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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 10:43:19 +0200
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 07:58:36 -0700
commit6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch)
tree58e8288fead484f6755ad0815fc74c3742663761 /scripts/Makefile.ubsan
downloadlinux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.tar.gz
linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.zip
selftests/bpf: Reject graph kptr use after RCU unlockgrafted
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 <memxor@gmail.com> Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'scripts/Makefile.ubsan')
-rw-r--r--scripts/Makefile.ubsan28
1 files changed, 28 insertions, 0 deletions
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
new file mode 100644
index 000000000..734a102e6
--- /dev/null
+++ b/scripts/Makefile.ubsan
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Shared with KVM/arm64.
+export CFLAGS_UBSAN_TRAP := $(call cc-option,-fsanitize-trap=undefined,-fsanitize-undefined-trap-on-error)
+
+# Enable available and selected UBSAN features.
+ubsan-cflags-$(CONFIG_UBSAN_ALIGNMENT) += -fsanitize=alignment
+ubsan-cflags-$(CONFIG_UBSAN_BOUNDS_STRICT) += -fsanitize=bounds-strict
+ubsan-cflags-$(CONFIG_UBSAN_ARRAY_BOUNDS) += -fsanitize=array-bounds
+ubsan-cflags-$(CONFIG_UBSAN_LOCAL_BOUNDS) += -fsanitize=local-bounds
+ubsan-cflags-$(CONFIG_UBSAN_SHIFT) += -fsanitize=shift
+ubsan-cflags-$(CONFIG_UBSAN_DIV_ZERO) += -fsanitize=integer-divide-by-zero
+ubsan-cflags-$(CONFIG_UBSAN_UNREACHABLE) += -fsanitize=unreachable
+ubsan-cflags-$(CONFIG_UBSAN_BOOL) += -fsanitize=bool
+ubsan-cflags-$(CONFIG_UBSAN_ENUM) += -fsanitize=enum
+ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(CFLAGS_UBSAN_TRAP)
+
+export CFLAGS_UBSAN := $(ubsan-cflags-y)
+
+ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \
+ -DINTEGER_WRAP \
+ -fsanitize-undefined-ignore-overflow-pattern=all \
+ -fsanitize=signed-integer-overflow \
+ -fsanitize=unsigned-integer-overflow \
+ -fsanitize=implicit-signed-integer-truncation \
+ -fsanitize=implicit-unsigned-integer-truncation \
+ -fsanitize-ignorelist=$(srctree)/scripts/integer-wrap-ignore.scl
+export CFLAGS_UBSAN_INTEGER_WRAP := $(ubsan-integer-wrap-cflags-y)