1 files changed, 11 insertions, 3 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index c2964d890c9a..ca651ac00660 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -832,6 +832,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
         unsigned long addr = *ppos;
         ssize_t copied;
         char *page;
+        unsigned int flags;
 
         if (!mm)
                 return 0;
@@ -844,6 +845,11 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
         if (!atomic_inc_not_zero(&mm->mm_users))
                 goto free;
 
+        /* Maybe we should limit FOLL_FORCE to actual ptrace users? */
+        flags = FOLL_FORCE;
+        if (write)
+                flags |= FOLL_WRITE;
+
         while (count > 0) {
                 int this_len = min_t(int, count, PAGE_SIZE);
 
@@ -852,7 +858,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
                         break;
                 }
 
-                this_len = access_remote_vm(mm, addr, page, this_len, write);
+                this_len = access_remote_vm(mm, addr, page, this_len, flags);
                 if (!this_len) {
                         if (!copied)
                                 copied = -EIO;
@@ -964,8 +970,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
                 max_len = min_t(size_t, PAGE_SIZE, count);
                 this_len = min(max_len, this_len);
 
-                retval = access_remote_vm(mm, (env_start + src),
-                        page, this_len, 0);
+                retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
 
                 if (retval <= 0) {
                         ret = retval;
@@ -1007,6 +1012,9 @@ static ssize_t auxv_read(struct file *file, char __user *buf,
 {
         struct mm_struct *mm = file->private_data;
         unsigned int nwords = 0;
+
+        if (!mm)
+                return 0;
         do {
                 nwords += 2;
         } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */