scsi: ufs: core: Fix out-of-bounds warnings in ufshcd_exec_raw_upiu_cmd()

Fix the following out-of-bounds warnings by enclosing some structure
members into new structure objects upiu_req and upiu_rsp:

include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [29, 48] from the object at 'treq' is out of the bounds of referenced subobject 'req_header' with type 'struct utp_upiu_header' at offset 16 [-Warray-bounds]
include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [61, 80] from the object at 'treq' is out of the bounds of referenced subobject 'rsp_header' with type 'struct utp_upiu_header' at offset 48 [-Warray-bounds]
arch/m68k/include/asm/string.h:72:25: warning: '__builtin_memcpy' offset [29, 48] from the object at 'treq' is out of the bounds of referenced subobject 'req_header' with type 'struct utp_upiu_header' at offset 16 [-Warray-bounds]
arch/m68k/include/asm/string.h:72:25: warning: '__builtin_memcpy' offset [61, 80] from the object at 'treq' is out of the bounds of referenced subobject 'rsp_header' with type 'struct utp_upiu_header' at offset 48 [-Warray-bounds]

Refactor the code by making it more structured.

The problem is that the original code is trying to copy data into a bunch
of struct members adjacent to each other in a single call to memcpy(). Now
that a new struct _upiu_req_ enclosing all those adjacent members is
introduced, memcpy() doesn't overrun the length of &treq.req_header,
because the address of the new struct object _upiu_req_ is used as the
destination, instead. The same problem is present when memcpy() overruns
the length of the source &treq.rsp_header; in this case the address of the
new struct object _upiu_rsp_ is used, instead.

Also, this helps with the ongoing efforts to enable -Warray-bounds and
avoid confusing the compiler.

Link: https://github.com/KSPP/linux/issues/109
Link: https://lore.kernel.org/lkml/60640558.lsAxiK6otPwTo9rv%25lkp@intel.com/
Link: https://lore.kernel.org/r/20210331224338.GA347171@embeddedor
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Build-tested-by: kernel test robot <lkp@intel.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index acc6356..58d7f26 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -327,11 +327,15 @@ static void ufshcd_add_tm_upiu_trace(struct ufs_hba *hba, unsigned int tag,
                return;
 
        if (str_t == UFS_TM_SEND)
-               trace_ufshcd_upiu(dev_name(hba->dev), str_t, &descp->req_header,
-                                 &descp->input_param1, UFS_TSF_TM_INPUT);
+               trace_ufshcd_upiu(dev_name(hba->dev), str_t,
+                                 &descp->upiu_req.req_header,
+                                 &descp->upiu_req.input_param1,
+                                 UFS_TSF_TM_INPUT);
        else
-               trace_ufshcd_upiu(dev_name(hba->dev), str_t, &descp->rsp_header,
-                                 &descp->output_param1, UFS_TSF_TM_OUTPUT);
+               trace_ufshcd_upiu(dev_name(hba->dev), str_t,
+                                 &descp->upiu_rsp.rsp_header,
+                                 &descp->upiu_rsp.output_param1,
+                                 UFS_TSF_TM_OUTPUT);
 }
 
 static void ufshcd_add_uic_command_trace(struct ufs_hba *hba,
@@ -6398,7 +6402,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
        spin_lock_irqsave(host->host_lock, flags);
        task_tag = hba->nutrs + free_slot;
 
-       treq->req_header.dword_0 |= cpu_to_be32(task_tag);
+       treq->upiu_req.req_header.dword_0 |= cpu_to_be32(task_tag);
 
        memcpy(hba->utmrdl_base_addr + free_slot, treq, sizeof(*treq));
        ufshcd_vops_setup_task_mgmt(hba, free_slot, tm_function);
@@ -6471,16 +6475,16 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
        treq.header.dword_2 = cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
 
        /* Configure task request UPIU */
-       treq.req_header.dword_0 = cpu_to_be32(lun_id << 8) |
+       treq.upiu_req.req_header.dword_0 = cpu_to_be32(lun_id << 8) |
                                  cpu_to_be32(UPIU_TRANSACTION_TASK_REQ << 24);
-       treq.req_header.dword_1 = cpu_to_be32(tm_function << 16);
+       treq.upiu_req.req_header.dword_1 = cpu_to_be32(tm_function << 16);
 
        /*
         * The host shall provide the same value for LUN field in the basic
         * header and for Input Parameter.
         */
-       treq.input_param1 = cpu_to_be32(lun_id);
-       treq.input_param2 = cpu_to_be32(task_id);
+       treq.upiu_req.input_param1 = cpu_to_be32(lun_id);
+       treq.upiu_req.input_param2 = cpu_to_be32(task_id);
 
        err = __ufshcd_issue_tm_cmd(hba, &treq, tm_function);
        if (err == -ETIMEDOUT)
@@ -6491,7 +6495,7 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
                dev_err(hba->dev, "%s: failed, ocs = 0x%x\n",
                                __func__, ocs_value);
        else if (tm_response)
-               *tm_response = be32_to_cpu(treq.output_param1) &
+               *tm_response = be32_to_cpu(treq.upiu_rsp.output_param1) &
                                MASK_TM_SERVICE_RESP;
        return err;
 }
@@ -6666,7 +6670,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
                treq.header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
                treq.header.dword_2 = cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
 
-               memcpy(&treq.req_header, req_upiu, sizeof(*req_upiu));
+               memcpy(&treq.upiu_req, req_upiu, sizeof(*req_upiu));
 
                err = __ufshcd_issue_tm_cmd(hba, &treq, tm_f);
                if (err == -ETIMEDOUT)
@@ -6679,7 +6683,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
                        break;
                }
 
-               memcpy(rsp_upiu, &treq.rsp_header, sizeof(*rsp_upiu));
+               memcpy(rsp_upiu, &treq.upiu_rsp, sizeof(*rsp_upiu));
 
                break;
        default:

diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h
index 335ff7b..de95be5 100644 (file)
--- a/drivers/scsi/ufs/ufshci.h
+++ b/drivers/scsi/ufs/ufshci.h
@@ -486,17 +486,21 @@ struct utp_task_req_desc {
        struct request_desc_header header;
 
        /* DW 4-11 - Task request UPIU structure */
-       struct utp_upiu_header  req_header;
-       __be32                  input_param1;
-       __be32                  input_param2;
-       __be32                  input_param3;
-       __be32                  __reserved1[2];
+       struct {
+               struct utp_upiu_header  req_header;
+               __be32                  input_param1;
+               __be32                  input_param2;
+               __be32                  input_param3;
+               __be32                  __reserved1[2];
+       } upiu_req;
 
        /* DW 12-19 - Task Management Response UPIU structure */
-       struct utp_upiu_header  rsp_header;
-       __be32                  output_param1;
-       __be32                  output_param2;
-       __be32                  __reserved2[3];
+       struct {
+               struct utp_upiu_header  rsp_header;
+               __be32                  output_param1;
+               __be32                  output_param2;
+               __be32                  __reserved2[3];
+       } upiu_rsp;
 };
 
 #endif /* End of Header */