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 --- drivers/accessibility/speakup/utils.h | 102 ++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/accessibility/speakup/utils.h (limited to 'drivers/accessibility/speakup/utils.h') diff --git a/drivers/accessibility/speakup/utils.h b/drivers/accessibility/speakup/utils.h new file mode 100644 index 000000000..4ce9a12f7 --- /dev/null +++ b/drivers/accessibility/speakup/utils.h @@ -0,0 +1,102 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* utils.h + * originally written by: Kirk Reiser. + * + ** Copyright (C) 2002 Kirk Reiser. + * Copyright (C) 2003 David Borowski. + */ + +#include + +#define MAXKEYS 512 +#define MAXKEYVAL 160 +#define HASHSIZE 101 +#define is_shift -3 +#define is_spk -2 +#define is_input -1 + +struct st_key { + char *name; + struct st_key *next; + int value, shift; +}; + +struct st_key key_table[MAXKEYS]; +struct st_key *extra_keys = key_table+HASHSIZE; +char *def_name, *def_val; +FILE *infile; +int lc; + +char filename[256]; + +static inline void open_input(const char *dir_name, const char *name) +{ + if (dir_name) + snprintf(filename, sizeof(filename), "%s/%s", dir_name, name); + else + snprintf(filename, sizeof(filename), "%s", name); + infile = fopen(filename, "r"); + if (infile == 0) { + fprintf(stderr, "can't open %s\n", filename); + exit(1); + } + lc = 0; +} + +static inline int oops(const char *msg, const char *info) +{ + if (info == NULL) + info = ""; + fprintf(stderr, "error: file %s line %d\n", filename, lc); + fprintf(stderr, "%s %s\n", msg, info); + exit(1); +} + +static inline struct st_key *hash_name(char *name) +{ + unsigned char *pn = (unsigned char *)name; + int hash = 0; + + while (*pn) { + hash = (hash * 17) & 0xfffffff; + if (isupper(*pn)) + *pn = tolower(*pn); + hash += (int)*pn; + pn++; + } + hash %= HASHSIZE; + return &key_table[hash]; +} + +static inline struct st_key *find_key(char *name) +{ + struct st_key *this = hash_name(name); + + while (this) { + if (this->name && !strcmp(name, this->name)) + return this; + this = this->next; + } + return this; +} + +static inline struct st_key *add_key(char *name, int value, int shift) +{ + struct st_key *this = hash_name(name); + + if (extra_keys-key_table >= MAXKEYS) + oops("out of key table space, enlarge MAXKEYS", NULL); + if (this->name != NULL) { + while (this->next) { + if (!strcmp(name, this->name)) + oops("attempt to add duplicate key", name); + this = this->next; + } + this->next = extra_keys++; + this = this->next; + } + this->name = strdup(name); + this->value = value; + this->shift = shift; + return this; +} -- cgit v1.3.1