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, 127 insertions, 0 deletions

diff --git a/drivers/message/fusion/mptlan.h b/drivers/message/fusion/mptlan.h
new file mode 100644
index 000000000..40b34f670
--- /dev/null
+++ b/drivers/message/fusion/mptlan.h
@@ -0,0 +1,127 @@
+/*
+ *  linux/drivers/message/fusion/mptlan.h
+ *      IP Over Fibre Channel device driver.
+ *      For use with LSI Fibre Channel PCI chip/adapters
+ *      running LSI Fusion MPT (Message Passing Technology) firmware.
+ *
+ *  Copyright (c) 2000-2008 LSI Corporation
+ *  (mailto:DL-MPTFusionLinux@lsi.com)
+ *
+ */
+/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
+/*
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; version 2 of the License.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    NO WARRANTY
+    THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR
+    CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT
+    LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT,
+    MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is
+    solely responsible for determining the appropriateness of using and
+    distributing the Program and assumes all risks associated with its
+    exercise of rights under this Agreement, including but not limited to
+    the risks and costs of program errors, damage to or loss of data,
+    programs or equipment, and unavailability or interruption of operations.
+
+    DISCLAIMER OF LIABILITY
+    NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY
+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND
+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+    USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED
+    HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
+
+/* mptlan.h */
+
+#ifndef LINUX_MPTLAN_H_INCLUDED
+#define LINUX_MPTLAN_H_INCLUDED
+/*****************************************************************************/
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/errno.h>
+// #include <linux/etherdevice.h>
+#include <linux/fcdevice.h>
+// #include <linux/fddidevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+
+#include <linux/uaccess.h>
+#include <asm/io.h>
+
+    /* Override mptbase.h by pre-defining these! */
+#define MODULEAUTHOR	"LSI Corporation"
+
+#include "mptbase.h"
+
+/*****************************************************************************/
+#define LANAME		"Fusion MPT LAN driver"
+#define LANVER		MPT_LINUX_VERSION_COMMON
+
+#ifdef MODULE
+MODULE_AUTHOR(MODULEAUTHOR);
+MODULE_DESCRIPTION(LANAME);
+#endif
+/*****************************************************************************/
+
+#define MPT_LAN_MAX_BUCKETS_OUT 256
+#define MPT_LAN_BUCKET_THRESH	18 /* 9 buckets in one message */
+#define MPT_LAN_BUCKETS_REMAIN_MISMATCH_THRESH 10
+#define MPT_LAN_RX_COPYBREAK	200
+#define MPT_LAN_TX_TIMEOUT	(1*HZ)
+#define MPT_TX_MAX_OUT_LIM      127
+
+#define MPT_LAN_MIN_MTU		96		/* RFC2625 */
+#define MPT_LAN_MAX_MTU		65280		/* RFC2625 */
+#define MPT_LAN_MTU             13312		/* Max perf range + lower mem
+						   usage than 16128 */
+
+#define MPT_LAN_NAA_RFC2625     0x1
+#define MPT_LAN_NAA_QLOGIC      0x2
+
+/* MPT LAN Reset and Suspend Resource Flags Defines */
+
+#define MPT_LAN_RESOURCE_FLAG_RETURN_POSTED_BUCKETS    0x01
+#define MPT_LAN_RESOURCE_FLAG_RETURN_PEND_TRANSMITS    0x02
+
+/*****************************************************************************/
+#ifdef MPT_LAN_IO_DEBUG
+#define dioprintk(x)  printk x
+#else
+#define dioprintk(x)  no_printk x
+#endif
+
+#ifdef MPT_LAN_DEBUG
+#define dlprintk(x)  printk x
+#else
+#define dlprintk(x)  no_printk x
+#endif
+
+#define NETDEV_TO_LANPRIV_PTR(d)	((struct mpt_lan_priv *)netdev_priv(d))
+#define NETDEV_PTR_TO_IOC_NAME_s(d)	(NETDEV_TO_LANPRIV_PTR(d)->mpt_dev->name)
+#define IOC_AND_NETDEV_NAMES_s_s(d)	NETDEV_PTR_TO_IOC_NAME_s(d), (d)->name
+
+/*****************************************************************************/
+#endif
+