From 8bba8666e2487df4fc2422357d61a479576d51fb Mon Sep 17 00:00:00 2001 From: Chuck Tuffli Date: Mon, 29 Jun 2020 00:32:04 +0000 Subject: [PATCH] bhyve: validate the NVMe LBA start and count Add checks that the combination of Starting LBA and Number of Logical Blocks in a command will not exceed the range of the underlying storage. Note that because NVMe specifices the Starting LBA as a uint64_t, care must be taken when converting it and the block count to avoid an integer overflow. Fixes UNH Tests 2.2.3, 2.3.2, and 2.4.2 Tested by: Jason Tubnor MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D24895 --- usr.sbin/bhyve/pci_nvme.c | 67 +++++++++++++++++++++++++++++++-------- 1 file changed, 53 insertions(+), 14 deletions(-) diff --git a/usr.sbin/bhyve/pci_nvme.c b/usr.sbin/bhyve/pci_nvme.c index 7f6e0d394a87..a8034b17dc3e 100644 --- a/usr.sbin/bhyve/pci_nvme.c +++ b/usr.sbin/bhyve/pci_nvme.c @@ -1529,6 +1529,34 @@ pci_nvme_stats_write_read_update(struct pci_nvme_softc *sc, uint8_t opc, pthread_mutex_unlock(&sc->mtx); } +/* + * Check if the combination of Starting LBA (slba) and Number of Logical + * Blocks (nlb) exceeds the range of the underlying storage. + * + * Because NVMe specifies the SLBA in blocks as a uint64_t and blockif stores + * the capacity in bytes as a uint64_t, care must be taken to avoid integer + * overflow. + */ +static bool +pci_nvme_out_of_range(struct pci_nvme_blockstore *nvstore, uint64_t slba, + uint32_t nlb) +{ + size_t offset, bytes; + + /* Overflow check of multiplying Starting LBA by the sector size */ + if (slba >> (64 - nvstore->sectsz_bits)) + return (true); + + offset = slba << nvstore->sectsz_bits; + bytes = nlb << nvstore->sectsz_bits; + + /* Overflow check of Number of Logical Blocks */ + if ((nvstore->size - offset) < bytes) + return (true); + + return (false); +} + static int pci_nvme_append_iov_req(struct pci_nvme_softc *sc, struct pci_nvme_ioreq *req, uint64_t gpaddr, size_t size, int do_write, uint64_t lba) @@ -1830,20 +1858,20 @@ nvme_opc_write_read(struct pci_nvme_softc *sc, lba = ((uint64_t)cmd->cdw11 << 32) | cmd->cdw10; nblocks = (cmd->cdw12 & 0xFFFF) + 1; + if (pci_nvme_out_of_range(nvstore, lba, nblocks)) { + WPRINTF("%s command would exceed LBA range", __func__); + pci_nvme_status_genc(status, NVME_SC_LBA_OUT_OF_RANGE); + goto out; + } - bytes = nblocks * nvstore->sectsz; + bytes = nblocks << nvstore->sectsz_bits; if (bytes > NVME_MAX_DATA_SIZE) { WPRINTF("%s command would exceed MDTS", __func__); pci_nvme_status_genc(status, NVME_SC_INVALID_FIELD); goto out; } - offset = lba * nvstore->sectsz; - if ((offset + bytes) > nvstore->size) { - WPRINTF("%s command would exceed LBA range", __func__); - pci_nvme_status_genc(status, NVME_SC_LBA_OUT_OF_RANGE); - goto out; - } + offset = lba << nvstore->sectsz_bits; req->bytes = bytes; req->io_req.br_offset = lba; @@ -1921,8 +1949,9 @@ nvme_opc_dataset_mgmt(struct pci_nvme_softc *sc, if (cmd->cdw11 & NVME_DSM_ATTR_DEALLOCATE) { struct nvme_dsm_range *range; + size_t offset, bytes; uint32_t nr, r; - int sectsz = sc->nvstore.sectsz; + int sectsz_bits = sc->nvstore.sectsz_bits; /* * DSM calls are advisory only, and compliant controllers @@ -1947,10 +1976,13 @@ nvme_opc_dataset_mgmt(struct pci_nvme_softc *sc, nvme_prp_memcpy(sc->nsc_pi->pi_vmctx, cmd->prp1, cmd->prp2, (uint8_t *)range, NVME_MAX_DSM_TRIM, NVME_COPY_FROM_PRP); - if ((range[0].starting_lba * sectsz) > nvstore->size) { + if (pci_nvme_out_of_range(nvstore, range[0].starting_lba, + range[0].length)) { pci_nvme_status_genc(status, NVME_SC_LBA_OUT_OF_RANGE); goto out; } + offset = range[0].starting_lba << sectsz_bits; + bytes = range[0].length << sectsz_bits; /* * If the request is for more than a single range, store @@ -1962,8 +1994,8 @@ nvme_opc_dataset_mgmt(struct pci_nvme_softc *sc, nr = cmd->cdw10 & 0xff; req->io_req.br_iovcnt = 0; - req->io_req.br_offset = range[0].starting_lba * sectsz; - req->io_req.br_resid = range[0].length * sectsz; + req->io_req.br_offset = offset; + req->io_req.br_resid = bytes; if (nr == 0) { req->io_req.br_callback = pci_nvme_io_done; @@ -1971,12 +2003,19 @@ nvme_opc_dataset_mgmt(struct pci_nvme_softc *sc, struct iovec *iov = req->io_req.br_iov; for (r = 0; r <= nr; r++) { - if ((range[r].starting_lba * sectsz) > nvstore->size) { + if (pci_nvme_out_of_range(nvstore, range[r].starting_lba, + range[r].length)) { pci_nvme_status_genc(status, NVME_SC_LBA_OUT_OF_RANGE); goto out; } - iov[r].iov_base = (void *)(range[r].starting_lba * sectsz); - iov[r].iov_len = range[r].length * sectsz; + offset = range[r].starting_lba << sectsz_bits; + bytes = range[r].length << sectsz_bits; + if ((nvstore->size - offset) < bytes) { + pci_nvme_status_genc(status, NVME_SC_LBA_OUT_OF_RANGE); + goto out; + } + iov[r].iov_base = (void *)offset; + iov[r].iov_len = bytes; } req->io_req.br_callback = pci_nvme_dealloc_sm;