freebsd-skq/sys/i386/ibcs2/ibcs2_signal.c
Tim J. Robbins a95edcba94 Fix a multitude of security bugs in the iBCS2 emulator:
- Return NULL instead of returning memory outside of the stackgap
  in stackgap_alloc() (FreeBSD-SA-00:42.linux)
- Check for stackgap_alloc() returning NULL in ibcs2_emul_find();
  other calls to stackgap_alloc() have not been changed since they
  are small fixed-size allocations.
- Replace use of strcpy() with strlcpy() in exec_coff_imgact()
  to avoid buffer overflow
- Use strlcat() instead of strcat() to avoid a one byte buffer
  overflow in ibcs2_setipdomainname()
- Use copyinstr() instead of copyin() in ibcs2_setipdomainname()
  to ensure that the string is null-terminated
- Avoid integer overflow in ibcs2_setgroups() and ibcs2_setgroups()
  by checking that gidsetsize argument is non-negative and
  no larger than NGROUPS_MAX.
- Range-check signal numbers in ibcs2_wait(), ibcs2_sigaction(),
  ibcs2_sigsys() and ibcs2_kill() to avoid accessing array past
  the end (or before the start)
2003-10-12 04:25:26 +00:00

442 lines
10 KiB
C

/*
* Copyright (c) 1995 Scott Bartram
* Copyright (c) 1995 Steven Wallace
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/signalvar.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <i386/ibcs2/ibcs2_types.h>
#include <i386/ibcs2/ibcs2_signal.h>
#include <i386/ibcs2/ibcs2_proto.h>
#include <i386/ibcs2/ibcs2_xenix.h>
#include <i386/ibcs2/ibcs2_util.h>
#define sigemptyset(s) SIGEMPTYSET(*(s))
#define sigismember(s, n) SIGISMEMBER(*(s), n)
#define sigaddset(s, n) SIGADDSET(*(s), n)
#define ibcs2_sigmask(n) (1 << ((n) - 1))
#define ibcs2_sigemptyset(s) bzero((s), sizeof(*(s)))
#define ibcs2_sigismember(s, n) (*(s) & ibcs2_sigmask(n))
#define ibcs2_sigaddset(s, n) (*(s) |= ibcs2_sigmask(n))
static void ibcs2_to_bsd_sigset(const ibcs2_sigset_t *, sigset_t *);
static void bsd_to_ibcs2_sigset(const sigset_t *, ibcs2_sigset_t *);
static void ibcs2_to_bsd_sigaction(struct ibcs2_sigaction *,
struct sigaction *);
static void bsd_to_ibcs2_sigaction(struct sigaction *,
struct ibcs2_sigaction *);
int bsd_to_ibcs2_sig[IBCS2_SIGTBLSZ] = {
IBCS2_SIGHUP, /* 1 */
IBCS2_SIGINT, /* 2 */
IBCS2_SIGQUIT, /* 3 */
IBCS2_SIGILL, /* 4 */
IBCS2_SIGTRAP, /* 5 */
IBCS2_SIGABRT, /* 6 */
IBCS2_SIGEMT, /* 7 */
IBCS2_SIGFPE, /* 8 */
IBCS2_SIGKILL, /* 9 */
IBCS2_SIGBUS, /* 10 */
IBCS2_SIGSEGV, /* 11 */
IBCS2_SIGSYS, /* 12 */
IBCS2_SIGPIPE, /* 13 */
IBCS2_SIGALRM, /* 14 */
IBCS2_SIGTERM, /* 15 */
0, /* 16 - SIGURG */
IBCS2_SIGSTOP, /* 17 */
IBCS2_SIGTSTP, /* 18 */
IBCS2_SIGCONT, /* 19 */
IBCS2_SIGCLD, /* 20 */
IBCS2_SIGTTIN, /* 21 */
IBCS2_SIGTTOU, /* 22 */
IBCS2_SIGPOLL, /* 23 */
0, /* 24 - SIGXCPU */
0, /* 25 - SIGXFSZ */
IBCS2_SIGVTALRM, /* 26 */
IBCS2_SIGPROF, /* 27 */
IBCS2_SIGWINCH, /* 28 */
0, /* 29 */
IBCS2_SIGUSR1, /* 30 */
IBCS2_SIGUSR2, /* 31 */
0 /* 32 */
};
static int ibcs2_to_bsd_sig[IBCS2_SIGTBLSZ] = {
