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authorRussell King <rmk+kernel@arm.linux.org.uk>2012-05-16 15:19:20 +0100
committerBen Hutchings <ben@decadent.org.uk>2012-05-20 22:56:49 +0100
commit6d4e481b77c311118d1cab9356e781ba56047f16 (patch)
tree38c0944acb64190d8f3d11a72aa9e718da0eeee6 /arch
parentb31a26af02788341aa8b9b1490ca30fb0bc47389 (diff)
ARM: prevent VM_GROWSDOWN mmaps extending below FIRST_USER_ADDRESS
commit 9b61a4d1b2064dbd0c9e61754305ac852170509f upstream. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/fault.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index aa33949fef60..4b0bc37b943d 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -267,7 +267,9 @@ good_area:
return fault;
check_stack:
- if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
+ /* Don't allow expansion below FIRST_USER_ADDRESS */
+ if (vma->vm_flags & VM_GROWSDOWN &&
+ addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr))
goto good_area;
out:
return fault;