Messages in this thread Patch in this message | | | Date | Thu, 6 Mar 2003 12:29:14 +0000 (GMT) | From | Hugh Dickins <> | Subject | [PATCH] vm_area_struct slab corruption |
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Fix vm_area_struct slab corruption due to mremap's move_vma mistaking (okay, okay, _my_ mistaking) how do_munmap splits vmas in one case.
This patch fits do_munmap to move_vma's expectation: you may well feel that's the wrong way round to fix it (and not the way I promised a few days ago), but at present I'm more comfortable with this simpler fix; and it does seem preferable for do_munmap to reuse the existing vma.
Hugh
--- 2.5.64/mm/mmap.c Wed Mar 5 07:26:34 2003 +++ linux/mm/mmap.c Thu Mar 6 11:47:44 2003 @@ -1258,20 +1258,24 @@ /* * If we need to split any vma, do it now to save pain later. + * + * Note: mremap's move_vma VM_ACCOUNT handling assumes a partially + * unmapped vm_area_struct will remain in use: so lower split_vma + * places tmp vma above, and higher split_vma places tmp vma below. */ if (start > mpnt->vm_start) { if (split_vma(mm, mpnt, start, 0)) return -ENOMEM; prev = mpnt; - mpnt = mpnt->vm_next; } /* Does it split the last one? */ last = find_vma(mm, end); if (last && end > last->vm_start) { - if (split_vma(mm, last, end, 0)) + if (split_vma(mm, last, end, 1)) return -ENOMEM; } + mpnt = prev? prev->vm_next: mm->mmap; /* * Remove the vma's, and unmap the actual pages - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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