From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- scripts/headers_install.sh | 75 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100755 scripts/headers_install.sh (limited to 'scripts/headers_install.sh') diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh new file mode 100755 index 000000000..2f1d1767c --- /dev/null +++ b/scripts/headers_install.sh @@ -0,0 +1,75 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +if [ $# -ne 2 ] +then + echo "Usage: headers_install.sh INFILE OUTFILE" + echo + echo "Prepares kernel header files for use by user space, by removing" + echo "all compiler.h definitions and #includes, removing any" + echo "#ifdef __KERNEL__ sections, and putting __underscores__ around" + echo "asm/inline/volatile keywords." + echo + echo "INFILE: header file to operate on" + echo "OUTFILE: output file which the processed header is written to" + + exit 1 +fi + +# Grab arguments +INFILE=$1 +OUTFILE=$2 +TMPFILE=$OUTFILE.tmp + +trap 'rm -f $OUTFILE $TMPFILE' EXIT + +# SPDX-License-Identifier with GPL variants must have "WITH Linux-syscall-note" +if [ -n "$(sed -n -e "/SPDX-License-Identifier:.*GPL-/{/WITH Linux-syscall-note/!p}" $INFILE)" ]; then + echo "error: $INFILE: missing \"WITH Linux-syscall-note\" for SPDX-License-Identifier" >&2 + exit 1 +fi + +sed -E -e ' + s/([[:space:](])(__user|__force|__iomem)[[:space:]]/\1/g + s/__attribute_const__([[:space:]]|$)/\1/g + s@^#include @@ + s/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g + s/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g + s@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @ + s/__ASSEMBLY__/__ASSEMBLER__/g +' $INFILE > $TMPFILE || exit 1 + +scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ $TMPFILE > $OUTFILE +[ $? -gt 1 ] && exit 1 + +# Remove /* ... */ style comments, and find CONFIG_ references in code +configs=$(sed -e ' +:comment + s:/\*[^*][^*]*:/*: + s:/\*\*\**\([^/]\):/*\1: + t comment + s:/\*\*/: : + t comment + /\/\*/! b check + N + b comment +:print + P + D +:check + s:^\(CONFIG_[[:alnum:]_]*\):\1\n: + t print + s:^[[:alnum:]_][[:alnum:]_]*:: + s:^[^[:alnum:]_][^[:alnum:]_]*:: + t check + d +' $OUTFILE) + +for c in $configs +do + echo "error: $INFILE: leak $c to user-space" >&2 + exit 1 +done + +rm -f $TMPFILE +trap - EXIT -- cgit v1.3.1