Commit db776883 authored Apr 05, 2018 by Sridhar Parasuram

dm-bufio: Ensure reserved buffer is also allocated from get_free_pages pool

In cases where alloc_buffer fails to allocate there is a possibility for
a reserved buffer to be used. Currently the reserved buffer is allocated
from a vmalloc region and later in dm-verity hashing, the use of vmalloc'd
buffer results in a panic in BUG_ON(!virt_addr_valid(buf)) as the operation
is invalid. This change ensures that the reserved buffer is allocated from
a non-vmalloc'd region.

Change-Id: I401787bcc3cbf9c3837d3c7d569774dcce04b6c6
Signed-off-by: Sridhar Parasuram <sridhar@codeaurora.org>

parent 07fb2060

drivers/md/dm-bufio.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1730,7 +1730,8 @@ struct dm_bufio_client dm_bufio_client_create(struct block_device bdev, unsign
		mutex_unlock(&dm_bufio_clients_lock);

		while (c->need_reserved_buffers) {
		struct dm_buffer *b = alloc_buffer(c, GFP_KERNEL);
		struct dm_buffer *b = alloc_buffer(c,
		GFP_KERNEL \| __GFP_NORETRY);

		if (!b) {
		r = -ENOMEM;