From cd4ad4b9dda686bce57f939671cc066a554b7f92 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Oct 2009 13:13:26 +0000 Subject: [PATCH] NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff() commit 89a8640279f8bb78aaf778d1fc5c4a6778f18064 upstream. Don't pass NULL pointers to fput() in the error handling paths of the NOMMU do_mmap_pgoff() as it can't handle it. The following can be used as a test program: int main() { static long long a[1024 * 1024 * 20] = { 0 }; return a;} Without the patch, the code oopses in atomic_long_dec_and_test() as called by fput() after the kernel complains that it can't allocate that big a chunk of memory. With the patch, the kernel just complains about the allocation size and then the program segfaults during execve() as execve() can't complete the allocation of all the new ELF program segments. Reported-by: Robin Getz Signed-off-by: David Howells Acked-by: Robin Getz Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/nommu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 82fedca8457..10cdd4c6129 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1384,9 +1384,11 @@ share: error_just_free: up_write(&nommu_region_sem); error: - fput(region->vm_file); + if (region->vm_file) + fput(region->vm_file); kmem_cache_free(vm_region_jar, region); - fput(vma->vm_file); + if (vma->vm_file) + fput(vma->vm_file); if (vma->vm_flags & VM_EXECUTABLE) removed_exe_file_vma(vma->vm_mm); kmem_cache_free(vm_area_cachep, vma); -- 2.11.4.GIT