diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c index 54abf9e303b7d66c4f41de1ef1ff17197572d292..f1c8cae70b4ba0c8de108a88ee72ecc26def140a 100644 --- a/drivers/md/dm-log-userspace-transfer.c +++ b/drivers/md/dm-log-userspace-transfer.c @@ -172,11 +172,15 @@ int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type, { int r = 0; size_t dummy = 0; - int overhead_size = - sizeof(struct dm_ulog_request *) + sizeof(struct cn_msg); + int overhead_size = sizeof(struct dm_ulog_request) + sizeof(struct cn_msg); struct dm_ulog_request *tfr = prealloced_ulog_tfr; struct receiving_pkg pkg; + /* + * Given the space needed to hold the 'struct cn_msg' and + * 'struct dm_ulog_request' - do we have enough payload + * space remaining? + */ if (data_size > (DM_ULOG_PREALLOCED_SIZE - overhead_size)) { DMINFO("Size of tfr exceeds preallocated size"); return -EINVAL; @@ -191,7 +195,7 @@ int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type, */ mutex_lock(&dm_ulog_lock); - memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - overhead_size); + memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - sizeof(struct cn_msg)); memcpy(tfr->uuid, uuid, DM_UUID_LEN); tfr->luid = luid; tfr->seq = dm_ulog_seq++;