In the Linux kernel, the following vulnerability has been resolved:
crypto: amlogic - avoid double cleanup in meson_crypto_probe()
When meson_allocate_chanlist() fails after a partial allocation, it already
unwinds the allocated chanlist state through its local error path.
meson_crypto_probe() then jump to error_flow and calls
meson_free_chanlist() again, causing the same per-flow resources to be torn
down twice. In the reproduced failure path, the second teardown
re-entered crypto_engine_exit() on an already destroyed worker and KASAN
reported a slab-use-after-free in kthread_destroy_worker().
Prevent double-free by handling partial allocation failures locally within
meson_allocate_chanlist() and skipping the outer cleanup path.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available.
The bug was reproduced in a QEMU x86_64 guest booted with KASAN on v7.1,
using the reproducer under tools/testing/meson_crypto_probe. The reproducer
forces the second dma_alloc_attrs() call in the gxl-crypto probe path to
return NULL, making meson_allocate_chanlist() fail after partial
initialization. On the unpatched kernel this reliably triggered a
slab-use-after-free. With this fix applied, the same reproducer no longer
emits any KASAN report and the probe fails cleanly with -ENOMEM.
==================================================================
BUG: KASAN: slab-use-after-free in kthread_destroy_worker+0xb2/0xd0
Read of size 8 at addr ff1100010c057a68 by task insmod/265
CPU: 1 UID: 0 PID: 265 Comm: insmod Tainted: G O 7.1.0-rc2-00376-g810af9adc907-dirty #10 PREEMPT(lazy)
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
Unknown