Linux Kernel up to 6.12.3 kunit_init_suite use after free

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.12.3. The impacted element is the function kunit_init_suite. Performing a manipulation results in use after free. This vulnerability is reported as CVE-2024-56772. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.3. This affects the function kunit_init_suite. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: kunit: string-stream: Fix a UAF bug in kunit_init_suite() In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the kunit_suite_for_each_test_case() loop, the "suite->log = stream" has assigned before, and the error path only free the suite->log's stream memory but not set it to NULL, so the later string_stream_clear() of suite->log in kunit_init_suite() will cause below UAF bug. Set stream pointer to NULL after free to fix it. Unable to handle kernel paging request at virtual address 006440150000030d Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [006440150000030d] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts] CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458 Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST Hardware name: linux,dummy-virt (DT) pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : string_stream_clear+0x54/0x1ac lr : string_stream_clear+0x1a8/0x1ac sp : ffffffc080b47410 x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98 x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003 x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000 x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840 x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4 x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75 x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000 x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001 x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000 Call trace: string_stream_clear+0x54/0x1ac __kunit_test_suites_init+0x108/0x1d8 kunit_exec_run_tests+0xb8/0x100 kunit_module_notify+0x400/0x55c notifier_call_chain+0xfc/0x3b4 blocking_notifier_call_chain+0x68/0x9c do_init_module+0x24c/0x5c8 load_module+0x4acc/0x4e90 init_module_from_file+0xd4/0x128 idempotent_init_module+0x2d4/0x57c __arm64_sys_finit_module+0xac/0x100 invoke_syscall+0x6c/0x258 el0_svc_common.constprop.0+0x160/0x22c do_el0_svc+0x44/0x5c el0_svc+0x48/0xb8 el0t_64_sync_handler+0x13c/0x158 el0t_64_sync+0x190/0x194 Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2024-56772 since 12/29/2024. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/24/2025).

The vulnerability scanner Nessus provides a plugin with the ID 233479 (Ubuntu 24.10 : Linux kernel (Low Latency) vulnerabilities (USN-7380-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.4 eliminates this vulnerability. Applying the patch 3213b92754b94dec6836e8b4d6ec7d224a805b61/39e21403c978862846fa68b7f6d06f9cca235194 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (233479) and CERT Bund (WID-SEC-2025-0035). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Google Cloud Platform
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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