crypto: eip93 - fix hmac setkey algo selection

In the Linux kernel, the following vulnerability has been resolved:

crypto: eip93 - fix hmac setkey algo selection

eip93_hmac_setkey() allocates a temporary ahash transform for

computing HMAC ipad/opad key material. The allocation uses the

driver-specific cra_driver_name (e.g. "sha256-eip93") but passes

CRYPTO_ALG_ASYNC as the mask, which excludes async algorithms.

Since the EIP93 hash algorithms are the only ones registered

under those driver names and they are inherently async, the

lookup is self-contradictory and always fails with -ENOENT.

When called from the AEAD setkey path, this failure leaves the

SA record partially initialized with zeroed digest fields. A

subsequent crypto operation then dereferences a NULL pointer in

the request context, resulting in a kernel panic:

```

pc : eip93_aead_handle_result+0xc8c/0x1240 [crypto_hw_eip93]

lr : eip93_aead_handle_result+0xbec/0x1240 [crypto_hw_eip93]

sp : ffffffc082feb820

x29: ffffffc082feb820 x28: ffffff8011043980 x27: 0000000000000000

x26: 0000000000000000 x25: ffffffc078da0bc8 x24: 0000000091043980

x23: ffffff8004d59e50 x22: ffffff8004d59410 x21: ffffff8004d593c0

x20: ffffff8004d593c0 x19: ffffff8004d4f300 x18: 0000000000000000

x17: 0000000000000000 x16: 0000000000000000 x15: 0000007fda7aa498

x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000

x11: 0000000000000000 x10: fffffffff8127a80 x9 : 0000000000000000

x8 : ffffff8004d4f380 x7 : 0000000000000000 x6 : 000000000000003f

x5 : 0000000000000040 x4 : 0000000000000008 x3 : 0000000000000009

x2 : 0000000000000008 x1 : 0000000028000003 x0 : ffffff8004d388c0

Code: 910142b6 f94012e0 f9002aa0 f90006d3 (f9400740)

```

The reported symbol eip93_aead_handle_result+0xc8c is a

resolution artifact from static functions being merged under

the nearest exported symbol. Decoding the faulting sequence:

```

910142b6 ADD X22, X21, #0x50

f94012e0 LDR X0, [X23, #0x20]

f9002aa0 STR X0, [X21, #0x50]

f90006d3 STR X19, [X22, #0x8]

f9400740 LDR X0, [X26, #0x8]

```

The faulting LDR at [X26, #0x8] is loading ctx->flags

(offset 8 in eip93_hash_ctx), where ctx has been resolved

to NULL from a partially initialized or unreachable

transform context following the failed setkey.

Fix this by dropping the CRYPTO_ALG_ASYNC mask from the

crypto_alloc_ahash() call. The code already handles async

completion correctly via crypto_wait_req(), so there is no

requirement to restrict the lookup to synchronous algorithms.

Note that hashing a single 64-byte block through the hardware

is likely slower than doing it in software due to the DMA

round-trip overhead, but offloading it may still spare CPU

cycles on the slower embedded cores where this IP is found.

[Detailed investigation report of this bug]