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fix dangling pointers in x32 syscall timespec fixup code 

the lifetime of compound literals is the block in which they appear.
the temporary struct __timespec_kernel objects created as compound
literals no longer existed at the time their addresses were passed to
the kernel.
This commit is contained in:
Rich Felker 2015-05-01 21:22:27 -04:00
parent 7561ac45ed
commit 4f69594689
2 changed files with 23 additions and 10 deletions
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10
arch/x32/src/syscall_cp_fixup.c
View File

@ -9,14 +9,18 @@ long __syscall_cp_internal(volatile void*, long long, long long, long long, long
struct __timespec { long long tv_sec; long tv_nsec; };
struct __timespec_kernel { long long tv_sec; long long tv_nsec; };
#define __tsc(X) ((struct __timespec*)(unsigned long)(X))
#define __fixup(X) do { if(X) X = (unsigned long) (&(struct __timespec_kernel) \
{ .tv_sec = __tsc(X)->tv_sec, .tv_nsec = __tsc(X)->tv_nsec}); } while(0)
#define __fixup(X) do { if(X) { \
ts->tv_sec = __tsc(X)->tv_sec; \
ts->tv_nsec = __tsc(X)->tv_nsec; \
(X) = (unsigned long)ts; } } while(0)
#ifdef SHARED
__attribute__((__visibility__("hidden")))
#endif
long __syscall_cp_asm (volatile void * foo, long long n, long long a1, long long a2, long long a3,
long long a4, long long a5, long long a6) {
long long a4, long long a5, long long a6)
{
struct __timespec_kernel ts[1];
switch (n) {
case SYS_mq_timedsend: case SYS_mq_timedreceive: case SYS_pselect6:
__fixup(a5);

23
arch/x32/syscall_arch.h
View File

@ -6,8 +6,10 @@ typedef long long syscall_arg_t;
struct __timespec { long long tv_sec; long tv_nsec; };
struct __timespec_kernel { long long tv_sec; long long tv_nsec; };
#define __tsc(X) ((struct __timespec*)(unsigned long)(X))
#define __fixup(X) do { if(X) X = (unsigned long) (&(struct __timespec_kernel) \
{ .tv_sec = __tsc(X)->tv_sec, .tv_nsec = __tsc(X)->tv_nsec}); } while(0)
#define __fixup(X) do { if(X) { \
ts->tv_sec = __tsc(X)->tv_sec; \
ts->tv_nsec = __tsc(X)->tv_nsec; \
(X) = (unsigned long)ts; } } while(0)
#define __fixup_case_2 \
case SYS_nanosleep: \
__fixup(a1); break; \
@ -17,10 +19,13 @@ struct __timespec_kernel { long long tv_sec; long long tv_nsec; };
case SYS_clock_nanosleep: case SYS_rt_sigtimedwait: case SYS_ppoll: \
__fixup(a3); break; \
case SYS_utimensat: \
if(a3) a3 = (unsigned long) ((struct __timespec_kernel[2]) { \
[0] = {.tv_sec = __tsc(a3)[0].tv_sec, .tv_nsec = __tsc(a3)[0].tv_nsec}, \
[1] = {.tv_sec = __tsc(a3)[1].tv_sec, .tv_nsec = __tsc(a3)[1].tv_nsec}, \
}); break;
if(a3) { \
ts[0].tv_sec = __tsc(a3)[0].tv_sec; \
ts[0].tv_nsec = __tsc(a3)[0].tv_nsec; \
ts[1].tv_sec = __tsc(a3)[1].tv_sec; \
ts[1].tv_nsec = __tsc(a3)[1].tv_nsec; \
a3 = (unsigned long)ts; \
} break;
#define __fixup_case_4 \
case SYS_futex: \
if((a2 & (~128 /* FUTEX_PRIVATE_FLAG */)) == 0 /* FUTEX_WAIT */) __fixup(a4); break;
@ -45,7 +50,7 @@ static __inline long __syscall1(long long n, long long a1)
static __inline long __syscall2(long long n, long long a1, long long a2)
{
unsigned long ret;
struct __timespec *ts2 = 0;
struct __timespec_kernel ts[1];
switch (n) {
__fixup_case_2;
}
@ -57,6 +62,7 @@ static __inline long __syscall2(long long n, long long a1, long long a2)
static __inline long __syscall3(long long n, long long a1, long long a2, long long a3)
{
unsigned long ret;
struct __timespec_kernel ts[2];
switch (n) {
__fixup_case_2;
__fixup_case_3;
@ -71,6 +77,7 @@ static __inline long __syscall4(long long n, long long a1, long long a2, long lo
{
unsigned long ret;
register long long a4 __asm__("r10") = a4_;
struct __timespec_kernel ts[2];
switch (n) {
__fixup_case_2;
__fixup_case_3;
@ -87,6 +94,7 @@ static __inline long __syscall5(long long n, long long a1, long long a2, long lo
unsigned long ret;
register long long a4 __asm__("r10") = a4_;
register long long a5 __asm__("r8") = a5_;
struct __timespec_kernel ts[2];
switch (n) {
__fixup_case_2;
__fixup_case_3;
@ -105,6 +113,7 @@ static __inline long __syscall6(long long n, long long a1, long long a2, long lo
register long long a4 __asm__("r10") = a4_;
register long long a5 __asm__("r8") = a5_;
register long long a6 __asm__("r9") = a6_;
struct __timespec_kernel ts[2];
switch (n) {
__fixup_case_2;
__fixup_case_3;