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Christoph Böhmwalder authored
Commit c347a787 (drbd: set ->bi_bdev in drbd_req_new) moved a bio_set_dev call (which has since been removed) to "earlier", from drbd_request_prepare to drbd_req_new. The problem is that this accesses device->ldev->backing_bdev, which is not NULL-checked at this point. When we don't have an ldev (i.e. when the DRBD device is diskless), this leads to a null pointer deref. So, only allocate the private_bio if we actually have a disk. This is also a small optimization, since we don't clone the bio to only to immediately free it again in the diskless case. Fixes: c347a787 ("drbd: set ->bi_bdev in drbd_req_new") Co-developed-by:
Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Signed-off-by:
Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Co-developed-by:
Joel Colledge <joel.colledge@linbit.com> Signed-off-by:
Joel Colledge <joel.colledge@linbit.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221020085205.129090-1-christoph.boehmwalder@linbit.comSigned-off-by:
Jens Axboe <axboe@kernel.dk>
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