SIGHUP, /* 1 */
SIGINT, /* 2 */
SIGQUIT, /* 3 */
SIGILL, /* 4 */
SIGTRAP, /* 5 */
SIGABRT, /* 6 */
SIGEMT, /* 7 */
SIGFPE, /* 8 */
SIGKILL, /* 9 */
SIGBUS, /* 10 */
SIGSEGV, /* 11 */
SIGSYS, /* 12 */
SIGPIPE, /* 13 */
SIGALRM, /* 14 */
SIGTERM, /* 15 */
SIGUSR1, /* 16 */
SIGUSR2, /* 17 */
SIGCHLD, /* 18 */
0, /* 19 - SIGPWR */
SIGWINCH, /* 20 */
0, /* 21 */
SIGIO, /* 22 */
SIGSTOP, /* 23 */
SIGTSTP, /* 24 */
SIGCONT, /* 25 */
SIGTTIN, /* 26 */
SIGTTOU, /* 27 */
SIGVTALRM, /* 28 */
SIGPROF, /* 29 */
0, /* 30 */
0, /* 31 */
0 /* 32 */
};
void
ibcs2_to_bsd_sigset(iss, bss)
const ibcs2_sigset_t *iss;
sigset_t *bss;
{
int i, newsig;
sigemptyset(bss);
for (i = 1; i <= IBCS2_SIGTBLSZ; i++) {
if (ibcs2_sigismember(iss, i)) {
newsig = ibcs2_to_bsd_sig[_SIG_IDX(i)];
if (newsig)
sigaddset(bss, newsig);
}
}
}
static void
bsd_to_ibcs2_sigset(bss, iss)
const sigset_t *bss;
ibcs2_sigset_t *iss;
{
int i, newsig;
ibcs2_sigemptyset(iss);
for (i = 1; i <= IBCS2_SIGTBLSZ; i++) {
if (sigismember(bss, i)) {
newsig = bsd_to_ibcs2_sig[_SIG_IDX(i)];
if (newsig)
ibcs2_sigaddset(iss, newsig);
}
}
}
static void
ibcs2_to_bsd_sigaction(isa, bsa)
struct ibcs2_sigaction *isa;
struct sigaction *bsa;
{
bsa->sa_handler = isa->isa_handler;
ibcs2_to_bsd_sigset(&isa->isa_mask, &bsa->sa_mask);
bsa->sa_flags = 0; /* ??? SA_NODEFER */
if ((isa->isa_flags & IBCS2_SA_NOCLDSTOP) != 0)
bsa->sa_flags |= SA_NOCLDSTOP;
}
static void
bsd_to_ibcs2_sigaction(bsa, isa)
struct sigaction *bsa;
struct ibcs2_sigaction *isa;
{
isa->isa_handler = bsa->sa_handler;
bsd_to_ibcs2_sigset(&bsa->sa_mask, &isa->isa_mask);
isa->isa_flags = 0;
if ((bsa->sa_flags & SA_NOCLDSTOP) != 0)
isa->isa_flags |= IBCS2_SA_NOCLDSTOP;
}
int
ibcs2_sigaction(td, uap)
register struct thread *td;
struct ibcs2_sigaction_args *uap;
{
struct ibcs2_sigaction isa;
struct sigaction nbsa, obsa;
struct sigaction *nbsap;
int error;
if (uap->act != NULL) {
if ((error = copyin(uap->act, &isa, sizeof(isa))) != 0)
return (error);
ibcs2_to_bsd_sigaction(&isa, &nbsa);
nbsap = &nbsa;
} else
nbsap = NULL;
if (uap->sig <= 0 || uap->sig > IBCS2_NSIG)
return (EINVAL);
error = kern_sigaction(td, ibcs2_to_bsd_sig[_SIG_IDX(uap->sig)], &nbsa,
&obsa, 0);
if (error == 0 && uap->oact != NULL) {
bsd_to_ibcs2_sigaction(&obsa, &isa);
error = copyout(&isa, uap->oact, sizeof(isa));
}
return (error);
}
int
ibcs2_sigsys(td, uap)
register struct thread *td;
struct ibcs2_sigsys_args *uap;
{
struct proc *p = td->td_proc;
struct sigaction sa;
int signum = IBCS2_SIGNO(uap->sig);
int error;
if (signum <= 0 || signum > IBCS2_NSIG) {
if (IBCS2_SIGCALL(uap->sig) == IBCS2_SIGNAL_MASK ||
IBCS2_SIGCALL(uap->sig) == IBCS2_SIGSET_MASK)
td->td_retval[0] = (int)IBCS2_SIG_ERR;
return EINVAL;
}
signum = ibcs2_to_bsd_sig[_SIG_IDX(signum)];
switch (IBCS2_SIGCALL(uap->sig)) {
case IBCS2_SIGSET_MASK:
/*
* Check for SIG_HOLD action.
* Otherwise, perform signal() except with different sa_flags.
