From: Magdalena Schulfer <[email protected]> The tracing log headers parsed by fw_log_print_buffer() reside in DMA-shared BOs that the NPU firmware can write to.
fw_log_from_bo() validated log->header_size and log->size, but fw_log_print_buffer() re-read those same fields from shared memory afterwards, allowing a TOCTOU where firmware changes them between the check and the use, and making the host dereference out-of-bounds addresses while printing logs. Snapshot the validated values once with READ_ONCE() and pass them down explicitly in a new struct ivpu_fw_log_desc instead of re-reading them from the shared struct. Cc: [email protected] Fixes: d4e4257afa6e ("accel/ivpu: Add firmware tracing support") Signed-off-by: Magdalena Schulfer <[email protected]> Signed-off-by: Dawid Osuchowski <[email protected]> --- drivers/accel/ivpu/ivpu_fw_log.c | 76 +++++++++++++++++++------------- 1 file changed, 45 insertions(+), 31 deletions(-) diff --git a/drivers/accel/ivpu/ivpu_fw_log.c b/drivers/accel/ivpu/ivpu_fw_log.c index 716467aa3156..4f9055aa9d33 100644 --- a/drivers/accel/ivpu/ivpu_fw_log.c +++ b/drivers/accel/ivpu/ivpu_fw_log.c @@ -26,10 +26,17 @@ MODULE_PARM_DESC(fw_log_level, " error=" __stringify(IVPU_FW_LOG_ERROR) " fatal=" __stringify(IVPU_FW_LOG_FATAL)); +struct ivpu_fw_log_desc { + struct vpu_tracing_buffer_header *log; + u32 header_size; + u32 size; +}; + static int fw_log_from_bo(struct ivpu_device *vdev, struct ivpu_bo *bo, u32 *offset, - struct vpu_tracing_buffer_header **out_log) + struct ivpu_fw_log_desc *desc) { struct vpu_tracing_buffer_header *log; + u32 header_size, size; if ((*offset + sizeof(*log)) > ivpu_bo_size(bo)) return -EINVAL; @@ -39,26 +46,32 @@ static int fw_log_from_bo(struct ivpu_device *vdev, struct ivpu_bo *bo, u32 *off if (log->vpu_canary_start != VPU_TRACING_BUFFER_CANARY) return -EINVAL; - if (log->header_size < sizeof(*log) || log->header_size > 1024) { - ivpu_dbg(vdev, FW_BOOT, "Invalid header size 0x%x\n", log->header_size); + header_size = READ_ONCE(log->header_size); + size = READ_ONCE(log->size); + + if (header_size < sizeof(*log) || header_size > 1024) { + ivpu_dbg(vdev, FW_BOOT, "Invalid header size 0x%x\n", header_size); return -EINVAL; } - if (log->size < log->header_size) { - ivpu_dbg(vdev, FW_BOOT, "Invalid log size 0x%x\n", log->size); + if ((char *)log + size > (char *)ivpu_bo_vaddr(bo) + ivpu_bo_size(bo)) { + ivpu_dbg(vdev, FW_BOOT, "Invalid log size 0x%x\n", size); return -EINVAL; } - if ((char *)log + log->size > (char *)ivpu_bo_vaddr(bo) + ivpu_bo_size(bo)) { - ivpu_dbg(vdev, FW_BOOT, "Invalid log size 0x%x\n", log->size); + if (size < header_size) { + ivpu_dbg(vdev, FW_BOOT, "Invalid log size 0x%x < header size 0x%x\n", + size, header_size); return -EINVAL; } - *out_log = log; - *offset += log->size; + desc->log = log; + desc->header_size = header_size; + desc->size = size; + *offset += size; ivpu_dbg(vdev, FW_BOOT, "FW log name \"%s\", write offset 0x%x size 0x%x, wrap count %d, hdr version %d size %d format %d, alignment %d", - log->name, log->write_index, log->size, log->wrap_count, log->header_version, - log->header_size, log->format, log->alignment); + log->name, log->write_index, size, log->wrap_count, log->header_version, + header_size, log->format, log->alignment); return 0; } @@ -94,11 +107,12 @@ static void fw_log_print_lines(char *buffer, u32 size, struct drm_printer *p) drm_printf(p, "%s", line); } -static void fw_log_print_buffer(struct vpu_tracing_buffer_header *log, const char *prefix, +static void fw_log_print_buffer(struct ivpu_fw_log_desc *desc, const char *prefix, bool only_new_msgs, struct drm_printer *p) { - char *log_data = (void *)log + log->header_size; - u32 data_size = log->size - log->header_size; + struct vpu_tracing_buffer_header *log = desc->log; + char *log_data = (void *)log + desc->header_size; + u32 data_size = desc->size - desc->header_size; u32 log_start = only_new_msgs ? READ_ONCE(log->read_index) : 0; u32 log_end = READ_ONCE(log->write_index); @@ -134,11 +148,11 @@ static void fw_log_print_all_in_bo(struct ivpu_device *vdev, const char *name, struct ivpu_bo *bo, bool only_new_msgs, struct drm_printer *p) { - struct vpu_tracing_buffer_header *log; + struct ivpu_fw_log_desc desc; u32 next = 0; - while (fw_log_from_bo(vdev, bo, &next, &log) == 0) - fw_log_print_buffer(log, name, only_new_msgs, p); + while (fw_log_from_bo(vdev, bo, &next, &desc) == 0) + fw_log_print_buffer(&desc, name, only_new_msgs, p); } void ivpu_fw_log_print(struct ivpu_device *vdev, bool only_new_msgs, struct drm_printer *p) @@ -149,36 +163,36 @@ void ivpu_fw_log_print(struct ivpu_device *vdev, bool only_new_msgs, struct drm_ void ivpu_fw_log_mark_read(struct ivpu_device *vdev) { - struct vpu_tracing_buffer_header *log; + struct ivpu_fw_log_desc desc; u32 next; next = 0; - while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0) { - log->read_index = READ_ONCE(log->write_index); - log->read_wrap_count = READ_ONCE(log->wrap_count); + while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &desc) == 0) { + desc.log->read_index = READ_ONCE(desc.log->write_index); + desc.log->read_wrap_count = READ_ONCE(desc.log->wrap_count); } next = 0; - while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0) { - log->read_index = READ_ONCE(log->write_index); - log->read_wrap_count = READ_ONCE(log->wrap_count); + while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &desc) == 0) { + desc.log->read_index = READ_ONCE(desc.log->write_index); + desc.log->read_wrap_count = READ_ONCE(desc.log->wrap_count); } } void ivpu_fw_log_reset(struct ivpu_device *vdev) { - struct vpu_tracing_buffer_header *log; + struct ivpu_fw_log_desc desc; u32 next; next = 0; - while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0) { - log->read_index = 0; - log->read_wrap_count = 0; + while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &desc) == 0) { + desc.log->read_index = 0; + desc.log->read_wrap_count = 0; } next = 0; - while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0) { - log->read_index = 0; - log->read_wrap_count = 0; + while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &desc) == 0) { + desc.log->read_index = 0; + desc.log->read_wrap_count = 0; } } -- 2.43.0
