CVE-2023-52468: class: fix use-after-free in class_register()
First published: Sun Feb 25 2024(Updated: )
In the Linux kernel, the following vulnerability has been resolved: class: fix use-after-free in class_register() The lock_class_key is still registered and can be found in lock_keys_hash hlist after subsys_private is freed in error handler path.A task who iterate over the lock_keys_hash later may cause use-after-free.So fix that up and unregister the lock_class_key before kfree(cp). On our platform, a driver fails to kset_register because of creating duplicate filename '/class/xxx'.With Kasan enabled, it prints a invalid-access bug report. KASAN bug report: BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252 Pointer tag: [15], memory tag: [fe] CPU: 7 PID: 252 Comm: modprobe Tainted: G W 6.6.0-mainline-maybe-dirty #1 Call trace: dump_backtrace+0x1b0/0x1e4 show_stack+0x2c/0x40 dump_stack_lvl+0xac/0xe0 print_report+0x18c/0x4d8 kasan_report+0xe8/0x148 __hwasan_store8_noabort+0x88/0x98 lockdep_register_key+0x19c/0x1bc class_register+0x94/0x1ec init_module+0xbc/0xf48 [rfkill] do_one_initcall+0x17c/0x72c do_init_module+0x19c/0x3f8 ... Memory state around the buggy address: ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe >ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access not use-after-free here.In this case, modprobe is manipulating the corrupted lock_keys_hash hlish where lock_class_key is already freed before. It's worth noting that this only can happen if lockdep is enabled, which is not true for normal system.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | >=6.4.0<6.6.14 | |
| Linux Linux kernel | >=6.7.0<6.7.2 | |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.11.10-1 |
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Reference Links
- https://git.kernel.org/stable/c/0f1486dafca3398c4c46b9f6e6452fa27e73b559
- https://git.kernel.org/stable/c/93ec4a3b76404bce01bd5c9032bef5df6feb1d62
- https://git.kernel.org/stable/c/b57196a5ec5e4c0ffecde8348b085b778c7dce04
- https://launchpad.net/bugs/cve/CVE-2023-52468
- https://git.kernel.org/linus/93ec4a3b76404bce01bd5c9032bef5df6feb1d62
- https://security-tracker.debian.org/tracker/CVE-2023-52468
- https://git.kernel.org/linus/93ec4a3b76404bce01bd5c9032bef5df6feb1d62 (6.8-rc1)
- https://www.cve.org/CVERecord?id=CVE-2023-52468
- https://ubuntu.com/security/notices/USN-6818-1
- https://ubuntu.com/security/notices/USN-6819-1
- https://ubuntu.com/security/notices/USN-6818-2
- https://ubuntu.com/security/notices/USN-6819-2
- https://ubuntu.com/security/notices/USN-6819-3
- https://ubuntu.com/security/notices/USN-6818-3
- https://ubuntu.com/security/notices/USN-6818-4
- https://ubuntu.com/security/notices/USN-6819-4
- https://nvd.nist.gov/vuln/detail/CVE-2023-52468
- https://git.kernel.org/linus/dcfbb67e48a2becfce7990386e985b9c45098ee5
- https://ubuntu.com/security/CVE-2023-52468
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