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authorGustavo A. R. Silva <gustavo@embeddedor.com>2019-06-10 10:04:12 -0500
committerJens Axboe <axboe@kernel.dk>2019-06-15 01:47:58 -0600
commitf1f8f292cd12292289cae87aac3a5c035186ec54 (patch)
tree849c847a9195ed97b0cb733da4e921aed6870ff5 /block/bio.c
parent78b90a2ce8424eb4be4a6a1623dc7c07af8303aa (diff)
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block: bio: Use struct_size() in kmalloc()
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct bio_map_data { ... struct iovec iov[]; }; instance = kmalloc(sizeof(sizeof(struct bio_map_data) + sizeof(struct iovec) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, iov, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/block/bio.c b/block/bio.c
index 683cbb40f051..4bcdcd3f63f4 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1120,8 +1120,7 @@ static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
if (data->nr_segs > UIO_MAXIOV)
return NULL;
- bmd = kmalloc(sizeof(struct bio_map_data) +
- sizeof(struct iovec) * data->nr_segs, gfp_mask);
+ bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
if (!bmd)
return NULL;
memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);