mvumi_hs_process_page() takes max_io, the two command entry sizes and the list depth from the firmware handshake page. The entry sizes are u8 fields used as shift counts, and 1 is an int, so a count of 29 or more makes the << 2 applied to the shift overflow an int; a count of 32 or more is undefined outright. max_io is a u16, and the sizes derived from the shifts are multiplied by it in mvumi_init_data() to size three unsigned int allocations, so a large entry size wraps the product and the loops that follow then walk and write past the short allocation. The list depth is used as a shift count too, but only when the firmware sets HS_CAPABILITY_NEW_PAGE_IO_DEPTH_DEF; a count of 32 or more is undefined there as well. Nothing bounds the entry sizes from below either, and an entry has to hold what the driver puts in it: a command frame and at least one scatter-gather element going in, a response frame and sense data coming back. An entry size of 32 bytes or less makes mvumi_internal_cmd_sgl() write its element past an inbound entry, since it writes one whatever host->sg_tablesize says, and makes mvumi_complete_cmd() read sense data past an outbound one; it also makes the max_sg subtraction in mvumi_io_attach() wrap, which hands mvumi_build_frame() and mvumi_send_command() a table size no entry can hold. The depth also sets how many entries the inbound and outbound rings hold, and the per-command slot index wraps on that count while the rings are allocated for max_io entries, so a depth yielding more entries than max_io -- or none -- walks the index past them. max_devices_support sizes the target_map bitmap in the same allocation, and it is a u16 while mvumi_build_frame() packs the target id into the low byte of device_id and the LUN into the high byte, so a target of 256 or more aliases another device's LUN; it is also what makes the unsigned char loop counter in mvumi_flush_cache() wrap before it reaches the bound, which never ends that loop. A host reset runs the handshake again, but mvumi_init_data() returns early once MVUMI_FW_ALLOC is set, so the buffers keep the sizes they were allocated with while the newly reported values drive the indexing: mvumi_flush_cache() then reads target_map past its end and mvumi_sdev_configure() sets a bit past it. The handshake is retried as well, because mvumi_handshake_event() discards the error, so a page that was already rejected can be presented again. Reject an entry size above 29, which keeps 1U << n and the shift that follows it inside an unsigned int, and reject one too small to hold those frames. Reject a device count the frame layout cannot address, which also keeps mvumi_flush_cache() terminating. Then compute the worst-case allocation size in u64 at the top of mvumi_init_data() and reject it if it does not fit an unsigned int. That total bounds all three allocations: the inbound list total, the outbound data pool and the tag arrays, whose sizes are the same products plus smaller terms. Reject a list depth of 32 or more on the shifted path so the shift stays defined, and reject a resulting entry count that is zero or above max_io so the slot index cannot walk past the rings. The shifts also use 1U now so that a legal count cannot overflow an int. Take every field the page carries into a local with READ_ONCE(), and run every check and every assignment on those. The page is coherent DMA memory, so a second fetch of a field is not the value that was checked: a second fetch of an entry size could turn a count of 29 into one of 31, a second fetch of the list depth could turn 31 into 32, which is the undefined shift the check exists to stop, and a second fetch of the device count could put a value above 255 into mhba->max_target_id after the bound above has passed. Once MVUMI_FW_ALLOC is set the buffers already exist, so only check that no reported size, max_devices_support included, is larger than the one its buffer was allocated for, and leave the size fields alone: they already hold the sizes those buffers have. Only the first handshake, whose values size the allocations, assigns them. No realistic controller is rejected: one reporting 4096 commands with 64 KiB entries and a depth of 12 needs 512 MiB and passes unchanged. The device count is the one new bound that could turn a controller away, and a controller reporting more than 255 devices is already one this driver cannot address. Fixes: f0c568a478f0 ("[SCSI] mvumi: Add Marvell UMI driver") Cc: stable@vger.kernel.org Signed-off-by: Yehyeong Lee --- drivers/scsi/mvumi.c | 124 ++++++++++++++++++++++++++++++++++++++----- drivers/scsi/mvumi.h | 6 +++ 2 files changed, 117 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c index 18964e860ac8e..8b8e5545747e8 100644 --- a/drivers/scsi/mvumi.c +++ b/drivers/scsi/mvumi.c @@ -912,10 +912,23 @@ static int mvumi_init_data(struct mvumi_hba *mhba) unsigned int tmp_size, offset, i; void *virmem, *v; dma_addr_t p; + u64 total; if (mhba->fw_flag & MVUMI_FW_ALLOC) return 0; + /* These are firmware-supplied and size the allocations below. */ + total = (u64)mhba->ib_max_size * mhba->max_io + + (u64)mhba->ob_max_size * mhba->max_io + + sizeof(struct mvumi_dyn_list_entry) * (u64)mhba->max_io + + 160; + if (total > UINT_MAX) { + dev_err(&mhba->pdev->dev, + "handshake