Messages in this thread Patch in this message | | | Date | Tue, 10 Feb 2009 06:51:19 +0100 | From | Nick Piggin <> | Subject | [patch] mm: vmap fix overflow |
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This patch is appropriate for 2.6.28 too.
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The new vmap allocator can wrap the address and get confused in the case of large allocations or VMALLOC_END near the end of address space.
Problem reported by Christoph Hellwig on a 32-bit XFS workload.
Signed-off-by: Nick Piggin <npiggin@suse.de> --- mm/vmalloc.c | 6 ++++++ 1 file changed, 6 insertions(+)
Index: linux-2.6/mm/vmalloc.c =================================================================== --- linux-2.6.orig/mm/vmalloc.c +++ linux-2.6/mm/vmalloc.c @@ -334,6 +334,9 @@ retry: addr = ALIGN(vstart, align); spin_lock(&vmap_area_lock); + if (addr + size < addr) + goto overflow; + /* XXX: could have a last_hole cache */ n = vmap_area_root.rb_node; if (n) { @@ -365,6 +368,8 @@ retry: while (addr + size > first->va_start && addr + size <= vend) { addr = ALIGN(first->va_end + PAGE_SIZE, align); + if (addr + size < addr) + goto overflow; n = rb_next(&first->rb_node); if (n) @@ -375,6 +380,7 @@ retry: } found: if (addr + size > vend) { +overflow: spin_unlock(&vmap_area_lock); if (!purged) { purge_vmap_area_lazy();
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