From 571d1a7222851ef5075f55702074ed7713dba304 Mon Sep 17 00:00:00 2001 From: Koby Elbaz Date: Fri, 23 Dec 2022 15:02:05 +0200 Subject: [PATCH] habanalabs: protect access to dynamic mem 'user_mappings' When HL_INFO_USER_MAPPINGS IOCTL is called, we copy_to_user from a dynamically allocated memory - 'user_mappings'. Since freeing/allocating it happens in runtime (upon a page fault), it not unlikely to access it even before being initially allocated (i.e., accessing a NULL pointer). The solution is to simply mark the spot when the err info has been collected, and that way to know whether err info (either page fault or RAZWI) is available to be read. Signed-off-by: Koby Elbaz Reviewed-by: Oded Gabbay Signed-off-by: Oded Gabbay --- drivers/accel/habanalabs/common/device.c | 4 +++ drivers/accel/habanalabs/common/habanalabs.h | 4 +++ .../accel/habanalabs/common/habanalabs_drv.c | 2 ++ .../habanalabs/common/habanalabs_ioctl.c | 36 ++++++++++++------- 4 files changed, 33 insertions(+), 13 deletions(-) diff --git a/drivers/accel/habanalabs/common/device.c b/drivers/accel/habanalabs/common/device.c index e1b5a2c349860..6a05ab3fda236 100644 --- a/drivers/accel/habanalabs/common/device.c +++ b/drivers/accel/habanalabs/common/device.c @@ -2441,6 +2441,8 @@ void hl_capture_razwi(struct hl_device *hdev, u64 addr, u16 *engine_id, u16 num_ memcpy(&razwi_info->razwi.engine_id[0], &engine_id[0], num_of_engines * sizeof(u16)); razwi_info->razwi.flags = flags; + + razwi_info->razwi_info_available = true; } void hl_handle_razwi(struct hl_device *hdev, u64 addr, u16 *engine_id, u16 num_of_engines, @@ -2526,6 +2528,8 @@ void hl_capture_page_fault(struct hl_device *hdev, u64 addr, u16 eng_id, bool is pgf_info->page_fault.addr = addr; pgf_info->page_fault.engine_id = eng_id; hl_capture_user_mappings(hdev, is_pmmu); + + pgf_info->page_fault_info_available = true; } void hl_handle_page_fault(struct hl_device *hdev, u64 addr, u16 eng_id, bool is_pmmu, diff --git a/drivers/accel/habanalabs/common/habanalabs.h b/drivers/accel/habanalabs/common/habanalabs.h index e578645acba96..cd474422163d8 100644 --- a/drivers/accel/habanalabs/common/habanalabs.h +++ b/drivers/accel/habanalabs/common/habanalabs.h @@ -2984,12 +2984,14 @@ struct undefined_opcode_info { * Since we're looking for the page-fault's root cause, * we don't care of the others that might follow it- * so once changed to 1, it will remain that way. + * @page_fault_info_available: indicates that a page fault info is now available. */ struct page_fault_info { struct hl_page_fault_info page_fault; struct hl_user_mapping *user_mappings; u64 num_of_user_mappings; atomic_t page_fault_detected; + bool page_fault_info_available; }; /** @@ -3000,10 +3002,12 @@ struct page_fault_info { * Since we're looking for the RAZWI's root cause, * we don't care of the others that might follow it- * so once changed to 1, it will remain that way. + * @razwi_info_available: indicates that a RAZWI info is now available. */ struct razwi_info { struct hl_info_razwi_event razwi; atomic_t razwi_detected; + bool razwi_info_available; }; /** diff --git a/drivers/accel/habanalabs/common/habanalabs_drv.c b/drivers/accel/habanalabs/common/habanalabs_drv.c index d7fe0af33bca3..03dae57dc8386 100644 --- a/drivers/accel/habanalabs/common/habanalabs_drv.c +++ b/drivers/accel/habanalabs/common/habanalabs_drv.c @@ -225,6 +225,8 @@ int hl_device_open(struct inode *inode, struct file *filp) atomic_set(&hdev->captured_err_info.razwi_info.razwi_detected, 