proc: fix pagemap_read() error case

[mirror_ubuntu-kernels.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 30a6a72d05b2d3330a064946b506c906a32b133b..25b6a887adb916a93d20aa092481f67df451ff8c 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -771,18 +771,12 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
        if (!task)
                goto out;
 
-       mm = mm_for_maps(task);
-       ret = PTR_ERR(mm);
-       if (!mm || IS_ERR(mm))
-               goto out_task;
-
        ret = -EINVAL;
        /* file position must be aligned */
        if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
                goto out_task;
 
        ret = 0;
-
        if (!count)
                goto out_task;
 
@@ -790,7 +784,12 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
        pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
        ret = -ENOMEM;
        if (!pm.buffer)
-               goto out_mm;
+               goto out_task;
+
+       mm = mm_for_maps(task);
+       ret = PTR_ERR(mm);
+       if (!mm || IS_ERR(mm))
+               goto out_free;
 
        pagemap_walk.pmd_entry = pagemap_pte_range;
        pagemap_walk.pte_hole = pagemap_pte_hole;
@@ -833,7 +832,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
                len = min(count, PM_ENTRY_BYTES * pm.pos);
                if (copy_to_user(buf, pm.buffer, len)) {
                        ret = -EFAULT;
-                       goto out_free;
+                       goto out_mm;
                }
                copied += len;
                buf += len;
@@ -843,10 +842,10 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
        if (!ret || ret == PM_END_OF_BUFFER)
                ret = copied;
 
-out_free:
-       kfree(pm.buffer);
 out_mm:
        mmput(mm);
+out_free:
+       kfree(pm.buffer);
 out_task:
        put_task_struct(task);
 out: