[PATCH AUTOSEL 5.10 02/53] scsi: be2iscsi: Fix use-after-free during IP updates

Sasha Levin
2021-09-10T00:55:11Z

From: Mike Christie <michael.christie@oracle.com>

[ Upstream commit 7b0ddc1346089b62b45e688e350c9e1c3f7a3ab2 ]

This fixes a bug found by Lv Yunlong where, because beiscsi_exec_nemb_cmd()
frees memory for the be_dma_mem cmd(), we can access freed memory when
beiscsi_if_clr_ip()/beiscsi_if_set_ip()'s call to beiscsi_exec_nemb_cmd()
fails and we access the freed req. This fixes the issue by having the
caller free the cmd's memory.

Link: https://lore.kernel.org/r/20210701190840.175120-1-michael.christie@oracle.com
Reported-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/be2iscsi/be_mgmt.c | 84 ++++++++++++++++++---------------
1 file changed, 45 insertions(+), 39 deletions(-)

diff --git a/drivers/scsi/be2iscsi/be_mgmt.c b/drivers/scsi/be2iscsi/be_mgmt.c
index 96d6e384b2b2..c1f79125cd0c 100644
--- a/drivers/scsi/be2iscsi/be_mgmt.c
+++ b/drivers/scsi/be2iscsi/be_mgmt.c
@@ -235,8 +235,7 @@ static int beiscsi_exec_nemb_cmd(struct beiscsi_hba *phba,
wrb = alloc_mcc_wrb(phba, &tag);
if (!wrb) {
mutex_unlock(&ctrl->mbox_lock);
- rc = -ENOMEM;
- goto free_cmd;
+ return -ENOMEM;
}

sge = nonembedded_sgl(wrb);
@@ -269,24 +268,6 @@ static int beiscsi_exec_nemb_cmd(struct beiscsi_hba *phba,
/* copy the response, if any */
if (resp_buf)
memcpy(resp_buf, nonemb_cmd->va, resp_buf_len);
- /**
- * This is special case of NTWK_GET_IF_INFO where the size of
- * response is not known. beiscsi_if_get_info checks the return
- * value to free DMA buffer.
- */
- if (rc == -EAGAIN)
- return rc;
-
- /**
- * If FW is busy that is driver timed out, DMA buffer is saved with
- * the tag, only when the cmd completes this buffer is freed.
- */
- if (rc == -EBUSY)
- return rc;
-
-free_cmd:
- dma_free_coherent(&ctrl->pdev->dev, nonemb_cmd->size,
- nonemb_cmd->va, nonemb_cmd->dma);
return rc;
}

@@ -309,6 +290,19 @@ static int beiscsi_prep_nemb_cmd(struct beiscsi_hba *phba,
return 0;
}

+static void beiscsi_free_nemb_cmd(struct beiscsi_hba *phba,
+ struct be_dma_mem *cmd, int rc)
+{
+ /*
+ * If FW is busy the DMA buffer is saved with the tag. When the cmd
+ * completes this buffer is freed.
+ */
+ if (rc == -EBUSY)
+ return;
+
+ dma_free_coherent(&phba->ctrl.pdev->dev, cmd->size, cmd->va, cmd->dma);
+}
+
static void __beiscsi_eq_delay_compl(struct beiscsi_hba *phba, unsigned int tag)
{
struct be_dma_mem *tag_mem;
@@ -344,8 +338,16 @@ int beiscsi_modify_eq_delay(struct beiscsi_hba *phba,
cpu_to_le32(set_eqd[i].delay_multiplier);
}

- return beiscsi_exec_nemb_cmd(phba, &nonemb_cmd,
- __beiscsi_eq_delay_compl, NULL, 0);
+ rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, __beiscsi_eq_delay_compl,
+ NULL, 0);
+ if (rc) {
+ /*
+ * Only free on failure. Async cmds are handled like -EBUSY
+ * where it's handled for us.
+ */
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
+ }
+ return rc;
}

