Fix potential TLS-related memory corruption.

Avoid writing to uninitialized TLS as a side effect of deallocation.
Initializing TLS during deallocation is unsafe because it is possible
that a thread never did any allocation, and that TLS has already been
deallocated by the threads library, resulting in write-after-free
corruption.  These fixes affect prof_tdata and quarantine; all other
uses of TLS are already safe, whether intentionally (as for tcache) or
unintentionally (as for arenas).
This commit is contained in:
Jason Evans
2013-01-30 15:03:11 -08:00
parent 83789f4530
commit bbe29d374d
7 changed files with 105 additions and 65 deletions

View File

@@ -1,6 +1,9 @@
/******************************************************************************/
#ifdef JEMALLOC_H_TYPES
typedef struct quarantine_obj_s quarantine_obj_t;
typedef struct quarantine_s quarantine_t;
/* Default per thread quarantine size if valgrind is enabled. */
#define JEMALLOC_VALGRIND_QUARANTINE_DEFAULT (ZU(1) << 24)
@@ -8,17 +11,57 @@
/******************************************************************************/
#ifdef JEMALLOC_H_STRUCTS
struct quarantine_obj_s {
void *ptr;
size_t usize;
};
struct quarantine_s {
size_t curbytes;
size_t curobjs;
size_t first;
#define LG_MAXOBJS_INIT 10
size_t lg_maxobjs;
quarantine_obj_t objs[1]; /* Dynamically sized ring buffer. */
};
#endif /* JEMALLOC_H_STRUCTS */
/******************************************************************************/
#ifdef JEMALLOC_H_EXTERNS
quarantine_t *quarantine_init(size_t lg_maxobjs);
void quarantine(void *ptr);
void quarantine_cleanup(void *arg);
bool quarantine_boot(void);
#endif /* JEMALLOC_H_EXTERNS */
/******************************************************************************/
#ifdef JEMALLOC_H_INLINES
#ifndef JEMALLOC_ENABLE_INLINE
malloc_tsd_protos(JEMALLOC_ATTR(unused), quarantine, quarantine_t *)
void quarantine_alloc_hook(void);
#endif
#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_QUARANTINE_C_))
malloc_tsd_externs(quarantine, quarantine_t *)
malloc_tsd_funcs(JEMALLOC_ALWAYS_INLINE, quarantine, quarantine_t *, NULL,
quarantine_cleanup)
JEMALLOC_ALWAYS_INLINE void
quarantine_alloc_hook(void)
{
quarantine_t *quarantine;
assert(config_fill && opt_quarantine);
quarantine = *quarantine_tsd_get();
if (quarantine == NULL)
quarantine_init(LG_MAXOBJS_INIT);
}
#endif
#endif /* JEMALLOC_H_INLINES */
/******************************************************************************/