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 --- net/Kconfig.debug | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 net/Kconfig.debug (limited to 'net/Kconfig.debug') diff --git a/net/Kconfig.debug b/net/Kconfig.debug new file mode 100644 index 000000000..277fab8c4 --- /dev/null +++ b/net/Kconfig.debug @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config NET_DEV_REFCNT_TRACKER + bool "Enable net device refcount tracking" + depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET + select REF_TRACKER + default n + help + Enable debugging feature to track device references. + This adds memory and cpu costs. + +config NET_NS_REFCNT_TRACKER + bool "Enable networking namespace refcount tracking" + depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET + select REF_TRACKER + default n + help + Enable debugging feature to track netns references. + This adds memory and cpu costs. + +config DEBUG_NET + bool "Add generic networking debug" + depends on DEBUG_KERNEL && NET + help + Enable extra sanity checks in networking. + This is mostly used by fuzzers, but is safe to select. + +config DEBUG_NET_SMALL_RTNL + bool "Add extra per-netns mutex inside RTNL" + depends on DEBUG_KERNEL && NET && LOCK_DEBUGGING_SUPPORT + select PROVE_LOCKING + default n + help + rtnl_lock() is being replaced with rtnl_net_lock() that + acquires the global RTNL and a small per-netns RTNL mutex. + + During the conversion, rtnl_net_lock() just adds an extra + mutex in every RTNL scope and slows down the operations. + + Once the conversion completes, rtnl_lock() will be removed + and rtnetlink will gain per-netns scalability. -- cgit v1.3.1