc1e10a11d; 0b07ce872a9eca1ff88c0eb7f6e92dde127d21ca up to, but not including, 6d24b170a9db0456f577b1ab01226a2254c016a8; 5.10 | 94a85474f5e3e518bdbf8c9f51cb343d734a04f7, 9c2f993b6ca903c030d58451b5bf9ea27d0d17fa, 03859868ab82d57bfdd0cea1bf31f9319a5dded0, f76db6781d76d8464ec2faa9752cc3fb2e4f6923, 7310b84821f043dcf77d5e6aa0ad55dc1e10a11d, 6d24b170a9db0456f577b1ab01226a2254c016a8 |
| Linux | Linux Kernel | 5.10 up to, but not including, 5.10.188; 5.11 up to, but not including, 5.15.121; 5.16 up to, but not including, 6.1.39; 6.2 up to, but not including, 6.3.13; 6.4 up to, but not including, 6.4.4 | 5.10.188, 5.15.121, 6.1.39, 6.3.13, 6.4.4 |
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
- 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.
Official description
In the Linux kernel, the following vulnerability has been resolved: dax: Fix dax_mapping_release() use after free A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: <TASK> [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it drops from its release callback. Arrange for a dax_mapping to pin its parent dev_dax instance until dax_mapping_release().
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/03859868ab82d57bfdd0cea1bf31f9319a5dded0
- git.kernel.org/stable/c/6d24b170a9db0456f577b1ab01226a2254c016a8
- git.kernel.org/stable/c/7310b84821f043dcf77d5e6aa0ad55dc1e10a11d
- git.kernel.org/stable/c/94a85474f5e3e518bdbf8c9f51cb343d734a04f7
- git.kernel.org/stable/c/9c2f993b6ca903c030d58451b5bf9ea27d0d17fa
- git.kernel.org/stable/c/f76db6781d76d8464ec2faa9752cc3fb2e4f6923
Recent Use After Free vulnerabilities
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