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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-04 10:43:19 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 07:58:36 -0700 |
| commit | 6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch) | |
| tree | 58e8288fead484f6755ad0815fc74c3742663761 /tools/verification/models/rtapp | |
| download | linux-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 'tools/verification/models/rtapp')
| -rw-r--r-- | tools/verification/models/rtapp/pagefault.ltl | 1 | ||||
| -rw-r--r-- | tools/verification/models/rtapp/sleep.ltl | 20 | ||||
| -rw-r--r-- | tools/verification/models/rtapp/wakeup.ltl | 5 |
3 files changed, 26 insertions, 0 deletions
diff --git a/tools/verification/models/rtapp/pagefault.ltl b/tools/verification/models/rtapp/pagefault.ltl new file mode 100644 index 000000000..d7ce62102 --- /dev/null +++ b/tools/verification/models/rtapp/pagefault.ltl @@ -0,0 +1 @@ +RULE = always (RT imply not PAGEFAULT) diff --git a/tools/verification/models/rtapp/sleep.ltl b/tools/verification/models/rtapp/sleep.ltl new file mode 100644 index 000000000..4d78fdd20 --- /dev/null +++ b/tools/verification/models/rtapp/sleep.ltl @@ -0,0 +1,20 @@ +RULE = always ((RT and SLEEP and USER_THREAD) imply (RT_FRIENDLY_SLEEP or ALLOWLIST)) + +RT_FRIENDLY_SLEEP = RT_VALID_SLEEP_REASON + and ((not SCHEDULE_IN) until RT_FRIENDLY_WAKE) + +RT_VALID_SLEEP_REASON = FUTEX_WAIT + or RT_FRIENDLY_NANOSLEEP + or EPOLL_WAIT + +RT_FRIENDLY_NANOSLEEP = CLOCK_NANOSLEEP + and NANOSLEEP_TIMER_ABSTIME + and not NANOSLEEP_CLOCK_REALTIME + +RT_FRIENDLY_WAKE = WOKEN_BY_EQUAL_OR_HIGHER_PRIO + or WOKEN_BY_HARDIRQ + or WOKEN_BY_NMI + or ABORT_SLEEP + +ALLOWLIST = BLOCK_ON_RT_MUTEX + or FUTEX_LOCK_PI diff --git a/tools/verification/models/rtapp/wakeup.ltl b/tools/verification/models/rtapp/wakeup.ltl new file mode 100644 index 000000000..a5d63ca08 --- /dev/null +++ b/tools/verification/models/rtapp/wakeup.ltl @@ -0,0 +1,5 @@ +RULE = always (((RT and USER_THREAD) imply + (not (WOKEN_BY_LOWER_PRIO or WOKEN_BY_SOFTIRQ)) or ALLOWLIST)) + +ALLOWLIST = BLOCK_ON_RT_MUTEX + or FUTEX_LOCK_PI |