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 --- include/uapi/asm-generic/resource.h | 62 +++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/uapi/asm-generic/resource.h (limited to 'include/uapi/asm-generic/resource.h') diff --git a/include/uapi/asm-generic/resource.h b/include/uapi/asm-generic/resource.h new file mode 100644 index 000000000..f12db7a0d --- /dev/null +++ b/include/uapi/asm-generic/resource.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI_ASM_GENERIC_RESOURCE_H +#define _UAPI_ASM_GENERIC_RESOURCE_H + +/* + * Resource limit IDs + * + * ( Compatibility detail: there are architectures that have + * a different rlimit ID order in the 5-9 range and want + * to keep that order for binary compatibility. The reasons + * are historic and all new rlimits are identical across all + * arches. If an arch has such special order for some rlimits + * then it defines them prior including asm-generic/resource.h. ) + */ + +#define RLIMIT_CPU 0 /* CPU time in sec */ +#define RLIMIT_FSIZE 1 /* Maximum filesize */ +#define RLIMIT_DATA 2 /* max data size */ +#define RLIMIT_STACK 3 /* max stack size */ +#define RLIMIT_CORE 4 /* max core file size */ + +#ifndef RLIMIT_RSS +# define RLIMIT_RSS 5 /* max resident set size */ +#endif + +#ifndef RLIMIT_NPROC +# define RLIMIT_NPROC 6 /* max number of processes */ +#endif + +#ifndef RLIMIT_NOFILE +# define RLIMIT_NOFILE 7 /* max number of open files */ +#endif + +#ifndef RLIMIT_MEMLOCK +# define RLIMIT_MEMLOCK 8 /* max locked-in-memory address space */ +#endif + +#ifndef RLIMIT_AS +# define RLIMIT_AS 9 /* address space limit */ +#endif + +#define RLIMIT_LOCKS 10 /* maximum file locks held */ +#define RLIMIT_SIGPENDING 11 /* max number of pending signals */ +#define RLIMIT_MSGQUEUE 12 /* maximum bytes in POSIX mqueues */ +#define RLIMIT_NICE 13 /* max nice prio allowed to raise to + 0-39 for nice level 19 .. -20 */ +#define RLIMIT_RTPRIO 14 /* maximum realtime priority */ +#define RLIMIT_RTTIME 15 /* timeout for RT tasks in us */ +#define RLIM_NLIMITS 16 + +/* + * SuS says limits have to be unsigned. + * Which makes a ton more sense anyway. + * + * Some architectures override this (for compatibility reasons): + */ +#ifndef RLIM_INFINITY +# define RLIM_INFINITY (~0UL) +#endif + + +#endif /* _UAPI_ASM_GENERIC_RESOURCE_H */ -- cgit v1.3.1