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 --- fs/jfs/jfs_unicode.h | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 fs/jfs/jfs_unicode.h (limited to 'fs/jfs/jfs_unicode.h') diff --git a/fs/jfs/jfs_unicode.h b/fs/jfs/jfs_unicode.h new file mode 100644 index 000000000..b6a78d4ae --- /dev/null +++ b/fs/jfs/jfs_unicode.h @@ -0,0 +1,136 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) International Business Machines Corp., 2000-2002 + * Portions Copyright (C) Christoph Hellwig, 2001-2002 + */ +#ifndef _H_JFS_UNICODE +#define _H_JFS_UNICODE + +#include +#include +#include "../nls/nls_ucs2_data.h" +#include "jfs_types.h" + +extern int get_UCSname(struct component_name *, struct dentry *); +extern int jfs_strfromUCS_le(char *, const __le16 *, int, struct nls_table *); + +#define free_UCSname(COMP) kfree((COMP)->name) + +/* + * UniStrcpy: Copy a string + */ +static inline wchar_t *UniStrcpy(wchar_t * ucs1, const wchar_t * ucs2) +{ + wchar_t *anchor = ucs1; /* save the start of result string */ + + while ((*ucs1++ = *ucs2++)); + return anchor; +} + + + +/* + * UniStrncpy: Copy length limited string with pad + */ +static inline __le16 *UniStrncpy_le(__le16 * ucs1, const __le16 * ucs2, + size_t n) +{ + __le16 *anchor = ucs1; + + while (n-- && *ucs2) /* Copy the strings */ + *ucs1++ = *ucs2++; + + n++; + while (n--) /* Pad with nulls */ + *ucs1++ = 0; + return anchor; +} + +/* + * UniStrncmp_le: Compare length limited string - native to little-endian + */ +static inline int UniStrncmp_le(const wchar_t * ucs1, const __le16 * ucs2, + size_t n) +{ + if (!n) + return 0; /* Null strings are equal */ + while ((*ucs1 == __le16_to_cpu(*ucs2)) && *ucs1 && --n) { + ucs1++; + ucs2++; + } + return (int) *ucs1 - (int) __le16_to_cpu(*ucs2); +} + +/* + * UniStrncpy_to_le: Copy length limited string with pad to little-endian + */ +static inline __le16 *UniStrncpy_to_le(__le16 * ucs1, const wchar_t * ucs2, + size_t n) +{ + __le16 *anchor = ucs1; + + while (n-- && *ucs2) /* Copy the strings */ + *ucs1++ = cpu_to_le16(*ucs2++); + + n++; + while (n--) /* Pad with nulls */ + *ucs1++ = 0; + return anchor; +} + +/* + * UniStrncpy_from_le: Copy length limited string with pad from little-endian + */ +static inline wchar_t *UniStrncpy_from_le(wchar_t * ucs1, const __le16 * ucs2, + size_t n) +{ + wchar_t *anchor = ucs1; + + while (n-- && *ucs2) /* Copy the strings */ + *ucs1++ = __le16_to_cpu(*ucs2++); + + n++; + while (n--) /* Pad with nulls */ + *ucs1++ = 0; + return anchor; +} + +/* + * UniToupper: Convert a unicode character to upper case + */ +static inline wchar_t UniToupper(wchar_t uc) +{ + const struct UniCaseRange *rp; + + if (uc < sizeof(NlsUniUpperTable)) { /* Latin characters */ + return uc + NlsUniUpperTable[uc]; /* Use base tables */ + } else { + rp = NlsUniUpperRange; /* Use range tables */ + while (rp->start) { + if (uc < rp->start) /* Before start of range */ + return uc; /* Uppercase = input */ + if (uc <= rp->end) /* In range */ + return uc + rp->table[uc - rp->start]; + rp++; /* Try next range */ + } + } + return uc; /* Past last range */ +} + + +/* + * UniStrupr: Upper case a unicode string + */ +static inline wchar_t *UniStrupr(wchar_t * upin) +{ + wchar_t *up; + + up = upin; + while (*up) { /* For all characters */ + *up = UniToupper(*up); + up++; + } + return upin; /* Return input pointer */ +} + +#endif /* !_H_JFS_UNICODE */ -- cgit v1.3.1