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| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2010-10-26 15:41:28 -0600 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2010-10-26 15:33:28 -0700 |
| commit | a1862e31079149a52b6223776228c3aee493d4a7 (patch) | |
| tree | f70f7e3f33f63dcf77428b745f0dd01ecbee8e24 | |
| parent | 6909ba14c25b4db6be2ff89f4fa0fac2d70151a0 (diff) | |
| download | linux-a1862e31079149a52b6223776228c3aee493d4a7.tar.gz linux-a1862e31079149a52b6223776228c3aee493d4a7.tar.xz | |
resources: handle overflow when aligning start of available area
If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would
make us think there's more available space than there really is. We
would likely return something that conflicts with a previous resource,
which would cause a failure when allocate_resource() requests the newly-
allocated region.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027
Reported-by: Fabrice Bellet <fabrice@bellet.info>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
| -rw-r--r-- | kernel/resource.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 89d50412508c..e15b922d4ba4 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -392,7 +392,7 @@ static int find_resource(struct resource *root, struct resource *new, void *alignf_data) { struct resource *this = root->child; - struct resource tmp = *new, alloc; + struct resource tmp = *new, avail, alloc; tmp.start = root->start; /* @@ -410,14 +410,19 @@ static int find_resource(struct resource *root, struct resource *new, tmp.end = root->end; resource_clip(&tmp, min, max); - tmp.start = ALIGN(tmp.start, align); - alloc.start = alignf(alignf_data, &tmp, size, align); - alloc.end = alloc.start + size - 1; - if (resource_contains(&tmp, &alloc)) { - new->start = alloc.start; - new->end = alloc.end; - return 0; + /* Check for overflow after ALIGN() */ + avail = *new; + avail.start = ALIGN(tmp.start, align); + avail.end = tmp.end; + if (avail.start >= tmp.start) { + alloc.start = alignf(alignf_data, &avail, size, align); + alloc.end = alloc.start + size - 1; + if (resource_contains(&avail, &alloc)) { + new->start = alloc.start; + new->end = alloc.end; + return 0; + } } if (!this) break; |