/**
@@ -372,6 +374,7 @@ int beiscsi_get_initiator_name(struct beiscsi_hba *phba, char *name, bool cfg)
req->hdr.version = 1;
rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL,
&resp, sizeof(resp));
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
if (rc) {
beiscsi_log(phba, KERN_ERR,
BEISCSI_LOG_CONFIG | BEISCSI_LOG_MBOX,
@@ -449,7 +452,9 @@ static int beiscsi_if_mod_gw(struct beiscsi_hba *phba,
req->ip_addr.ip_type = ip_type;
memcpy(req->ip_addr.addr, gw,
(ip_type < BEISCSI_IP_TYPE_V6) ? IP_V4_LEN : IP_V6_LEN);
- return beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, NULL, 0);
+ rt_val = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, NULL, 0);
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rt_val);
+ return rt_val;
}

int beiscsi_if_set_gw(struct beiscsi_hba *phba, u32 ip_type, u8 *gw)
@@ -499,8 +504,10 @@ int beiscsi_if_get_gw(struct beiscsi_hba *phba, u32 ip_type,
req = nonemb_cmd.va;
req->ip_type = ip_type;

- return beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL,
- resp, sizeof(*resp));
+ rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, resp,
+ sizeof(*resp));
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
+ return rc;
}

static int
@@ -537,6 +544,7 @@ beiscsi_if_clr_ip(struct beiscsi_hba *phba,
"BG_%d : failed to clear IP: rc %d status %d\n",
rc, req->ip_params.ip_record.status);
}
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
return rc;
}

@@ -581,6 +589,7 @@ beiscsi_if_set_ip(struct beiscsi_hba *phba, u8 *ip,
if (req->ip_params.ip_record.status)
rc = -EINVAL;
}
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
return rc;
}

@@ -608,6 +617,7 @@ int beiscsi_if_en_static(struct beiscsi_hba *phba, u32 ip_type,
reldhcp->interface_hndl = phba->interface_handle;
reldhcp->ip_type = ip_type;
rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, NULL, 0);
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
if (rc < 0) {
beiscsi_log(phba, KERN_WARNING, BEISCSI_LOG_CONFIG,
"BG_%d : failed to release existing DHCP: %d\n",
@@ -689,7 +699,7 @@ int beiscsi_if_en_dhcp(struct beiscsi_hba *phba, u32 ip_type)
dhcpreq->interface_hndl = phba->interface_handle;
dhcpreq->ip_type = ip_type;
rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, NULL, 0);
-
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
exit:
kfree(if_info);
return rc;
@@ -762,11 +772,8 @@ int beiscsi_if_get_info(struct beiscsi_hba *phba, int ip_type,
BEISCSI_LOG_INIT | BEISCSI_LOG_CONFIG,
"BG_%d : Memory Allocation Failure\n");

- /* Free the DMA memory for the IOCTL issuing */
- dma_free_coherent(&phba->ctrl.pdev->dev,
- nonemb_cmd.size,
- nonemb_cmd.va,
- nonemb_cmd.dma);
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd,
+ -ENOMEM);
return -ENOMEM;
}

@@ -781,15 +788,13 @@ int beiscsi_if_get_info(struct beiscsi_hba *phba, int ip_type,
nonemb_cmd.va)->actual_resp_len;
ioctl_size += sizeof(struct be_cmd_req_hdr);

- /* Free the previous allocated DMA memory */
- dma_free_coherent(&phba->ctrl.pdev->dev, nonemb_cmd.size,
- nonemb_cmd.va,
- nonemb_cmd.dma);
-
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
/* Free the virtual memory */
kfree(*if_info);
- } else
+ } else {
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
break;
+ }
} while (true);
return rc;
}
@@ -806,8 +811,9 @@ int mgmt_get_nic_conf(struct beiscsi_hba *phba,
if (rc)
return rc;

- return beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL,
- nic, sizeof(*nic));
+ rc = beiscsi_exec_nemb_cmd(phba, &nonemb_cmd, NULL, nic, sizeof(*nic));
+ beiscsi_free_nemb_cmd(phba, &nonemb_cmd, rc);
+ return rc;
}

static void beiscsi_boot_process_compl(struct beiscsi_hba *phba,
--
2.30.2