[RFC][PATCH 14/18] fix a struct file leak in do_mmap_pgoff()

From: Al Viro
Date: Sat Dec 05 2009 - 15:19:12 EST



Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 18 ------------------
mm/util.c | 15 +++++++++++++++
2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 73f5e4b..fd49f40 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -949,24 +949,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (mm->map_count > sysctl_max_map_count)
return -ENOMEM;

- if (flags & MAP_HUGETLB) {
- struct user_struct *user = NULL;
- if (file)
- return -EINVAL;
-
- /*
- * VM_NORESERVE is used because the reservations will be
- * taken when vm_ops->mmap() is called
- * A dummy user value is used because we are not locking
- * memory so no accounting is necessary
- */
- len = ALIGN(len, huge_page_size(&default_hstate));
- file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
- &user, HUGETLB_ANONHUGE_INODE);
- if (IS_ERR(file))
- return PTR_ERR(file);
- }
-
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
diff --git a/mm/util.c b/mm/util.c
index 3bf81b2..b377ce4 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -280,9 +280,24 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
unsigned long retval = -EBADF;

if (!(flags & MAP_ANONYMOUS)) {
+ if (unlikely(flags & MAP_HUGETLB))
+ return -EINVAL;
file = fget(fd);
if (!file)
goto out;
+ } else if (flags & MAP_HUGETLB) {
+ struct user_struct *user = NULL;
+ /*
+ * VM_NORESERVE is used because the reservations will be
+ * taken when vm_ops->mmap() is called
+ * A dummy user value is used because we are not locking
+ * memory so no accounting is necessary
+ */
+ len = ALIGN(len, huge_page_size(&default_hstate));
+ file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
+ &user, HUGETLB_ANONHUGE_INODE);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
}

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
--
1.5.6.5


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