Fix tracing compat binaries on big endian systems.

We need to swap the order of the two 32-bit addresses for big-endian.
This commit is contained in:
Todd C. Miller
2022-05-11 20:07:59 -06:00
parent 31e8506c82
commit 55f5e389ba

View File

@@ -34,6 +34,15 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if defined(HAVE_ENDIAN_H)
# include <endian.h>
#elif defined(HAVE_SYS_ENDIAN_H)
# include <sys/endian.h>
#elif defined(HAVE_MACHINE_ENDIAN_H)
# include <machine/endian.h>
#else
# include "compat/endian.h"
#endif
#include "sudo.h"
#include "sudo_exec.h"
@@ -343,7 +352,10 @@ static size_t
ptrace_read_vec(pid_t pid, struct sudo_ptrace_regs *regs, unsigned long addr,
char **vec, char *buf, size_t bufsize)
{
unsigned long word, next_word = -1;
# ifdef SECCOMP_AUDIT_ARCH_COMPAT
unsigned long next_word = -1;
# endif
unsigned long word;
char *buf0 = buf;
int len = 0;
size_t slen;
@@ -351,18 +363,27 @@ ptrace_read_vec(pid_t pid, struct sudo_ptrace_regs *regs, unsigned long addr,
/* Fill in vector. */
for (;;) {
# ifdef SECCOMP_AUDIT_ARCH_COMPAT
if (next_word == (unsigned long)-1) {
word = ptrace(PTRACE_PEEKDATA, pid, addr, NULL);
if (regs->compat) {
/* Stash the next compat word in next_word. */
# if BYTE_ORDER == BIG_ENDIAN
next_word = word & 0xffffffffU;
word >>= 32;
# else
next_word = word >> 32;
word &= 0xffffffffU;
# endif
}
} else {
/* Use the stashed value of the next word. */
word = next_word;
next_word = (unsigned long)-1;
}
# else /* SECCOMP_AUDIT_ARCH_COMPAT */
word = ptrace(PTRACE_PEEKDATA, pid, addr, NULL);
# endif /* SECCOMP_AUDIT_ARCH_COMPAT */
switch (word) {
case -1:
sudo_warn("%s: ptrace(PTRACE_PEEKDATA, %d, 0x%lx, NULL)",
@@ -396,23 +417,35 @@ bad:
static int
ptrace_get_vec_len(pid_t pid, struct sudo_ptrace_regs *regs, unsigned long addr)
{
unsigned long word, next_word = -1;
# ifdef SECCOMP_AUDIT_ARCH_COMPAT
unsigned long next_word = -1;
# endif
unsigned long word;
int len = 0;
debug_decl(ptrace_get_vec_len, SUDO_DEBUG_EXEC);
for (;;) {
# ifdef SECCOMP_AUDIT_ARCH_COMPAT
if (next_word == (unsigned long)-1) {
word = ptrace(PTRACE_PEEKDATA, pid, addr, NULL);
if (regs->compat) {
/* Stash the next compat word in next_word. */
# if BYTE_ORDER == BIG_ENDIAN
next_word = word & 0xffffffffU;
word >>= 32;
# else
next_word = word >> 32;
word &= 0xffffffffU;
# endif
}
} else {
/* Use the stashed value of the next word. */
word = next_word;
next_word = (unsigned long)-1;
}
# else /* SECCOMP_AUDIT_ARCH_COMPAT */
word = ptrace(PTRACE_PEEKDATA, pid, addr, NULL);
# endif /* SECCOMP_AUDIT_ARCH_COMPAT */
switch (word) {
case -1:
sudo_warn("%s: ptrace(PTRACE_PEEKDATA, %d, 0x%lx, NULL)",
@@ -966,10 +999,15 @@ ptrace_intercept_execve(pid_t pid, struct intercept_closure *closure)
/* Copy new argv (+ NULL) into tracee one word at a time. */
for (i = 0; i < argc; i++) {
/* Store string address as new argv[i]. */
if (ptrace(PTRACE_POKEDATA, pid, sp, strtab) == -1) {
unsigned long word = strtab;
# if defined(SECCOMP_AUDIT_ARCH_COMPAT) && BYTE_ORDER == BIG_ENDIAN
if (regs.compat)
word <<= 32;
# endif
if (ptrace(PTRACE_POKEDATA, pid, sp, word) == -1) {
sudo_warn(
"%s: ptrace(PTRACE_POKEDATA, %d, 0x%lx, 0x%lx)",
__func__, (int)pid, sp, strtab);
__func__, (int)pid, sp, word);
goto done;
}
sp += regs.wordsize;