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| author | Nick Piggin <npiggin@suse.de> | 2009-02-27 14:03:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-27 16:26:21 -0800 |
| commit | 7766970cc13e9071b356b1f2a48a9eb8675bfcce (patch) | |
| tree | 615ebb34f392c882cc0b72e2958249a2f9f0ee19 /mm/vmalloc.c | |
| parent | 5170836679185357dc1b7660bad13287b39e1e33 (diff) | |
| download | lwn-7766970cc13e9071b356b1f2a48a9eb8675bfcce.tar.gz lwn-7766970cc13e9071b356b1f2a48a9eb8675bfcce.zip | |
mm: vmap fix overflow
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>
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 903cad46e796..ed3705e4b83f 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -323,6 +323,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, unsigned long addr; int purged = 0; + BUG_ON(!size); BUG_ON(size & ~PAGE_MASK); va = kmalloc_node(sizeof(struct vmap_area), @@ -334,6 +335,9 @@ retry: addr = ALIGN(vstart, align); spin_lock(&vmap_area_lock); + if (addr + size - 1 < addr) + goto overflow; + /* XXX: could have a last_hole cache */ n = vmap_area_root.rb_node; if (n) { @@ -365,6 +369,8 @@ retry: while (addr + size > first->va_start && addr + size <= vend) { addr = ALIGN(first->va_end + PAGE_SIZE, align); + if (addr + size - 1 < addr) + goto overflow; n = rb_next(&first->rb_node); if (n) @@ -375,6 +381,7 @@ retry: } found: if (addr + size > vend) { +overflow: spin_unlock(&vmap_area_lock); if (!purged) { purge_vmap_area_lazy(); |