diff options
Diffstat (limited to 'drivers/nvme/target/discovery.c')
| -rw-r--r-- | drivers/nvme/target/discovery.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c index e9b35549e254..114869d16a1f 100644 --- a/drivers/nvme/target/discovery.c +++ b/drivers/nvme/target/discovery.c @@ -166,6 +166,7 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req) u64 offset = nvmet_get_log_page_offset(req->cmd); size_t data_len = nvmet_get_log_page_len(req->cmd); size_t alloc_len; + size_t copy_len; struct nvmet_subsys_link *p; struct nvmet_port *r; u32 numrec = 0; @@ -242,7 +243,27 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req) up_read(&nvmet_config_sem); - status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len); + /* + * Validate the host-supplied log page offset before copying out. + * Without this check, the host controls a 64-bit byte offset into + * a small kzalloc'd buffer: a value past the log page lets the + * subsequent memcpy read adjacent kernel heap, and a value aimed + * at unmapped kernel memory faults the in-kernel copy and crashes + * the target host. The Discovery controller is unauthenticated, + * so the bug is reachable from any reachable fabric peer. + */ + if (offset > alloc_len) { + req->error_loc = + offsetof(struct nvme_get_log_page_command, lpo); + status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + goto out_free_buffer; + } + + copy_len = min_t(size_t, data_len, alloc_len - offset); + status = nvmet_copy_to_sgl(req, 0, buffer + offset, copy_len); + if (!status && copy_len < data_len) + status = nvmet_zero_sgl(req, copy_len, data_len - copy_len); +out_free_buffer: kfree(buffer); out: nvmet_req_complete(req, status); |