sparc64: Fix end-of-stack checking in save_stack_trace().
Bug reported by Alexander Beregalov.
Before we dereference the stack frame or try to peek at the
pt_regs magic value, make sure the entire object is within
the kernel stack bounds.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/stacktrace.c b/arch/sparc64/kernel/stacktrace.c
index b3e3737..e9d7f06 100644
--- a/arch/sparc64/kernel/stacktrace.c
+++ b/arch/sparc64/kernel/stacktrace.c
@@ -26,13 +26,15 @@
/* Bogus frame pointer? */
if (fp < (thread_base + sizeof(struct thread_info)) ||
- fp >= (thread_base + THREAD_SIZE))
+ fp > (thread_base + THREAD_SIZE - sizeof(struct sparc_stackf)))
break;
sf = (struct sparc_stackf *) fp;
regs = (struct pt_regs *) (sf + 1);
- if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC) {
+ if (((unsigned long)regs <=
+ (thread_base + THREAD_SIZE - sizeof(*regs))) &&
+ (regs->magic & ~0x1ff) == PT_REGS_MAGIC) {
if (!(regs->tstate & TSTATE_PRIV))
break;
pc = regs->tpc;