From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id 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 Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/gdb/vmlinux-gdb.py | 52 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 scripts/gdb/vmlinux-gdb.py (limited to 'scripts/gdb/vmlinux-gdb.py') diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py new file mode 100644 index 000000000..d4eeed450 --- /dev/null +++ b/scripts/gdb/vmlinux-gdb.py @@ -0,0 +1,52 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# loader module +# +# Copyright (c) Siemens AG, 2012, 2013 +# +# Authors: +# Jan Kiszka +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import os + +sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)) + "/scripts/gdb") + +try: + gdb.parse_and_eval("0") + gdb.execute("", to_string=True) +except: + gdb.write("NOTE: gdb 7.2 or later required for Linux helper scripts to " + "work.\n") +else: + import linux.constants + if linux.constants.LX_CONFIG_DEBUG_INFO_REDUCED: + raise gdb.GdbError("Reduced debug information will prevent GDB " + "from having complete types.\n") + import linux.utils + import linux.symbols + import linux.modules + import linux.dmesg + import linux.tasks + import linux.config + import linux.cpus + import linux.lists + import linux.rbtree + import linux.proc + import linux.timerlist + import linux.clk + import linux.genpd + import linux.device + import linux.vfs + import linux.pgtable + import linux.radixtree + import linux.interrupts + import linux.mm + import linux.stackdepot + import linux.page_owner + import linux.slab + import linux.vmalloc + import linux.kasan -- cgit v1.3.1