Linux: Use After Free
CVE-2024-38588 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 eea46baf145150910ba134f75a67106ba2222c1b, 1880a324af1c95940a7c954b6b937e86844a33bd, 8ea8ef5e42173560ac510e92a1cc797ffeea8831 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 0.24% 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 eea46baf145150910ba134f75a67106ba2222c1b or 1880a324af1c95940a7c954b6b937e86844a33bd or 8ea8ef5e42173560ac510e92a1cc797ffeea8831 or dbff5f0bfb2416b8b55c105ddbcd4f885e98fada, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.286 or 5.10.227 or 5.15.162 or 6.1.93, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, eea46baf145150910ba134f75a67106ba2222c1b; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, 1880a324af1c95940a7c954b6b937e86844a33bd; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, 8ea8ef5e42173560ac510e92a1cc797ffeea8831; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, dbff5f0bfb2416b8b55c105ddbcd4f885e98fada; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, 7b4881da5b19f65709f5c18c1a4d8caa2e496461; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, 66df065b3106964e667b37bf8f7e55ec69d0c1f6; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, 31310e373f4c8c74e029d4326b283e757edabc0b; ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b up to, but not including, e60b613df8b6253def41215402f72986fee3fc8d; and 1 more ranges | eea46baf145150910ba134f75a67106ba2222c1b, 1880a324af1c95940a7c954b6b937e86844a33bd, 8ea8ef5e42173560ac510e92a1cc797ffeea8831, dbff5f0bfb2416b8b55c105ddbcd4f885e98fada, 7b4881da5b19f65709f5c18c1a4d8caa2e496461, 66df065b3106964e667b37bf8f7e55ec69d0c1f6 |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | 3.7 up to, but not including, 5.4.286; 5.5 up to, but not including, 5.10.227; 5.11 up to, but not including, 5.15.162; 5.16 up to, but not including, 6.1.93; 6.2 up to, but not including, 6.6.33; 6.7 up to, but not including, 6.8.12; 6.9 up to, but not including, 6.9.3 | 5.4.286, 5.10.227, 5.15.162, 6.1.93, 6.6.33, 6.8.12 |
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: ftrace: Fix possible use-after-free issue in ftrace_location() KASAN reports a bug: BUG: KASAN: use-after-free in ftrace_location+0x90/0x120 Read of size 8 at addr ffff888141d40010 by task insmod/424 CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+ [...] Call Trace: <TASK> dump_stack_lvl+0x68/0xa0 print_report+0xcf/0x610 kasan_report+0xb5/0xe0 ftrace_location+0x90/0x120 register_kprobe+0x14b/0xa40 kprobe_init+0x2d/0xff0 [kprobe_example] do_one_initcall+0x8f/0x2d0 do_init_module+0x13a/0x3c0 load_module+0x3082/0x33d0 init_module_from_file+0xd2/0x130 __x64_sys_finit_module+0x306/0x440 do_syscall_64+0x68/0x140 entry_SYSCALL_64_after_hwframe+0x71/0x79 The root cause is that, in lookup_rec(), ftrace record of some address is being searched in ftrace pages of some module, but those ftrace pages at the same time is being freed in ftrace_release_mod() as the corresponding module is being deleted: CPU1 | CPU2 register_kprobes() { | delete_module() { check_kprobe_address_safe() { | arch_check_ftrace_location() { | ftrace_location() { | lookup_rec() // USE! | ftrace_release_mod() // Free! To fix this issue: 1. Hold rcu lock as accessing ftrace pages in ftrace_location_range(); 2. Use ftrace_location_range() instead of lookup_rec() in ftrace_location(); 3. Call synchronize_rcu() before freeing any ftrace pages both in ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().
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/1880a324af1c95940a7c954b6b937e86844a33bd
- git.kernel.org/stable/c/31310e373f4c8c74e029d4326b283e757edabc0b
- git.kernel.org/stable/c/66df065b3106964e667b37bf8f7e55ec69d0c1f6
- git.kernel.org/stable/c/7b4881da5b19f65709f5c18c1a4d8caa2e496461
- git.kernel.org/stable/c/8ea8ef5e42173560ac510e92a1cc797ffeea8831
- git.kernel.org/stable/c/dbff5f0bfb2416b8b55c105ddbcd4f885e98fada
- git.kernel.org/stable/c/e60b613df8b6253def41215402f72986fee3fc8d
- git.kernel.org/stable/c/eea46baf145150910ba134f75a67106ba2222c1b
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/03/msg00002.htmlMailing List, Third Party Advisory
Recent Use After Free vulnerabilities
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
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