Linux: Use After Free
CVE-2024-27398 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 1b33d55fb7355e27f8c82cd4ecd560f162469249, 3212afd00e3cda790fd0583cb3eaef8f9575a014, 33a6e92161a78c1073d90e27abe28d746feb0a53 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 0.83% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 1b33d55fb7355e27f8c82cd4ecd560f162469249 or 3212afd00e3cda790fd0583cb3eaef8f9575a014 or 33a6e92161a78c1073d90e27abe28d746feb0a53 or 6a18eeb1b3bbc67c20d9609c31dca6a69b4bcde5, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.15 or 4.19.314 or 5.4.276 or 5.10.217, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 48669c81a65628ef234cbdd91b9395952c7c27fe up to, but not including, 1b33d55fb7355e27f8c82cd4ecd560f162469249; 37d7ae2b0578f2373674a755402ee722e96edc08 up to, but not including, 3212afd00e3cda790fd0583cb3eaef8f9575a014; a1073aad497d0d071a71f61b721966a176d50c08 up to, but not including, 33a6e92161a78c1073d90e27abe28d746feb0a53; ba316be1b6a00db7126ed9a39f9bee434a508043 up to, but not including, 6a18eeb1b3bbc67c20d9609c31dca6a69b4bcde5; ba316be1b6a00db7126ed9a39f9bee434a508043 up to, but not including, bfab2c1f7940a232cd519e82fff137e308abfd93; ba316be1b6a00db7126ed9a39f9bee434a508043 up to, but not including, 012363cb1bec5f33a7b94629ab2c1086f30280f2; ba316be1b6a00db7126ed9a39f9bee434a508043 up to, but not including, 50c2037fc28df870ef29d9728c770c8955d32178; ba316be1b6a00db7126ed9a39f9bee434a508043 up to, but not including, 483bc08181827fc475643272ffb69c533007e546; and 10 more ranges | 1b33d55fb7355e27f8c82cd4ecd560f162469249, 3212afd00e3cda790fd0583cb3eaef8f9575a014, 33a6e92161a78c1073d90e27abe28d746feb0a53, 6a18eeb1b3bbc67c20d9609c31dca6a69b4bcde5, bfab2c1f7940a232cd519e82fff137e308abfd93, 012363cb1bec5f33a7b94629ab2c1086f30280f2 |
| Fedora Project | Fedora | 39; 40 | Not stated |
| Linux | Linux Kernel | 4.14.263 up to, but not including, 4.15; 4.19.207 up to, but not including, 4.19.314; 5.4.148 up to, but not including, 5.4.276; 5.10.67 up to, but not including, 5.10.217; 5.13.19 up to, but not including, 5.14; 5.14.6 up to, but not including, 5.15.159; 5.16 up to, but not including, 6.1.91; 6.2 up to, but not including, 6.6.31; and 2 more ranges | 4.15, 4.19.314, 5.4.276, 5.10.217, 5.14, 5.15.159 |
| Debian | Debian Linux | 10.0 | Not stated |
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 | 8.0 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout When the sco connection is established and then, the sco socket is releasing, timeout_work will be scheduled to judge whether the sco disconnection is timeout. The sock will be deallocated later, but it is dereferenced again in sco_sock_timeout. As a result, the use-after-free bugs will happen. The root cause is shown below: Cleanup Thread | Worker Thread sco_sock_release | sco_sock_close | __sco_sock_close | sco_sock_set_timer | schedule_delayed_work | sco_sock_kill | (wait a time) sock_put(sk) //FREE | sco_sock_timeout | sock_hold(sk) //USE The KASAN report triggered by POC is shown below: [ 95.890016] ================================================================== [ 95.890496] BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x5e/0x1c0 [ 95.890755] Write of size 4 at addr ffff88800c388080 by task kworker/0:0/7 ... [ 95.890755] Workqueue: events sco_sock_timeout [ 95.890755] Call Trace: [ 95.890755] <TASK> [ 95.890755] dump_stack_lvl+0x45/0x110 [ 95.890755] print_address_description+0x78/0x390 [ 95.890755] print_report+0x11b/0x250 [ 95.890755] ? __virt_addr_valid+0xbe/0xf0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_report+0x139/0x170 [ 