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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2018-10-30 15:04:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-31 08:54:12 -0700 |
| commit | 4b408c74ee5a0b74fc9265c2fe39b0e7dec7c056 (patch) | |
| tree | 246fef299b54169bc2e6c9c298df9da367021069 /mm/gup_benchmark.c | |
| parent | ec131b2d7fa629edf88a1f51669d1b4a189cba44 (diff) | |
| download | linux-4b408c74ee5a0b74fc9265c2fe39b0e7dec7c056.tar.bz2 | |
mm/gup_benchmark.c: prevent integer overflow in ioctl
The concern here is that "gup->size" is a u64 and "nr_pages" is unsigned
long. On 32 bit systems we could trick the kernel into allocating fewer
pages than expected.
Link: http://lkml.kernel.org/r/20181025061546.hnhkv33diogf2uis@kili.mountain
Fixes: 64c349f4ae78 ("mm: add infrastructure for get_user_pages_fast() benchmarking")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup_benchmark.c')
| -rw-r--r-- | mm/gup_benchmark.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index debf11388a60..5b42d3d4b60a 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -27,6 +27,9 @@ static int __gup_benchmark_ioctl(unsigned int cmd, int nr; struct page **pages; + if (gup->size > ULONG_MAX) + return -EINVAL; + nr_pages = gup->size / PAGE_SIZE; pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); if (!pages) |