crypto: amlogic - avoid double cleanup in meson_crypto_probe()

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:
<TASK>
dump_stack_lvl+0x68/0xa0
print_report+0xcb/0x5e0
? __virt_addr_valid+0x21d/0x3f0
? kthread_destroy_worker+0xb2/0xd0
? kthread_destroy_worker+0xb2/0xd0
kasan_report+0xca/0x100
? kthread_destroy_worker+0xb2/0xd0
kthread_destroy_worker+0xb2/0xd0
meson_crypto_probe+0x4d0/0xc10 [amlogic_gxl_crypto]
platform_probe+0x99/0x140
really_probe+0x1c6/0x6a0
? __pfx___device_attach_driver+0x10/0x10
__driver_probe_device+0x248/0x310
? acpi_driver_match_device+0xb0/0x100
driver_probe_device+0x48/0x210
? __pfx___device_attach_driver+0x10/0x10
__device_attach_driver+0x160/0x320
bus_for_each_drv+0x104/0x190
? __pfx_bus_for_each_drv+0x10/0x10
? _raw_spin_unlock_irqrestore+0x2c/0x50
__device_attach+0x19d/0x3b0
? __pfx___device_attach+0x10/0x10
? do_raw_spin_unlock+0x53/0x220
device_initial_probe+0x78/0xa0
bus_probe_device+0x5b/0x130
device_add+0xcfd/0x1430
? __pfx_device_add+0x10/0x10
? insert_resource+0x34/0x50
? lock_release+0xc9/0x290
platform_device_add+0x24e/0x590
? __pfx_meson_crypto_probe_repro_init+0x10/0x10 [meson_crypto_probe_repro]
meson_crypto_probe_repro_init+0x330/0xff0 [meson_crypto_probe_repro]
do_one_initcall+0xc0/0x450
? __pfx_do_one_initcall+0x10/0x10
? _raw_spin_unlock_irqrestore+0x2c/0x50
? __create_object+0x59/0x80
? kasan_unpoison+0x27/0x60
do_init_module+0x27b/0x7d0
? __pfx_do_init_module+0x10/0x10
? kasan_quarantine_put+0x84/0x1d0
? kfree+0x32c/0x510
? load_module+0x561e/0x5ff0
load_module+0x54fe/0x5ff0
? __pfx_load_module+0x10/0x10
? security_file_permission+0x20/0x40
? kernel_read_file+0x23d/0x6e0
? mmap_region+0x235/0x4a0
? __pfx_kernel_read_file+0x10/0x10
? __file_has_perm+0x2c0/0x3e0
init_module_from_file+0x158/0x180
? __pfx_init_module_from_file+0x10/0x10
? __lock_acquire+0x45a/0x1ba0
? idempotent_init_module+0x315/0x610
? lock_release+0xc9/0x290
? lock
---truncated---