3 files changed, 28 insertions, 12 deletions

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 330cf84d21fe..60353f5acc48 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -420,7 +420,7 @@ asmlinkage ssize_t sys32_pread(unsigned int fd, char * buf,
                 goto out;
         pos = merge_64(a4, a5);
         ret = rw_verify_area(READ, file, &pos, count);
-        if (ret)
+        if (ret < 0)
                 goto out;
         ret = -EINVAL;
         if (!file->f_op || !(read = file->f_op->read))
@@ -455,7 +455,7 @@ asmlinkage ssize_t sys32_pwrite(unsigned int fd, const char * buf,
                 goto out;
         pos = merge_64(a4, a5);
         ret = rw_verify_area(WRITE, file, &pos, count);
-        if (ret)
+        if (ret < 0)
                 goto out;
         ret = -EINVAL;
         if (!file->f_op || !(write = file->f_op->write))
diff --git a/fs/compat.c b/fs/compat.c
index 818634120b69..55ac0324aaf1 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1170,7 +1170,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
         }
 
         ret = rw_verify_area(type, file, pos, tot_len);
-        if (ret)
+        if (ret < 0)
                 goto out;
 
         fnv = NULL;
diff --git a/fs/read_write.c b/fs/read_write.c
index a091ee4f430d..df3468a22fea 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -14,6 +14,7 @@
 #include <linux/security.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
+#include <linux/pagemap.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -182,22 +183,33 @@ bad:
 }
 #endif
 
+/*
+ * rw_verify_area doesn't like huge counts. We limit
+ * them to something that fits in "int" so that others
+ * won't have to do range checks all the time.
+ */
+#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
 
 int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count)
 {
         struct inode *inode;
         loff_t pos;
 
-        if (unlikely(count > INT_MAX))
+        if (unlikely((ssize_t) count < 0))
                 goto Einval;
         pos = *ppos;
         if (unlikely((pos < 0) || (loff_t) (pos + count) < 0))
                 goto Einval;
 
         inode = file->f_dentry->d_inode;
-        if (inode->i_flock && MANDATORY_LOCK(inode))
-                return locks_mandatory_area(read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, inode, file, pos, count);
-        return 0;
+        if (inode->i_flock && MANDATORY_LOCK(inode)) {
+                int retval = locks_mandatory_area(
+                        read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
+                        inode, file, pos, count);
+                if (retval < 0)
+                        return retval;
+        }
+        return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
 
 Einval:
         return -EINVAL;
@@ -244,7 +256,8 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
                 return -EFAULT;
 
         ret = rw_verify_area(READ, file, pos, count);
-        if (!ret) {
+        if (ret >= 0) {
+                count = ret;
                 ret = security_file_permission (file, MAY_READ);
                 if (!ret) {
                         if (file->f_op->read)
@@ -295,7 +308,8 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
                 return -EFAULT;
 
         ret = rw_verify_area(WRITE, file, pos, count);
-        if (!ret) {
+        if (ret >= 0) {
+                count = ret;
                 ret = security_file_permission (file, MAY_WRITE);
                 if (!ret) {
                         if (file->f_op->write)
@@ -497,7 +511,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
         }
 
         ret = rw_verify_area(type, file, pos, tot_len);
-        if (ret)
+        if (ret < 0)
                 goto out;
         ret = security_file_permission(file, type == READ ? MAY_READ : MAY_WRITE);
         if (ret)
@@ -653,8 +667,9 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                 if (!(in_file->f_mode & FMODE_PREAD))
                         goto fput_in;
         retval = rw_verify_area(READ, in_file, ppos, count);
-        if (retval)
+        if (retval < 0)
                 goto fput_in;
+        count = retval;
 
         retval = security_file_permission (in_file, MAY_READ);
         if (retval)
@@ -674,8 +689,9 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                 goto fput_out;
         out_inode = out_file->f_dentry->d_inode;
         retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
-        if (retval)
+        if (retval < 0)
                 goto fput_out;
+        count = retval;
 
         retval = security_file_permission (out_file, MAY_WRITE);
         if (retval)