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authorNick Piggin <npiggin@suse.de>2009-02-27 14:03:03 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-27 16:26:21 -0800
commit7766970cc13e9071b356b1f2a48a9eb8675bfcce (patch)
tree615ebb34f392c882cc0b72e2958249a2f9f0ee19 /mm/vmalloc.c
parent5170836679185357dc1b7660bad13287b39e1e33 (diff)
downloadlinux-linaro-android-7766970cc13e9071b356b1f2a48a9eb8675bfcce.tar.gz
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.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 903cad46e79..ed3705e4b83 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();