Merge branch 'parisc-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc fixes from Helge Deller:

 - Prevent kernel panics by adding proper checking of register values
   injected via the ptrace interface

 - Wire up the new clone3 syscall

* 'parisc-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Wire up clone3 syscall
  parisc: Avoid kernel panic triggered by invalid kprobe
  parisc: Ensure userspace privilege for ptraced processes in regset functions
  parisc: Fix kernel panic due invalid values in IAOQ0 or IAOQ1

5 files changed, 26 insertions, 12 deletions

diff --git a/arch/parisc/include/asm/unistd.h b/arch/parisc/include/asm/unistd.h
index b0838dc4dfee..cd438e4150f6 100644
--- a/arch/parisc/include/asm/unistd.h
+++ b/arch/parisc/include/asm/unistd.h
@@ -166,6 +166,7 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5)	\
 #define __ARCH_WANT_SYS_FORK
 #define __ARCH_WANT_SYS_VFORK
 #define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_CLONE3
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
 
 #ifdef CONFIG_64BIT
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 3e430590c1e1..d9d3387f7c47 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1732,6 +1732,7 @@ ENDPROC_CFI(sys_\name\()_wrapper)
 	.endm
 
 fork_like clone
+fork_like clone3
 fork_like fork
 fork_like vfork
 
diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c
index d58960b33bda..5d7f2692ac5a 100644
--- a/arch/parisc/kernel/kprobes.c
+++ b/arch/parisc/kernel/kprobes.c
@@ -133,6 +133,9 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs)
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 	struct kprobe *p = kprobe_running();
 
+	if (!p)
+		return 0;
+
 	if (regs->iaoq[0] != (unsigned long)p->ainsn.insn+4)
 		return 0;
 
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index f642ba378ffa..9f6ff7bc06f9 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -167,6 +167,9 @@ long arch_ptrace(struct task_struct *child, long request,
 		if ((addr & (sizeof(unsigned long)-1)) ||
 		     addr >= sizeof(struct pt_regs))
 			break;
+		if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
+			data |= 3; /* ensure userspace privilege */
+		}
 		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
 				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
 				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
@@ -228,16 +231,18 @@ long arch_ptrace(struct task_struct *child, long request,
 
 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
 {
-	if (offset < 0)
-		return sizeof(struct pt_regs);
-	else if (offset <= 32*4)	/* gr[0..31] */
-		return offset * 2 + 4;
-	else if (offset <= 32*4+32*8)	/* gr[0..31] + fr[0..31] */
-		return offset + 32*4;
-	else if (offset < sizeof(struct pt_regs)/2 + 32*4)
-		return offset * 2 + 4 - 32*8;
+	compat_ulong_t pos;
+
+	if (offset < 32*4)	/* gr[0..31] */
+		pos = offset * 2 + 4;
+	else if (offset < 32*4+32*8)	/* fr[0] ... fr[31] */
+		pos = (offset - 32*4) + PT_FR0;
+	else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
+		pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
 	else
-		return sizeof(struct pt_regs);
+		pos = sizeof(struct pt_regs);
+
+	return pos;
 }
 
 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
@@ -281,9 +286,12 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 			addr = translate_usr_offset(addr);
 			if (addr >= sizeof(struct pt_regs))
 				break;
+			if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
+				data |= 3; /* ensure userspace privilege */
+			}
 			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 				/* Special case, fp regs are 64 bits anyway */
-				*(__u64 *) ((char *) task_regs(child) + addr) = data;
+				*(__u32 *) ((char *) task_regs(child) + addr) = data;
 				ret = 0;
 			}
 			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
@@ -496,7 +504,8 @@ static void set_reg(struct pt_regs *regs, int num, unsigned long val)
 			return;
 	case RI(iaoq[0]):
 	case RI(iaoq[1]):
-			regs->iaoq[num - RI(iaoq[0])] = val;
+			/* set 2 lowest bits to ensure userspace privilege: */
+			regs->iaoq[num - RI(iaoq[0])] = val | 3;
 			return;
 	case RI(sar):	regs->sar = val;
 			return;
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c7aadfef5386..670d1371aca1 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -431,4 +431,4 @@
 432	common	fsmount				sys_fsmount
 433	common	fspick				sys_fspick
 434	common	pidfd_open			sys_pidfd_open
-# 435 reserved for clone3
+435	common	clone3				sys_clone3_wrapper