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, 56 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/Kconfig b/drivers/crypto/ccp/Kconfig
new file mode 100644
index 000000000..f16a0f611
--- /dev/null
+++ b/drivers/crypto/ccp/Kconfig
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CRYPTO_DEV_CCP_DD
+	tristate "Secure Processor device driver"
+	depends on CPU_SUP_AMD || ARM64
+	default m
+	help
+	  Provides AMD Secure Processor device driver.
+	  If you choose 'M' here, this module will be called ccp.
+
+config CRYPTO_DEV_SP_CCP
+	bool "Cryptographic Coprocessor device"
+	default y
+	depends on CRYPTO_DEV_CCP_DD && DMADEVICES
+	select HW_RANDOM
+	select DMA_ENGINE
+	select CRYPTO_SHA1
+	select CRYPTO_SHA256
+	help
+	  Provides the support for AMD Cryptographic Coprocessor (CCP) device
+	  which can be used to offload encryption operations such as SHA, AES
+	  and more.
+
+config CRYPTO_DEV_CCP_CRYPTO
+	tristate "Encryption and hashing offload support"
+	default m
+	depends on CRYPTO_DEV_CCP_DD
+	depends on CRYPTO_DEV_SP_CCP
+	select CRYPTO_HASH
+	select CRYPTO_SKCIPHER
+	select CRYPTO_AUTHENC
+	select CRYPTO_RSA
+	select CRYPTO_LIB_AES
+	help
+	  Support for using the cryptographic API with the AMD Cryptographic
+	  Coprocessor. This module supports offload of SHA and AES algorithms.
+	  If you choose 'M' here, this module will be called ccp_crypto.
+
+config CRYPTO_DEV_SP_PSP
+	bool "Platform Security Processor (PSP) device"
+	default y
+	depends on CRYPTO_DEV_CCP_DD && X86_64 && AMD_IOMMU
+	select PCI_TSM if PCI
+	help
+	 Provide support for the AMD Platform Security Processor (PSP).
+	 The PSP is a dedicated processor that provides support for key
+	 management commands in Secure Encrypted Virtualization (SEV) mode,
+	 along with software-based Trusted Execution Environment (TEE) to
+	 enable third-party trusted applications.
+
+config CRYPTO_DEV_CCP_DEBUGFS
+	bool "Enable CCP Internals in DebugFS"
+	default n
+	depends on CRYPTO_DEV_SP_CCP
+	help
+	  Expose CCP device information such as operation statistics, feature
+	  information, and descriptor queue contents.