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Commit 0d7718f6 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by Ilya Dryomov
Browse files

ceph: fix error handling in ceph_read_iter 



In case __ceph_do_getattr returns an error and the retry_op in
ceph_read_iter is not READ_INLINE, then it's possible to invoke
__free_page on a page which is NULL, this naturally leads to a crash.
This can happen when, for example, a process waiting on a MDS reply
receives sigterm.

Fix this by explicitly checking whether the page is set or not.

Cc: stable@vger.kernel.org # 3.19+
Signed-off-by: default avatarNikolay Borisov <kernel@kyup.com>
Reviewed-by: default avatarYan, Zheng <zyan@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 4d73644b

fs/ceph/file.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -1272,6 +1272,7 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to) 
		statret = __ceph_do_getattr(inode, page,

		statret = __ceph_do_getattr(inode, page,

					    CEPH_STAT_CAP_INLINE_DATA, !!page);

					    CEPH_STAT_CAP_INLINE_DATA, !!page);

		if (statret < 0) {

		if (statret < 0) {

			if (page)

				__free_page(page);

				__free_page(page);

			if (statret == -ENODATA) {

			if (statret == -ENODATA) {

				BUG_ON(retry_op != READ_INLINE);

				BUG_ON(retry_op != READ_INLINE);