95.890755] ? update_load_avg+0xe5/0x9f0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_check_range+0x2c3/0x2e0 [ 95.890755] sco_sock_timeout+0x5e/0x1c0 [ 95.890755] process_one_work+0x561/0xc50 [ 95.890755] worker_thread+0xab2/0x13c0 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] kthread+0x279/0x300 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork+0x34/0x60 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork_asm+0x11/0x20 [ 95.890755] </TASK> [ 95.890755] [ 95.890755] Allocated by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] __kasan_kmalloc+0x86/0x90 [ 95.890755] __kmalloc+0x17f/0x360 [ 95.890755] sk_prot_alloc+0xe1/0x1a0 [ 95.890755] sk_alloc+0x31/0x4e0 [ 95.890755] bt_sock_alloc+0x2b/0x2a0 [ 95.890755] sco_sock_create+0xad/0x320 [ 95.890755] bt_sock_create+0x145/0x320 [ 95.890755] __sock_create+0x2e1/0x650 [ 95.890755] __sys_socket+0xd0/0x280 [ 95.890755] __x64_sys_socket+0x75/0x80 [ 95.890755] do_syscall_64+0xc4/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] Freed by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] kasan_save_free_info+0x40/0x50 [ 95.890755] poison_slab_object+0x118/0x180 [ 95.890755] __kasan_slab_free+0x12/0x30 [ 95.890755] kfree+0xb2/0x240 [ 95.890755] __sk_destruct+0x317/0x410 [ 95.890755] sco_sock_release+0x232/0x280 [ 95.890755] sock_close+0xb2/0x210 [ 95.890755] __fput+0x37f/0x770 [ 95.890755] task_work_run+0x1ae/0x210 [ 95.890755] get_signal+0xe17/0xf70 [ 95.890755] arch_do_signal_or_restart+0x3f/0x520 [ 95.890755] syscall_exit_to_user_mode+0x55/0x120 [ 95.890755] do_syscall_64+0xd1/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] The buggy address belongs to the object at ffff88800c388000 [ 95.890755] which belongs to the cache kmalloc-1k of size 1024 [ 95.890755] The buggy address is located 128 bytes inside of [ 95.890755] freed 1024-byte region [ffff88800c388000, ffff88800c388400) [ 95.890755] [ 95.890755] The buggy address belongs to the physical page: [ 95.890755] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800c38a800 pfn:0xc388 [ 95.890755] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 95.890755] ano ---truncated---
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/012363cb1bec5f33a7b94629ab2c1086f30280f2
- git.kernel.org/stable/c/1b33d55fb7355e27f8c82cd4ecd560f162469249
- git.kernel.org/stable/c/3212afd00e3cda790fd0583cb3eaef8f9575a014
- git.kernel.org/stable/c/33a6e92161a78c1073d90e27abe28d746feb0a53
- git.kernel.org/stable/c/483bc08181827fc475643272ffb69c533007e546
- git.kernel.org/stable/c/50c2037fc28df870ef29d9728c770c8955d32178
- git.kernel.org/stable/c/6a18eeb1b3bbc67c20d9609c31dca6a69b4bcde5
- git.kernel.org/stable/c/bfab2c1f7940a232cd519e82fff137e308abfd93
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2024/06/msg00019.htmlThird Party Advisory
- lists.debian.org/debian-lts-announce/2024/06/msg00020.htmlThird Party Advisory
- lists.fedoraproject.org/archives/list/[email protected]/message/DW2MIOIMOFUSNLHLRYX23A…Third Party Advisory
- lists.fedoraproject.org/archives/list/[email protected]/message/OTB4HWU2PTVW5NEYHHLOCX…Third Party Advisory
- security.netapp.com/advisory/ntap-20240912-0012/Third Party Advisory
Other references
- openwall.com/lists/oss-security/2024/11/29/1Mailing List
- openwall.com/lists/oss-security/2024/11/30/1Mailing List
- openwall.com/lists/oss-security/2024/11/30/2Mailing List
Recent Use After Free vulnerabilities
- 8.6 High severity
- 8.8 High severity
- 8.2 High severity
- 9.6 Critical severity
Google Chromium Visuals Use-After-Free Exploited
- 7.0 High severity
- 7.8 High severity
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