From 1ae948fa4f00f3a2823e7cb19a3049ef27dd6947 Mon Sep 17 00:00:00 2001 From: Brian King Date: Tue, 29 Aug 2017 10:00:29 -0500 Subject: [PATCH] scsi: aacraid: Fix command send race condition This fixes a potential race condition observed on Power systems. Several places throughout the aacraid driver call aac_fib_send or similar to send a command to the aacraid adapter, then check the return code to determine if the command was actually sent to the adapter, then update the phase field in the scsi command scratch pad area to track that the firmware now owns this command. However, there is nothing that ensures that by the time the aac_fib_send function returns and we go to write to the scsi command, that the command hasn't already completed and the scsi command has been freed. This was causing random crashes in the TCP stack which was tracked down to be caused by memory that had been a struct request + scsi_cmnd being now used for an skbuff. Memory poisoning was enabled in the kernel to debug this which showed that the last owner of the memory that had been freed was aacraid and that it was a struct request. The memory that was corrupted was the exact data pattern of AAC_OWNER_FIRMWARE and it was at the same offset that aacraid writes, which is scsicmd->SCp.phase. The patch below resolves this issue. Cc: Signed-off-by: Brian King Tested-by: Wen Xiong Reviewed-by: Dave Carroll Signed-off-by: Martin K. Petersen --- drivers/scsi/aacraid/aachba.c | 54 ++++++++++++++--------------------- 1 file changed, 21 insertions(+), 33 deletions(-) diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c index a1a2c71e1626..b051d97af468 100644 --- a/drivers/scsi/aacraid/aachba.c +++ b/drivers/scsi/aacraid/aachba.c @@ -594,6 +594,7 @@ static int aac_get_container_name(struct scsi_cmnd * scsicmd) aac_fib_init(cmd_fibcontext); dinfo = (struct aac_get_name *) fib_data(cmd_fibcontext); + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; dinfo->command = cpu_to_le32(VM_ContainerConfig); dinfo->type = cpu_to_le32(CT_READ_NAME); @@ -611,10 +612,8 @@ static int aac_get_container_name(struct scsi_cmnd * scsicmd) /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_get_container_name: aac_fib_send failed with status: %d.\n", status); aac_fib_complete(cmd_fibcontext); @@ -725,6 +724,7 @@ static void _aac_probe_container1(void * context, struct fib * fibptr) dinfo->count = cpu_to_le32(scmd_id(scsicmd)); dinfo->type = cpu_to_le32(FT_FILESYS); + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_fib_send(ContainerCommand, fibptr, @@ -736,9 +736,7 @@ static void _aac_probe_container1(void * context, struct fib * fibptr) /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; - else if (status < 0) { + if (status < 0 && status != -EINPROGRESS) { /* Inherit results from VM_NameServe, if any */ dresp->status = cpu_to_le32(ST_OK); _aac_probe_container2(context, fibptr); @@ -766,6 +764,7 @@ static int _aac_probe_container(struct scsi_cmnd * scsicmd, int (*callback)(stru dinfo->count = cpu_to_le32(scmd_id(scsicmd)); dinfo->type = cpu_to_le32(FT_FILESYS); scsicmd->SCp.ptr = (char *)callback; + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_fib_send(ContainerCommand, fibptr, @@ -777,10 +776,9 @@ static int _aac_probe_container(struct scsi_cmnd * scsicmd, int (*callback)(stru /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } + if (status < 0) { scsicmd->SCp.ptr = NULL; aac_fib_complete(fibptr); @@ -1126,6 +1124,7 @@ static int aac_get_container_serial(struct scsi_cmnd * scsicmd) dinfo->command = cpu_to_le32(VM_ContainerConfig); dinfo->type = cpu_to_le32(CT_CID_TO_32BITS_UID); dinfo->cid = cpu_to_le32(scmd_id(scsicmd)); + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_fib_send(ContainerCommand, cmd_fibcontext, @@ -1138,10 +1137,8 @@ static int aac_get_container_serial(struct scsi_cmnd * scsicmd) /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_get_container_serial: aac_fib_send failed with status: %d.\n", status); aac_fib_complete(cmd_fibcontext); @@ -2335,16 +2332,14 @@ static int aac_read(struct scsi_cmnd * scsicmd) * Alocate and initialize a Fib */ cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd); - + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_adapter_read(cmd_fibcontext, scsicmd, lba, count); /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_read: aac_fib_send failed with status: %d.\n", status); /* @@ -2429,16 +2424,14 @@ static int aac_write(struct scsi_cmnd * scsicmd) * Allocate and initialize a Fib then setup a BlockWrite command */ cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd); - + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_adapter_write(cmd_fibcontext, scsicmd, lba, count, fua); /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_write: aac_fib_send failed with status: %d\n", status); /* @@ -2588,6 +2581,7 @@ static int aac_synchronize(struct scsi_cmnd *scsicmd) synchronizecmd->cid = cpu_to_le32(scmd_id(scsicmd)); synchronizecmd->count = cpu_to_le32(sizeof(((struct aac_synchronize_reply *)NULL)->data)); + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; /* * Now send the Fib to the adapter @@ -2603,10 +2597,8 @@ static int aac_synchronize(struct scsi_cmnd *scsicmd) /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_synchronize: aac_fib_send failed with status: %d.\n", status); @@ -2666,6 +2658,7 @@ static int aac_start_stop(struct scsi_cmnd *scsicmd) pmcmd->cid = cpu_to_le32(sdev_id(sdev)); pmcmd->parm = (scsicmd->cmnd[1] & 1) ? cpu_to_le32(CT_PM_UNIT_IMMEDIATE) : 0; + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; /* * Now send the Fib to the adapter @@ -2681,10 +2674,8 @@ static int aac_start_stop(struct scsi_cmnd *scsicmd) /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } aac_fib_complete(cmd_fibcontext); aac_fib_free(cmd_fibcontext); @@ -3692,16 +3683,14 @@ static int aac_send_srb_fib(struct scsi_cmnd* scsicmd) * Allocate and initialize a Fib then setup a BlockWrite command */ cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd); - + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_adapter_scsi(cmd_fibcontext, scsicmd); /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } printk(KERN_WARNING "aac_srb: aac_fib_send failed with status: %d\n", status); aac_fib_complete(cmd_fibcontext); @@ -3739,15 +3728,14 @@ static int aac_send_hba_fib(struct scsi_cmnd *scsicmd) if (!cmd_fibcontext) return -1; + scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; status = aac_adapter_hba(cmd_fibcontext, scsicmd); /* * Check that the command queued to the controller */ - if (status == -EINPROGRESS) { - scsicmd->SCp.phase = AAC_OWNER_FIRMWARE; + if (status == -EINPROGRESS) return 0; - } pr_warn("aac_hba_cmd_req: aac_fib_send failed with status: %d\n", status); -- 2.20.1