diff options
Diffstat (limited to 'bz1471302.patch')
| -rw-r--r-- | bz1471302.patch | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/bz1471302.patch b/bz1471302.patch new file mode 100644 index 000000000..0a1325e78 --- /dev/null +++ b/bz1471302.patch @@ -0,0 +1,81 @@ +From: Johannes Thumshirn <jthumshirn@suse.de> +Subject: Re: [REGRESSION] 28676d869bbb (scsi: sg: check for valid direction + before starting the request) breaks mtx tape library control +To: Jason L Tibbitts III <tibbs@math.uh.edu> +Cc: Doug Gilbert <dgilbert@interlog.com>, linux-scsi@vger.kernel.org, + linux-kernel@vger.kernel.org, dvyukov@google.com, hare@suse.com, + hch@lst.de, martin.petersen@oracle.com +Date: Wed, 26 Jul 2017 09:39:34 +0200 (6 hours, 57 minutes ago) + +On Tue, Jul 25, 2017 at 01:25:07PM -0500, Jason L Tibbitts III wrote: +> >>>>> "JT" == Johannes Thumshirn <jthumshirn@suse.de> writes: +> ioctl(3, SG_IO, {interface_id='S', dxfer_direction=SG_DXFER_TO_DEV, cmd_len=12, cmdp="\xa5\x00\x00\x00\x00\x01\x03\xe9\x00\x00\x00\x00", mx_sb_len=20, iovec_count=0, dxfer_len=0, timeout=300000, flags=0, dxferp=NULL, status=0, masked_status=0, msg_status=0, sb_len_wr=0, sbp="", host_status=0, driver_status=0, resid=0, duration=0, info=0}) = -1 EINVAL (Invalid argument) + +[...] + case SG_DXFER_TO_DEV: + case SG_DXFER_TO_FROM_DEV: + if (!hp->dxferp) + return false; + return true; + +So here we go, dxfer_direction is SG_DXFER_TO_DEV, dxfer_len is 0 and dxferp +is NULL. We bail out because dxferp is NULL here. + +I only looked at sg_write() and not sg_new_write() which is called by the +SG_IO path not the fops->write() path. + +It's probably best to just check for dxfer_len <= 2^28 to be valid as Doug +suggested: + +diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c +index 4fe606b000b4..d7ff71e0c85c 100644 +--- a/drivers/scsi/sg.c ++++ b/drivers/scsi/sg.c +@@ -751,29 +751,6 @@ 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) +@@ -800,7 +771,7 @@ 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)) ++ if (hp->dxfer_len >= SZ_256M) + return -EINVAL; + + k = sg_start_req(srp, cmnd); + +-- +Johannes Thumshirn Storage +jthumshirn@suse.de +49 911 74053 689 +SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg +GF: Felix Imendörffer, Jane Smithard, Graham Norton +HRB 21284 (AG Nürnberg) +Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 + |