[PATCH] crypto: x86/aes-gcm: Disable FPU around skcipher_walk_done().

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

kernel_fpu_begin() disables preemption. gcm_crypt() has a
skcipher_walk_done() invocation within a preempt disabled section.
skcipher_walk_done() can invoke kfree() which requires sleeping locks on
PREEMPT_RT and must not be invoked with disabled preemption.

Keep FPU access enabled while skcipher_walk_done() is invoked.

Fixes: b06affb1cb580 ("crypto: x86/aes-gcm - add VAES and AVX512 / AVX10 optimized AES-GCM")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/x86/crypto/aesni-intel_glue.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index cd37de5ec4046..be92e4c3f9c7f 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -1403,7 +1403,9 @@ gcm_crypt(struct aead_request *req, int flags)
 			aes_gcm_update(key, le_ctr, ghash_acc,
 				       walk.src.virt.addr, walk.dst.virt.addr,
 				       nbytes, flags);
+			kernel_fpu_end();
 			err = skcipher_walk_done(&walk, 0);
+			kernel_fpu_begin();
 			/*
 			 * The low word of the counter isn't used by the
 			 * finalize, so there's no need to increment it here.
-- 
2.45.2