Commit de553438 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

[S390] Protect against sigaltstack wraparound. 



This is just a port of 83bd0102
"x86: protect against sigaltstack wraparound".

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent 08a8a0c5

arch/s390/kernel/compat_signal.c

+10 −0
Original line number Diff line number Diff line
@@ -428,6 +428,10 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) 
	/* Default to using normal stack */

	sp = (unsigned long) A(regs->gprs[15]);



	/* Overflow on alternate signal stack gives SIGSEGV. */

	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))

		return (void __user *) -1UL;



	/* This is the X/Open sanctioned signal stack switching.  */

	if (ka->sa.sa_flags & SA_ONSTACK) {

		if (! sas_ss_flags(sp))
@@ -461,6 +465,9 @@ static int setup_frame32(int sig, struct k_sigaction *ka, 
	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32)))

		goto give_sigsegv;



	if (frame == (void __user *) -1UL)

		goto give_sigsegv;



	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))

		goto give_sigsegv;
@@ -514,6 +521,9 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info, 
	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32)))

		goto give_sigsegv;



	if (frame == (void __user *) -1UL)

		goto give_sigsegv;



	if (copy_siginfo_to_user32(&frame->info, info))

		goto give_sigsegv;

arch/s390/kernel/signal.c

+10 −0
Original line number Diff line number Diff line
@@ -235,6 +235,10 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) 
	/* Default to using normal stack */

	sp = regs->gprs[15];



	/* Overflow on alternate signal stack gives SIGSEGV. */

	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))

		return (void __user *) -1UL;



	/* This is the X/Open sanctioned signal stack switching.  */

	if (ka->sa.sa_flags & SA_ONSTACK) {

		if (! sas_ss_flags(sp))
@@ -270,6 +274,9 @@ static int setup_frame(int sig, struct k_sigaction *ka, 
	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))

		goto give_sigsegv;



	if (frame == (void __user *) -1UL)

		goto give_sigsegv;



	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))

		goto give_sigsegv;
@@ -327,6 +334,9 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))

		goto give_sigsegv;



	if (frame == (void __user *) -1UL)

		goto give_sigsegv;



	if (copy_siginfo_to_user(&frame->info, info))

		goto give_sigsegv;