Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull rseq fixes from Ingo Molnar:
 "Various rseq ABI fixes and cleanups: use get_user()/put_user(),
  validate parameters and use proper uapi types, etc"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: cleanup: Update comment above rseq_prepare_unload
  rseq: Remove unused types_32_64.h uapi header
  rseq: uapi: Declare rseq_cs field as union, update includes
  rseq: uapi: Update uapi comments
  rseq: Use get_user/put_user rather than __get_user/__put_user
  rseq: Use __u64 for rseq_cs fields, validate user inputs

1 files changed, 25 insertions, 16 deletions

diff --git a/kernel/rseq.c b/kernel/rseq.c
index 22b6acf1ad63..c6242d8594dc 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -85,9 +85,9 @@ static int rseq_update_cpu_id(struct task_struct *t)
 {
 	u32 cpu_id = raw_smp_processor_id();
 
-	if (__put_user(cpu_id, &t->rseq->cpu_id_start))
+	if (put_user(cpu_id, &t->rseq->cpu_id_start))
 		return -EFAULT;
-	if (__put_user(cpu_id, &t->rseq->cpu_id))
+	if (put_user(cpu_id, &t->rseq->cpu_id))
 		return -EFAULT;
 	trace_rseq_update(t);
 	return 0;
@@ -100,14 +100,14 @@ static int rseq_reset_rseq_cpu_id(struct task_struct *t)
 	/*
 	 * Reset cpu_id_start to its initial state (0).
 	 */
-	if (__put_user(cpu_id_start, &t->rseq->cpu_id_start))
+	if (put_user(cpu_id_start, &t->rseq->cpu_id_start))
 		return -EFAULT;
 	/*
 	 * Reset cpu_id to RSEQ_CPU_ID_UNINITIALIZED, so any user coming
 	 * in after unregistration can figure out that rseq needs to be
 	 * registered again.
 	 */
-	if (__put_user(cpu_id, &t->rseq->cpu_id))
+	if (put_user(cpu_id, &t->rseq->cpu_id))
 		return -EFAULT;
 	return 0;
 }
@@ -115,29 +115,36 @@ static int rseq_reset_rseq_cpu_id(struct task_struct *t)
 static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
 {
 	struct rseq_cs __user *urseq_cs;
-	unsigned long ptr;
+	u64 ptr;
 	u32 __user *usig;
 	u32 sig;
 	int ret;
 
-	ret = __get_user(ptr, &t->rseq->rseq_cs);
-	if (ret)
-		return ret;
+	if (copy_from_user(&ptr, &t->rseq->rseq_cs.ptr64, sizeof(ptr)))
+		return -EFAULT;
 	if (!ptr) {
 		memset(rseq_cs, 0, sizeof(*rseq_cs));
 		return 0;
 	}
-	urseq_cs = (struct rseq_cs __user *)ptr;
+	if (ptr >= TASK_SIZE)
+		return -EINVAL;
+	urseq_cs = (struct rseq_cs __user *)(unsigned long)ptr;
 	if (copy_from_user(rseq_cs, urseq_cs, sizeof(*rseq_cs)))
 		return -EFAULT;
-	if (rseq_cs->version > 0)
-		return -EINVAL;
 
+	if (rseq_cs->start_ip >= TASK_SIZE ||
+	    rseq_cs->start_ip + rseq_cs->post_commit_offset >= TASK_SIZE ||
+	    rseq_cs->abort_ip >= TASK_SIZE ||
+	    rseq_cs->version > 0)
+		return -EINVAL;
+	/* Check for overflow. */
+	if (rseq_cs->start_ip + rseq_cs->post_commit_offset < rseq_cs->start_ip)
+		return -EINVAL;
 	/* Ensure that abort_ip is not in the critical section. */
 	if (rseq_cs->abort_ip - rseq_cs->start_ip < rseq_cs->post_commit_offset)
 		return -EINVAL;
 
-	usig = (u32 __user *)(rseq_cs->abort_ip - sizeof(u32));
+	usig = (u32 __user *)(unsigned long)(rseq_cs->abort_ip - sizeof(u32));
 	ret = get_user(sig, usig);
 	if (ret)
 		return ret;
@@ -146,7 +153,7 @@ static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
 		printk_ratelimited(KERN_WARNING
 			"Possible attack attempt. Unexpected rseq signature 0x%x, expecting 0x%x (pid=%d, addr=%p).\n",
 			sig, current->rseq_sig, current->pid, usig);
-		return -EPERM;
+		return -EINVAL;
 	}
 	return 0;
 }
@@ -157,7 +164,7 @@ static int rseq_need_restart(struct task_struct *t, u32 cs_flags)
 	int ret;
 
 	/* Get thread flags. */
-	ret = __get_user(flags, &t->rseq->flags);
+	ret = get_user(flags, &t->rseq->flags);
 	if (ret)
 		return ret;
 
@@ -195,9 +202,11 @@ static int clear_rseq_cs(struct task_struct *t)
 	 * of code outside of the rseq assembly block. This performs
 	 * a lazy clear of the rseq_cs field.
 	 *
-	 * Set rseq_cs to NULL with single-copy atomicity.
+	 * Set rseq_cs to NULL.
 	 */
-	return __put_user(0UL, &t->rseq->rseq_cs);
+	if (clear_user(&t->rseq->rseq_cs.ptr64, sizeof(t->rseq->rseq_cs.ptr64)))
+		return -EFAULT;
+	return 0;
 }
 
 /*