0); atomic_set(&hdev->captured_err_info.page_fault_info.page_fault_detected, 0); hdev->captured_err_info.undef_opcode.write_enable = true; + hdev->captured_err_info.razwi_info.razwi_info_available = false; + hdev->captured_err_info.page_fault_info.page_fault_info_available = false; hdev->open_counter++; hdev->last_successful_open_jif = jiffies; diff --git a/drivers/accel/habanalabs/common/habanalabs_ioctl.c b/drivers/accel/habanalabs/common/habanalabs_ioctl.c index 949d385271603..72493bf94ba31 100644 --- a/drivers/accel/habanalabs/common/habanalabs_ioctl.c +++ b/drivers/accel/habanalabs/common/habanalabs_ioctl.c @@ -607,16 +607,20 @@ static int cs_timeout_info(struct hl_fpriv *hpriv, struct hl_info_args *args) static int razwi_info(struct hl_fpriv *hpriv, struct hl_info_args *args) { + void __user *out = (void __user *) (uintptr_t) args->return_pointer; struct hl_device *hdev = hpriv->hdev; u32 max_size = args->return_size; - struct hl_info_razwi_event *info = &hdev->captured_err_info.razwi_info.razwi; - void __user *out = (void __user *) (uintptr_t) args->return_pointer; + struct razwi_info *razwi_info; if ((!max_size) || (!out)) return -EINVAL; - return copy_to_user(out, info, min_t(size_t, max_size, sizeof(struct hl_info_razwi_event))) - ? -EFAULT : 0; + razwi_info = &hdev->captured_err_info.razwi_info; + if (!razwi_info->razwi_info_available) + return 0; + + return copy_to_user(out, &razwi_info->razwi, + min_t(size_t, max_size, sizeof(struct hl_info_razwi_event))) ? -EFAULT : 0; } static int undefined_opcode_info(struct hl_fpriv *hpriv, struct hl_info_args *args) @@ -786,16 +790,20 @@ static int engine_status_info(struct hl_fpriv *hpriv, struct hl_info_args *args) static int page_fault_info(struct hl_fpriv *hpriv, struct hl_info_args *args) { + void __user *out = (void __user *) (uintptr_t) args->return_pointer; struct hl_device *hdev = hpriv->hdev; u32 max_size = args->return_size; - struct hl_page_fault_info *info = &hdev->captured_err_info.page_fault_info.page_fault; - void __user *out = (void __user *) (uintptr_t) args->return_pointer; + struct page_fault_info *pgf_info; if ((!max_size) || (!out)) return -EINVAL; - return copy_to_user(out, info, min_t(size_t, max_size, sizeof(struct hl_page_fault_info))) - ? -EFAULT : 0; + pgf_info = &hdev->captured_err_info.page_fault_info; + if (!pgf_info->page_fault_info_available) + return 0; + + return copy_to_user(out, &pgf_info->page_fault, + min_t(size_t, max_size, sizeof(struct hl_page_fault_info))) ? -EFAULT : 0; } static int user_mappings_info(struct hl_fpriv *hpriv, struct hl_info_args *args) @@ -806,18 +814,20 @@ static int user_mappings_info(struct hl_fpriv *hpriv, struct hl_info_args *args) struct page_fault_info *pgf_info; u64 actual_size; - pgf_info = &hdev->captured_err_info.page_fault_info; - args->array_size = pgf_info->num_of_user_mappings; - if (!out) return -EINVAL; + pgf_info = &hdev->captured_err_info.page_fault_info; + if (!pgf_info->page_fault_info_available) + return 0; + + args->array_size = pgf_info->num_of_user_mappings; + actual_size = pgf_info->num_of_user_mappings * sizeof(struct hl_user_mapping); if (user_buf_size < actual_size) return -ENOMEM; - return copy_to_user(out, pgf_info->user_mappings, min_t(size_t, user_buf_size, actual_size)) - ? -EFAULT : 0; + return copy_to_user(out, pgf_info->user_mappings, actual_size) ? -EFAULT : 0; } static int send_fw_generic_request(struct hl_device *hdev, struct hl_info_args *info_args) -- 2.30.2