From: Johannes Thumshirn <jthumshirn@xxxxxxx> [ Upstream commit 28676d869bbb5257b5f14c0c95ad3af3a7019dd5 ] Check for a valid direction before starting the request, otherwise we risk running into an assertion in the scsi midlayer checking for valid requests. [mkp: fixed typo] Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Link: http://www.spinics.net/lists/linux-scsi/msg104400.html Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Signed-off-by: Hannes Reinecke <hare@xxxxxxxx> Tested-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/scsi/sg.c | 46 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 0f0ff75755e0..27f92f4ea6bc 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -674,18 +674,14 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) * is a non-zero input_size, so emit a warning. */ if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) { - static char cmd[TASK_COMM_LEN]; - if (strcmp(current->comm, cmd)) { - printk_ratelimited(KERN_WARNING - "sg_write: data in/out %d/%d bytes " - "for SCSI command 0x%x-- guessing " - "data in;\n program %s not setting " - "count and/or reply_len properly\n", - old_hdr.reply_len - (int)SZ_SG_HEADER, - input_size, (unsigned int) cmnd[0], - current->comm); - strcpy(cmd, current->comm); - } + printk_ratelimited(KERN_WARNING + "sg_write: data in/out %d/%d bytes " + "for SCSI command 0x%x-- guessing " + "data in;\n program %s not setting " + "count and/or reply_len properly\n", + old_hdr.reply_len - (int)SZ_SG_HEADER, + input_size, (unsigned int) cmnd[0], + current->comm); } k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking); return (k < 0) ? k : count; @@ -764,6 +760,29 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, return count; } +static bool sg_is_valid_dxfer(sg_io_hdr_t *hp) +{ + switch (hp->dxfer_direction) { + case SG_DXFER_NONE: + if (hp->dxferp || hp->dxfer_len > 0) + return false; + return true; + case SG_DXFER_TO_DEV: + case SG_DXFER_FROM_DEV: + case SG_DXFER_TO_FROM_DEV: + if (!hp->dxferp || hp->dxfer_len == 0) + return false; + return true; + case SG_DXFER_UNKNOWN: + if ((!hp->dxferp && hp->dxfer_len) || + (hp->dxferp && hp->dxfer_len == 0)) + return false; + return true; + default: + return false; + } +} + static int sg_common_write(Sg_fd * sfp, Sg_request * srp, unsigned char *cmnd, int timeout, int blocking) @@ -784,6 +803,9 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) cmnd[0], (int) hp->cmd_len)); + if (!sg_is_valid_dxfer(hp)) + return -EINVAL; + k = sg_start_req(srp, cmnd); if (k) { SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp, -- 2.14.1