*/
if (uap->fp != IBCS2_SIG_HOLD) {
/* add sig to mask before exececuting signal handler */
sa.sa_flags = 0;
goto ibcs2_sigset;
}
/* else FALLTHROUGH to sighold */
case IBCS2_SIGHOLD_MASK:
{
sigset_t mask;
SIGEMPTYSET(mask);
SIGADDSET(mask, signum);
return (kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
0));
}
case IBCS2_SIGNAL_MASK:
{
struct sigaction osa;
/* do not automatically block signal */
sa.sa_flags = SA_NODEFER;
#ifdef SA_RESETHAND
if((signum != IBCS2_SIGILL) &&
(signum != IBCS2_SIGTRAP) &&
(signum != IBCS2_SIGPWR))
/* set to SIG_DFL before executing handler */
sa.sa_flags |= SA_RESETHAND;
#endif
ibcs2_sigset:
sa.sa_handler = uap->fp;
sigemptyset(&sa.sa_mask);
#if 0
if (signum != SIGALRM)
sa.sa_flags |= SA_RESTART;
#endif
error = kern_sigaction(td, signum, &sa, &osa, 0);
if (error != 0) {
DPRINTF(("signal: sigaction failed: %d\n",
error));
td->td_retval[0] = (int)IBCS2_SIG_ERR;
return (error);
}
td->td_retval[0] = (int)osa.sa_handler;
/* special sigset() check */
if(IBCS2_SIGCALL(uap->sig) == IBCS2_SIGSET_MASK) {
PROC_LOCK(p);
/* check to make sure signal is not blocked */
if(sigismember(&td->td_sigmask, signum)) {
/* return SIG_HOLD and unblock signal*/
td->td_retval[0] = (int)IBCS2_SIG_HOLD;
SIGDELSET(td->td_sigmask, signum);
signotify(td);
}
PROC_UNLOCK(p);
}
return 0;
}
case IBCS2_SIGRELSE_MASK:
{
sigset_t mask;
SIGEMPTYSET(mask);
SIGADDSET(mask, signum);
return (kern_sigprocmask(td, SIG_UNBLOCK, &mask, NULL,
0));
}
case IBCS2_SIGIGNORE_MASK:
{
sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
error = kern_sigaction(td, signum, &sa, NULL, 0);
if (error != 0)
DPRINTF(("sigignore: sigaction failed\n"));
return (error);
}
case IBCS2_SIGPAUSE_MASK:
{
sigset_t mask;
PROC_LOCK(p);
mask = td->td_sigmask;
PROC_UNLOCK(p);
SIGDELSET(mask, signum);
return kern_sigsuspend(td, mask);
}
default:
return ENOSYS;
}
}
int
ibcs2_sigprocmask(td, uap)
register struct thread *td;
struct ibcs2_sigprocmask_args *uap;
{
ibcs2_sigset_t iss;
sigset_t oss, nss;
sigset_t *nssp;
int error, how;
switch (uap->how) {
case IBCS2_SIG_BLOCK:
how = SIG_BLOCK;
break;
case IBCS2_SIG_UNBLOCK:
how = SIG_UNBLOCK;
break;
case IBCS2_SIG_SETMASK:
how = SIG_SETMASK;
break;
default:
return (EINVAL);
}
if (uap->set != NULL) {
if ((error = copyin(uap->set, &iss, sizeof(iss))) != 0)
return error;
ibcs2_to_bsd_sigset(&iss, &nss);
nssp = &nss;
} else
nssp = NULL;
error = kern_sigprocmask(td, how, nssp, &oss, 0);
if (error == 0 && uap->oset != NULL) {
bsd_to_ibcs2_sigset(&oss, &iss);
error = copyout(&iss, uap->oset, sizeof(iss));
}
return (error);
}
int
ibcs2_sigpending(td, uap)
register struct thread *td;
struct ibcs2_sigpending_args *uap;
{
struct proc *p = td->td_proc;
sigset_t bss;
ibcs2_sigset_t iss;
PROC_LOCK(p);
bss = td->td_siglist;
SIGSETOR(bss, p->p_siglist);
SIGSETAND(bss, td->td_sigmask);
PROC_UNLOCK(p);
bsd_to_ibcs2_sigset(&bss, &iss);
return copyout(&iss, uap->mask, sizeof(iss));
}
int
ibcs2_sigsuspend(td, uap)
register struct thread *td;
struct ibcs2_sigsuspend_args *uap;
{
ibcs2_sigset_t sss;
sigset_t bss;
int error;
if ((error = copyin(uap->mask, &sss, sizeof(sss))) != 0)
return error;
ibcs2_to_bsd_sigset(&sss, &bss);
return kern_sigsuspend(td, bss);
}
int
ibcs2_pause(td, uap)
register struct thread *td;
struct ibcs2_pause_args *uap;
{
sigset_t mask;
PROC_LOCK(td->td_proc);
mask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
return kern_sigsuspend(td, mask);
}
int
ibcs2_kill(td, uap)
register struct thread *td;
struct ibcs2_kill_args *uap;
{
struct kill_args ka;
if (uap->signo <= 0 || uap->signo > IBCS2_NSIG)
return (EINVAL);
ka.pid = uap->pid;
ka.signum = ibcs2_to_bsd_sig[_SIG_IDX(uap->signo)];
return kill(td, &ka);
}