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authorDavid Howells <dhowells@redhat.com>2009-10-30 13:13:26 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-10-31 12:11:37 -0700
commit89a8640279f8bb78aaf778d1fc5c4a6778f18064 (patch)
treec768adbc88d0482d4fdd0ff8385fe77c01ae1534
parent2e2ec952350f25242f2e0539db16b1e46f9eb01b (diff)
NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff()
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 <rgetz@blackfin.uclinux.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Robin Getz <rgetz@blackfin.uclinux.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/nommu.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 5189b5aed8c..9876fa0c3ad 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1362,9 +1362,11 @@ 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);