diff options
| -rw-r--r-- | kernel/kexec_core.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 704534029a00..561675589511 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -146,6 +146,7 @@ EXPORT_SYMBOL_GPL(kexec_crash_loaded); * allocating pages whose destination address we do not care about. */ #define KIMAGE_NO_DEST (-1UL) +#define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) static struct page *kimage_alloc_page(struct kimage *image, gfp_t gfp_mask, @@ -155,6 +156,7 @@ int sanity_check_segment_list(struct kimage *image) { int i; unsigned long nr_segments = image->nr_segments; + unsigned long total_pages = 0; /* * Verify we have good destination addresses. The caller is @@ -215,6 +217,21 @@ int sanity_check_segment_list(struct kimage *image) } /* + * Verify that no more than half of memory will be consumed. If the + * request from userspace is too large, a large amount of time will be + * wasted allocating pages, which can cause a soft lockup. + */ + for (i = 0; i < nr_segments; i++) { + if (PAGE_COUNT(image->segment[i].memsz) > totalram_pages / 2) + return -EINVAL; + + total_pages += PAGE_COUNT(image->segment[i].memsz); + } + + if (total_pages > totalram_pages / 2) + return -EINVAL; + + /* * Verify we have good destination addresses. Normally * the caller is responsible for making certain we don't * attempt to load the new image into invalid or reserved |