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/stat.h | 73 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 include/uapi/asm-generic/stat.h (limited to 'include/uapi/asm-generic/stat.h') diff --git a/include/uapi/asm-generic/stat.h b/include/uapi/asm-generic/stat.h new file mode 100644 index 000000000..0d962ecd1 --- /dev/null +++ b/include/uapi/asm-generic/stat.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_STAT_H +#define __ASM_GENERIC_STAT_H + +/* + * Everybody gets this wrong and has to stick with it for all + * eternity. Hopefully, this version gets used by new architectures + * so they don't fall into the same traps. + * + * stat64 is copied from powerpc64, with explicit padding added. + * stat is the same structure layout on 64-bit, without the 'long long' + * types. + * + * By convention, 64 bit architectures use the stat interface, while + * 32 bit architectures use the stat64 interface. Note that we don't + * provide an __old_kernel_stat here, which new architecture should + * not have to start with. + */ + +#include + +#define STAT_HAVE_NSEC 1 + +struct stat { + unsigned long st_dev; /* Device. */ + unsigned long st_ino; /* File serial number. */ + unsigned int st_mode; /* File mode. */ + unsigned int st_nlink; /* Link count. */ + unsigned int st_uid; /* User ID of the file's owner. */ + unsigned int st_gid; /* Group ID of the file's group. */ + unsigned long st_rdev; /* Device number, if device. */ + unsigned long __pad1; + long st_size; /* Size of file, in bytes. */ + int st_blksize; /* Optimal block size for I/O. */ + int __pad2; + long st_blocks; /* Number 512-byte blocks allocated. */ + long st_atime; /* Time of last access. */ + unsigned long st_atime_nsec; + long st_mtime; /* Time of last modification. */ + unsigned long st_mtime_nsec; + long st_ctime; /* Time of last status change. */ + unsigned long st_ctime_nsec; + unsigned int __unused4; + unsigned int __unused5; +}; + +/* This matches struct stat64 in glibc2.1. Only used for 32 bit. */ +#if __BITS_PER_LONG != 64 || defined(__ARCH_WANT_STAT64) +struct stat64 { + unsigned long long st_dev; /* Device. */ + unsigned long long st_ino; /* File serial number. */ + unsigned int st_mode; /* File mode. */ + unsigned int st_nlink; /* Link count. */ + unsigned int st_uid; /* User ID of the file's owner. */ + unsigned int st_gid; /* Group ID of the file's group. */ + unsigned long long st_rdev; /* Device number, if device. */ + unsigned long long __pad1; + long long st_size; /* Size of file, in bytes. */ + int st_blksize; /* Optimal block size for I/O. */ + int __pad2; + long long st_blocks; /* Number 512-byte blocks allocated. */ + int st_atime; /* Time of last access. */ + unsigned int st_atime_nsec; + int st_mtime; /* Time of last modification. */ + unsigned int st_mtime_nsec; + int st_ctime; /* Time of last status change. */ + unsigned int st_ctime_nsec; + unsigned int __unused4; + unsigned int __unused5; +}; +#endif + +#endif /* __ASM_GENERIC_STAT_H */ -- cgit v1.3.1