sizes too large: io %u, in %u, out %u\n", + mhba->max_io, mhba->ib_max_size, mhba->ob_max_size); + return -1; + } + tmp_size = mhba->ib_max_size * mhba->max_io; if (mhba->hba_capability & HS_CAPABILITY_SUPPORT_DYN_SRC) tmp_size += sizeof(struct mvumi_dyn_list_entry) * mhba->max_io; @@ -1054,30 +1067,115 @@ static int mvumi_hs_process_page(struct mvumi_hba *mhba, } switch (hs_header->page_code) { - case HS_PAGE_FIRM_CAP: + case HS_PAGE_FIRM_CAP: { + unsigned int new_max_io, new_ib_max_size, new_ob_max_size; + unsigned int new_list_num_io; + unsigned short new_max_target_id, new_capability; + unsigned int new_max_transfer_size; + u8 in_sz, out_sz, list_depth; + hs_page1 = (struct mvumi_hs_page1 *) hs_header; - mhba->max_io = hs_page1->max_io_support; - mhba->list_num_io = hs_page1->cl_inout_list_depth; - mhba->max_transfer_size = hs_page1->max_transfer_size; - mhba->max_target_id = hs_page1->max_devices_support; - mhba->hba_capability = hs_page1->capability; - mhba->ib_max_size_setting = hs_page1->cl_in_max_entry_size; - mhba->ib_max_size = (1 << hs_page1->cl_in_max_entry_size) << 2; + /* + * The page is in coherent DMA memory, so take every field + * out of it once: a second fetch of a value that has already + * been checked would not be the value that was checked. + */ + in_sz = READ_ONCE(hs_page1->cl_in_max_entry_size); + out_sz = READ_ONCE(hs_page1->cl_out_max_entry_size); + list_depth = READ_ONCE(hs_page1->cl_inout_list_depth); + new_max_io = READ_ONCE(hs_page1->max_io_support); + new_max_target_id = READ_ONCE(hs_page1->max_devices_support); + new_capability = READ_ONCE(hs_page1->capability); + new_max_transfer_size = READ_ONCE(hs_page1->max_transfer_size); + + /* Firmware-supplied shift counts: (1U << n) << 2 must fit. */ + if (in_sz > 29 || out_sz > 29) { + dev_err(&mhba->pdev->dev, + "invalid handshake entry size\n"); + return -1; + } + + new_ib_max_size = (1U << in_sz) << 2; + new_ob_max_size = (1U << out_sz) << 2; + + /* + * A target above MVUMI_MAX_TARGET_ID cannot be addressed: its + * id would land in the LUN byte of device_id and alias another + * device. It is also what makes the loop counter in + * mvumi_flush_cache() wrap before it reaches the bound. + */ + if (new_max_target_id > MVUMI_MAX_TARGET_ID) { + dev_err(&mhba->pdev->dev, + "too many devices reported: %u\n", + new_max_target_id); + return -1; + } - mhba->ob_max_size_setting = hs_page1->cl_out_max_entry_size; - mhba->ob_max_size = (1 << hs_page1->cl_out_max_entry_size) << 2; + /* An entry has to hold the frame the driver puts in it. */ + if (new_ib_max_size < sizeof(struct mvumi_msg_frame) + + sizeof(struct mvumi_sgl) || + new_ob_max_size < sizeof(struct mvumi_rsp_frame) + + sizeof(struct mvumi_sense_data)) { + dev_err(&mhba->pdev->dev, + "handshake entry size too small: in %u, out %u\n", + new_ib_max_size, new_ob_max_size); + return -1; + } + + new_list_num_io = list_depth; + if (new_capability & HS_CAPABILITY_NEW_PAGE_IO_DEPTH_DEF) { + if (list_depth >= 32) { + dev_err(&mhba->pdev->dev, + "invalid handshake list depth\n"); + return -1; + } + new_list_num_io = 1U << list_depth; + } + /* The rings hold max_io entries but the index wraps on list_num_io. */ + if (new_list_num_io == 0 || new_list_num_io > new_max_io) { + dev_err(&mhba->pdev->dev, + "invalid handshake list depth: %u entries for %u commands\n", + new_list_num_io, new_max_io); + return -1; + } dev_dbg(&mhba->pdev->dev, "FW version:%d\n", - hs_page1->fw_ver.ver_build); + READ_ONCE(hs_page1->fw_ver.ver_build)); + + /* A host reset does not reallocate, so the sizes have to stay + * the ones the buffers were allocated with. Only check that + * the firmware is not asking for more than they hold. + */ + if (mhba->fw_flag & MVUMI_FW_ALLOC) { + if (new_max_io > mhba->max_io || + new_ib_max_size > mhba->ib_max_size || + new_ob_max_size > mhba->ob_max_size || + new_list_num_io > mhba->list_num_io || + new_max_target_id > mhba->max_target_id) { + dev_err(&mhba->pdev->dev, + "handshake sizes grew across reset\n"); + return -1; + } + break; + } + + mhba->max_io = new_max_io; + mhba->list_num_io = new_list_num_io; + mhba->max_transfer_size = new_max_transfer_size; + mhba->max_target_id = new_max_target_id; + mhba->hba_capability = new_capability; + mhba->ib_max_size_setting = in_sz; + mhba->ib_max_size = new_ib_max_size; + mhba->ob_max_size_setting = out_sz; + mhba->ob_max_size = new_ob_max_size; if (mhba->hba_capability & HS_CAPABILITY_SUPPORT_COMPACT_SG) mhba->eot_flag = 22; else mhba->eot_flag = 27; - if (mhba->hba_capability & HS_CAPABILITY_NEW_PAGE_IO_DEPTH_DEF) - mhba->list_num_io = 1 << hs_page1->cl_inout_list_depth; break; + } default: dev_err(&mhba->pdev->dev, "handshake: page code error\n"); return -1; diff --git a/drivers/scsi/mvumi.h b/drivers/scsi/mvumi.h index 5d45f0d99e639..d20eea2b61a31 100644 --- a/drivers/scsi/mvumi.h +++ b/drivers/scsi/mvumi.h @@ -127,6 +127,12 @@ enum { /* size of the buffer the driver hands the firmware for event replies */ #define MVUMI_EVENT_BUF_SIZE 512 +/* + * mvumi_build_frame() packs the target id into the low byte of device_id + * and the LUN into the high byte, so only these ids can be addressed. + */ +#define MVUMI_MAX_TARGET_ID 255 + #define DEVICE_OFFLINE 0 #define DEVICE_ONLINE 1 -- 2.43.0