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| author | Jonathan Steel <jon.steel@esentire.com> | 2008-09-22 22:57:45 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-09-23 17:09:14 +0200 |
| commit | f9092f358bc2ec5367621478811f046f82873376 (patch) | |
| tree | 12c91aff3aa1d32b2f747470c160093aab6bdabe /kernel | |
| parent | kernel-doc: allow structs whose members are all private (diff) | |
| download | linux-f9092f358bc2ec5367621478811f046f82873376.tar.xz linux-f9092f358bc2ec5367621478811f046f82873376.zip | |
kexec: fix segmentation fault in kimage_add_entry
A segmentation fault can occur in kimage_add_entry in kexec.c when loading
a kernel image into memory. The fault occurs because a page is requested
by calling kimage_alloc_page with gfp_mask GFP_KERNEL and the function may
actually return a page with gfp_mask GFP_HIGHUSER. The high mem page is
returned because it was swapped with the kernel page due to the kernel
page being a page that will shortly be copied to.
This patch ensures that kimage_alloc_page returns a page that was created
with the correct gfp flags.
I have verified the change and fixed the whitespace damage of the original
patch. Jonathan did a great job of tracking this down after he hit the
problem. -- Eric
Signed-off-by: Jonathan Steel <jon.steel@esentire.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kexec.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c index 59f3f0df35d4..aef265325cd3 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -753,8 +753,14 @@ static struct page *kimage_alloc_page(struct kimage *image, *old = addr | (*old & ~PAGE_MASK); /* The old page I have found cannot be a - * destination page, so return it. + * destination page, so return it if it's + * gfp_flags honor the ones passed in. */ + if (!(gfp_mask & __GFP_HIGHMEM) && + PageHighMem(old_page)) { + kimage_free_pages(old_page); + continue; + } addr = old_addr; page = old_page; break; |