From 14497328b6a628cedafdd2df1bb8d3e9d1d5338f Mon Sep 17 00:00:00 2001 From: Yaniv Gardi Date: Mon, 1 Feb 2016 15:02:39 +0200 Subject: [PATCH] scsi: ufs: verify command tag validity A race condition appear to exist between request completion when scsi_done() is called to end the request and set the tag back to -1 (at blk_queue_end_tag() scsi_end_request), and scsi layer error handling which aborts the command and reuses it to request sense data. Sending the request sense is done with tag which was set to -1 and so it is invalid. Assert command tag passed from scsi layer is valid. Reviewed-by: Subhash Jadavani Reviewed-by: Dolev Raviv Signed-off-by: Gilad Broner Signed-off-by: Yaniv Gardi Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 7ae87c9c3496..8a34f61be679 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -190,6 +190,10 @@ static int ufshcd_config_pwr_mode(struct ufs_hba *hba, struct ufs_pa_layer_attr *desired_pwr_mode); static int ufshcd_change_power_mode(struct ufs_hba *hba, struct ufs_pa_layer_attr *pwr_mode); +static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag) +{ + return tag >= 0 && tag < hba->nutrs; +} static inline int ufshcd_enable_irq(struct ufs_hba *hba) { @@ -1309,6 +1313,12 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) hba = shost_priv(host); tag = cmd->request->tag; + if (!ufshcd_valid_tag(hba, tag)) { + dev_err(hba->dev, + "%s: invalid command tag %d: cmd=0x%p, cmd->request=0x%p", + __func__, tag, cmd, cmd->request); + BUG(); + } spin_lock_irqsave(hba->host->host_lock, flags); switch (hba->ufshcd_state) { @@ -3861,13 +3871,23 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) host = cmd->device->host; hba = shost_priv(host); tag = cmd->request->tag; + if (!ufshcd_valid_tag(hba, tag)) { + dev_err(hba->dev, + "%s: invalid command tag %d: cmd=0x%p, cmd->request=0x%p", + __func__, tag, cmd, cmd->request); + BUG(); + } ufshcd_hold(hba, false); + reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); /* If command is already aborted/completed, return SUCCESS */ - if (!(test_bit(tag, &hba->outstanding_reqs))) + if (!(test_bit(tag, &hba->outstanding_reqs))) { + dev_err(hba->dev, + "%s: cmd at tag %d already completed, outstanding=0x%lx, doorbell=0x%x\n", + __func__, tag, hba->outstanding_reqs, reg); goto out; + } - reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); if (!(reg & (1 << tag))) { dev_err(hba->dev, "%s: cmd was completed, but without a notifying intr, tag = %d", -- 2.20.1