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Diffstat (limited to 'arch/s390/kernel/compat_signal.c')
-rw-r--r--arch/s390/kernel/compat_signal.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index a5692c460ba..c7f02e777af 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;