x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
new file mode 100644
index 000000000..e93f2f82b
--- /dev/null
+++ b/drivers/crypto/aspeed/Kconfig
@@ -0,0 +1,57 @@
+config CRYPTO_DEV_ASPEED
+	tristate "Support for Aspeed cryptographic engine driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	select CRYPTO_ENGINE
+	help
+	  Hash and Crypto Engine (HACE) is designed to accelerate the
+	  throughput of hash data digest, encryption and decryption.
+
+	  Select y here to have support for the cryptographic driver
+	  available on Aspeed SoC.
+
+config CRYPTO_DEV_ASPEED_DEBUG
+	bool "Enable Aspeed crypto debug messages"
+	depends on CRYPTO_DEV_ASPEED
+	help
+	  Print Aspeed crypto debugging messages if you use this
+	  option to ask for those messages.
+	  Avoid enabling this option for production build to
+	  minimize driver timing.
+
+config CRYPTO_DEV_ASPEED_HACE_HASH
+	bool "Enable Aspeed Hash & Crypto Engine (HACE) hash"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_SHA1
+	select CRYPTO_SHA256
+	select CRYPTO_SHA512
+	select CRYPTO_HMAC
+	help
+	  Select here to enable Aspeed Hash & Crypto Engine (HACE)
+	  hash driver.
+	  Supports multiple message digest standards, including
+	  SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, and so on.
+
+config CRYPTO_DEV_ASPEED_HACE_CRYPTO
+	bool "Enable Aspeed Hash & Crypto Engine (HACE) crypto"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_AES
+	select CRYPTO_DES
+	select CRYPTO_ECB
+	select CRYPTO_CBC
+	select CRYPTO_CTR
+	help
+	  Select here to enable Aspeed Hash & Crypto Engine (HACE)
+	  crypto driver.
+	  Supports AES/DES symmetric-key encryption and decryption
+	  with ECB/CBC/CTR options.
+
+config CRYPTO_DEV_ASPEED_ACRY
+	bool "Enable Aspeed ACRY RSA Engine"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_ENGINE
+	select CRYPTO_RSA
+	help
+	  Select here to enable Aspeed ECC/RSA Engine (ACRY)
+	  RSA driver.
+	  Supports 256 bits to 4096 bits RSA encryption/decryption
+	  and signature/verification.