Linux: Use After Free
CVE-2024-50150 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 2b0b33e8a58388fa9078f0fbe9af1900e6b08879, 2c15c4133d00f5da632fce60ed013fc31aa9aa58, 6af43ec3bf40f8b428d9134ffa7a291aecd60da8 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 2b0b33e8a58388fa9078f0fbe9af1900e6b08879 or 2c15c4133d00f5da632fce60ed013fc31aa9aa58 or 6af43ec3bf40f8b428d9134ffa7a291aecd60da8 or 87474406056891e4fdea0794e1f632b21b3dfa27, whichever matches your release line, or a later version.
- Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1.1 or a later version.
- Update Linux Kernel to 4.19.323 or 5.4.285 or 5.10.229 or 5.15.170, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 2b0b33e8a58388fa9078f0fbe9af1900e6b08879; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 2c15c4133d00f5da632fce60ed013fc31aa9aa58; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 6af43ec3bf40f8b428d9134ffa7a291aecd60da8; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 87474406056891e4fdea0794e1f632b21b3dfa27; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, bee1b68cb8bcee4fd3a8bde3a4886e0b1375dc4d; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 1ded6b12499e6dee9b0e1ceac633be36538f6fc2; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, 68a7c7fe322546be1464174c8d85874b8161deda; 8a37d87d72f0c69f837229c04d2fcd7117ea57e7 up to, but not including, befab3a278c59db0cc88c8799638064f6d3fd6f8; and 1 more ranges | 2b0b33e8a58388fa9078f0fbe9af1900e6b08879, 2c15c4133d00f5da632fce60ed013fc31aa9aa58, 6af43ec3bf40f8b428d9134ffa7a291aecd60da8, 87474406056891e4fdea0794e1f632b21b3dfa27, bee1b68cb8bcee4fd3a8bde3a4886e0b1375dc4d, 1ded6b12499e6dee9b0e1ceac633be36538f6fc2 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | before V1.1.1 | V1.1.1 |
| Linux | Linux Kernel | 4.19 up to, but not including, 4.19.323; 4.20 up to, but not including, 5.4.285; 5.5 up to, but not including, 5.10.229; 5.11 up to, but not including, 5.15.170; 5.16 up to, but not including, 6.1.115; 6.2 up to, but not including, 6.6.59; 6.7 up to, but not including, 6.11.6; 6.12 | 4.19.323, 5.4.285, 5.10.229, 5.15.170, 6.1.115, 6.6.59 |
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 | CNA |
| 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: usb: typec: altmode should keep reference to parent The altmode device release refers to its parent device, but without keeping a reference to it. When registering the altmode, get a reference to the parent and put it in the release function. Before this fix, when using CONFIG_DEBUG_KOBJECT_RELEASE, we see issues like this: [ 43.572860] kobject: 'port0.0' (ffff8880057ba008): kobject_release, parent 0000000000000000 (delayed 3000) [ 43.573532] kobject: 'port0.1' (ffff8880057bd008): kobject_release, parent 0000000000000000 (delayed 1000) [ 43.574407] kobject: 'port0' (ffff8880057b9008): kobject_release, parent 0000000000000000 (delayed 3000) [ 43.575059] kobject: 'port1.0' (ffff8880057ca008): kobject_release, parent 0000000000000000 (delayed 4000) [ 43.575908] kobject: 'port1.1' (ffff8880057c9008): kobject_release, parent 0000000000000000 (delayed 4000) [ 43.576908] kobject: 'typec' (ffff8880062dbc00): kobject_release, parent 0000000000000000 (delayed 4000) [ 43.577769] kobject: 'port1' (ffff8880057bf008): kobject_release, parent 0000000000000000 (delayed 3000) [ 