Merge pull request #17943 from opensourcerouting/clear-event-cpu-uaf

lib: fix use after free in `clear event cpu`
This commit is contained in:
Russ White 2025-02-04 06:57:52 -05:00 committed by GitHub
commit f9e11d6974
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2 changed files with 19 additions and 11 deletions

View file

@ -111,6 +111,11 @@ static struct cpu_event_history *cpu_records_get(struct event_loop *loop,
return res;
}
static void cpu_records_clear(struct cpu_event_history *p)
{
memset(p->_clear_begin, 0, p->_clear_end - p->_clear_begin);
}
static void cpu_records_free(struct cpu_event_history **p)
{
XFREE(MTYPE_EVENT_STATS, *p);
@ -250,20 +255,15 @@ static void cpu_record_clear(uint8_t filter)
for (ALL_LIST_ELEMENTS_RO(masters, ln, m)) {
frr_with_mutex (&m->mtx) {
struct cpu_event_history *item;
struct cpu_records_head old[1];
cpu_records_init(old);
cpu_records_swap_all(old, m->cpu_records);
while ((item = cpu_records_pop(old))) {
/* it isn't possible to free the memory here
* because some of these will be in use (e.g.
* the one we're currently running in!)
*/
frr_each (cpu_records, m->cpu_records, item) {
if (item->types & filter)
cpu_records_free(&item);
else
cpu_records_add(m->cpu_records,
item);
cpu_records_clear(item);
}
cpu_records_fini(old);
}
}
}

View file

@ -139,6 +139,10 @@ struct cpu_event_history {
struct cpu_records_item item;
void (*func)(struct event *e);
/* fields between the pair of these two are nulled on "clear event cpu" */
char _clear_begin[0];
atomic_size_t total_cpu_warn;
atomic_size_t total_wall_warn;
atomic_size_t total_starv_warn;
@ -149,6 +153,10 @@ struct cpu_event_history {
} real;
struct time_stats cpu;
atomic_uint_fast32_t types;
/* end of cleared region */
char _clear_end[0];
const char *funcname;
};