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Commit 6d7825b1 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

mm/fremap.c: fix oops on error path 



If find_vma() fails, sys_remap_file_pages() will dereference `vma', which
contains NULL.  Fix it by checking the pointer.

(We could alternatively check for err==0, but this seems more direct)

(The vm_flags change is to squish a bogus used-uninitialised warning
without adding extra code).

Reported-by: default avatarTommi Rantala <tt.rantala@gmail.com>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c8615d37

mm/fremap.c

+4 −2
Original line number Diff line number Diff line
@@ -163,7 +163,8 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, 
	 * and that the remapped range is valid and fully within

	 * the single existing vma.

	 */

	if (!vma || !(vma->vm_flags & VM_SHARED))

	vm_flags = vma->vm_flags;

	if (!vma || !(vm_flags & VM_SHARED))

		goto out;



	if (!vma->vm_ops || !vma->vm_ops->remap_pages)
@@ -254,6 +255,7 @@ get_write_lock: 
	 */



out:

	if (vma)

		vm_flags = vma->vm_flags;

	if (likely(!has_write_lock))

		up_read(&mm->mmap_sem);