Description

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...

Classification

CVE ID: CVE-2024-56772

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 11.48% (scored less or equal to compared to others)

EPSS Date: 2025-02-06 (when was this score calculated)

References

https://git.kernel.org/stable/c/3213b92754b94dec6836e8b4d6ec7d224a805b61
https://git.kernel.org/stable/c/39e21403c978862846fa68b7f6d06f9cca235194

Timeline