The patch titled
nommu: don't pass NULL pointers to fput() in do_mmap_pgoff()
has been added to the -mm tree. Its filename is
nommu-dont-pass-null-pointers-to-fput-in-do_mmap_pgoff.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: nommu: don't pass NULL pointers to fput() in do_mmap_pgoff()
From: David Howells <dhowells@xxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Acked-by: Robin Getz <rgetz@xxxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN mm/nommu.c~nommu-dont-pass-null-pointers-to-fput-in-do_mmap_pgoff mm/nommu.c
--- a/mm/nommu.c~nommu-dont-pass-null-pointers-to-fput-in-do_mmap_pgoff
+++ a/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);
_
Patches currently in -mm which might be from dhowells@xxxxxxxxxx are
origin.patch
linux-next.patch
nommu-dont-pass-null-pointers-to-fput-in-do_mmap_pgoff.patch
nommu-ignore-the-address-parameter-in-the-file_mmap-security-check.patch
frv-duplicate-output_buffer-of-e03.patch
rwsem-spinlock-remove-useless-function-exports.patch
rwsem-fix-rwsem_is_locked-bugs.patch
rwsem-fix-rwsem_is_locked-bugs-fix.patch
mutex-subsystem-synchro-test-module.patch
mutex-subsystem-synchro-test-module-add-missing-header-file.patch
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