selftests/bpf: Test packet range of pointers sharing an idgrafted

Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.

These refused a valid program or accepted an out-of-bounds access before
the fix:

- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
  8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
  bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
  was accepted.

These pass with and without the fix and cover nearby paths:

- subtract an unknown scalar from a checked pointer and load below it
  (the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
  the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
  one byte past the checked range: the load is refused, and the copy
  has the range of the check.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/include/xen/arm/hypercall.h b/include/xen/arm/hypercall.h
new file mode 100644
index 000000000..9d7dd1c65
--- /dev/null
+++ b/include/xen/arm/hypercall.h
@@ -0,0 +1,76 @@
+/******************************************************************************
+ * hypercall.h
+ *
+ * Linux-specific hypervisor handling.
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef _ASM_ARM_XEN_HYPERCALL_H
+#define _ASM_ARM_XEN_HYPERCALL_H
+
+#include <linux/bug.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/platform.h>
+
+struct xen_dm_op_buf;
+
+long privcmd_call(unsigned call, unsigned long a1,
+		unsigned long a2, unsigned long a3,
+		unsigned long a4, unsigned long a5);
+int HYPERVISOR_xen_version(int cmd, void *arg);
+int HYPERVISOR_console_io(int cmd, int count, char *str);
+int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
+int HYPERVISOR_sched_op(int cmd, void *arg);
+int HYPERVISOR_event_channel_op(int cmd, void *arg);
+unsigned long HYPERVISOR_hvm_op(int op, void *arg);
+int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
+int HYPERVISOR_physdev_op(int cmd, void *arg);
+int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
+int HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type);
+int HYPERVISOR_dm_op(domid_t domid, unsigned int nr_bufs,
+		     struct xen_dm_op_buf *bufs);
+int HYPERVISOR_platform_op_raw(void *arg);
+static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
+{
+	op->interface_version = XENPF_INTERFACE_VERSION;
+	return HYPERVISOR_platform_op_raw(op);
+}
+int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr);
+
+static inline int
+HYPERVISOR_suspend(unsigned long start_info_mfn)
+{
+	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
+
+	/* start_info_mfn is unused on ARM */
+	return HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
+}
+
+#endif /* _ASM_ARM_XEN_HYPERCALL_H */