1 files changed, 11 insertions, 0 deletions

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index a5692c460bad..c7f02e777af2 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -29,6 +29,7 @@
 #include <asm/lowcore.h>
 #include "compat_linux.h"
 #include "compat_ptrace.h"
+#include "entry.h"
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
@@ -428,6 +429,10 @@ 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 +466,9 @@ 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 +522,9 @@ 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;