46.612867] ================================================================== [ 46.613402] BUG: KASAN: slab-use-after-free in typec_altmode_release+0x38/0x129 [ 46.614003] Read of size 8 at addr ffff8880057b9118 by task kworker/2:1/48 [ 46.614538] [ 46.614668] CPU: 2 UID: 0 PID: 48 Comm: kworker/2:1 Not tainted 6.12.0-rc1-00138-gedbae730ad31 #535 [ 46.615391] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 [ 46.616042] Workqueue: events kobject_delayed_cleanup [ 46.616446] Call Trace: [ 46.616648] <TASK> [ 46.616820] dump_stack_lvl+0x5b/0x7c [ 46.617112] ? typec_altmode_release+0x38/0x129 [ 46.617470] print_report+0x14c/0x49e [ 46.617769] ? rcu_read_unlock_sched+0x56/0x69 [ 46.618117] ? __virt_addr_valid+0x19a/0x1ab [ 46.618456] ? kmem_cache_debug_flags+0xc/0x1d [ 46.618807] ? typec_altmode_release+0x38/0x129 [ 46.619161] kasan_report+0x8d/0xb4 [ 46.619447] ? typec_altmode_release+0x38/0x129 [ 46.619809] ? process_scheduled_works+0x3cb/0x85f [ 46.620185] typec_altmode_release+0x38/0x129 [ 46.620537] ? process_scheduled_works+0x3cb/0x85f [ 46.620907] device_release+0xaf/0xf2 [ 46.621206] kobject_delayed_cleanup+0x13b/0x17a [ 46.621584] process_scheduled_works+0x4f6/0x85f [ 46.621955] ? __pfx_process_scheduled_works+0x10/0x10 [ 46.622353] ? hlock_class+0x31/0x9a [ 46.622647] ? lock_acquired+0x361/0x3c3 [ 46.622956] ? move_linked_works+0x46/0x7d [ 46.623277] worker_thread+0x1ce/0x291 [ 46.623582] ? __kthread_parkme+0xc8/0xdf [ 46.623900] ? __pfx_worker_thread+0x10/0x10 [ 46.624236] kthread+0x17e/0x190 [ 46.624501] ? kthread+0xfb/0x190 [ 46.624756] ? __pfx_kthread+0x10/0x10 [ 46.625015] ret_from_fork+0x20/0x40 [ 46.625268] ? __pfx_kthread+0x10/0x10 [ 46.625532] ret_from_fork_asm+0x1a/0x30 [ 46.625805] </TASK> [ 46.625953] [ 46.626056] Allocated by task 678: [ 46.626287] kasan_save_stack+0x24/0x44 [ 46.626555] kasan_save_track+0x14/0x2d [ 46.626811] __kasan_kmalloc+0x3f/0x4d [ 46.627049] __kmalloc_noprof+0x1bf/0x1f0 [ 46.627362] typec_register_port+0x23/0x491 [ 46.627698] cros_typec_probe+0x634/0xbb6 [ 46.628026] platform_probe+0x47/0x8c [ 46.628311] really_probe+0x20a/0x47d [ 46.628605] device_driver_attach+0x39/0x72 [ 46.628940] bind_store+0x87/0xd7 [ 46.629213] kernfs_fop_write_iter+0x1aa/0x218 [ 46.629574] vfs_write+0x1d6/0x29b [ 46.629856] ksys_write+0xcd/0x13b [ 46.630128] do_syscall_64+0xd4/0x139 [ 46.630420] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 46.630820] [ 46.630946] Freed by task 48: [ 46.631182] kasan_save_stack+0x24/0x44 [ 46.631493] kasan_save_track+0x14/0x2d [ 46.631799] kasan_save_free_info+0x3f/0x4d [ 46.632144] __kasan_slab_free+0x37/0x45 [ 46.632474] ---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: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/1ded6b12499e6dee9b0e1ceac633be36538f6fc2
- git.kernel.org/stable/c/2b0b33e8a58388fa9078f0fbe9af1900e6b08879
- git.kernel.org/stable/c/2c15c4133d00f5da632fce60ed013fc31aa9aa58
- git.kernel.org/stable/c/68a7c7fe322546be1464174c8d85874b8161deda
- git.kernel.org/stable/c/6af43ec3bf40f8b428d9134ffa7a291aecd60da8
- git.kernel.org/stable/c/87474406056891e4fdea0794e1f632b21b3dfa27
- git.kernel.org/stable/c/bee1b68cb8bcee4fd3a8bde3a4886e0b1375dc4d
- git.kernel.org/stable/c/befab3a278c59db0cc88c8799638064f6d3fd6f8
Other references
Recent Use After Free vulnerabilities
- 7.0 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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