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| author |   Akinobu Mita <akinobu.mita@gmail.com> | 2014-06-02 22:56:46 +0900 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2014-07-17 22:07:29 +0200 |
| commit | 46f69e6a6bbbf3858617c8729e31895846c15a79 (patch) | |
| tree | 08a5ee77461f9b1899d43fd5c74aea6527be614e /drivers/scsi/sg.c | |
| parent | scsi: remove two cancel_delayed_work() calls from the mid-layer (diff) | |
| download | linux-dev-46f69e6a6bbbf3858617c8729e31895846c15a79.tar.xz linux-dev-46f69e6a6bbbf3858617c8729e31895846c15a79.zip | |
sg: prevent integer overflow when converting from sectors to bytes
This prevents integer overflow when converting the request queue's
max_sectors from sectors to bytes. However, this is a preparation for
extending the data type of max_sectors in struct Scsi_Host and
scsi_host_template. So, it is impossible to happen this integer
overflow for now, because SCSI low-level drivers can not specify
max_sectors greater than 0xffff due to the data type limitation.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/sg.c')
| -rw-r--r-- | drivers/scsi/sg.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 53268aaba559..8f952af48322 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -806,6 +806,15 @@ static int srp_done(Sg_fd *sfp, Sg_request *srp) return ret; } +static int max_sectors_bytes(struct request_queue *q) +{ + unsigned int max_sectors = queue_max_sectors(q); + + max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9); + + return max_sectors << 9; +} + static long sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) { @@ -945,7 +954,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) if (val < 0) return -EINVAL; val = min_t(int, val, - queue_max_sectors(sdp->device->request_queue) * 512); + max_sectors_bytes(sdp->device->request_queue)); if (val != sfp->reserve.bufflen) { if (sg_res_in_use(sfp) || sfp->mmap_called) return -EBUSY; @@ -955,7 +964,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return 0; case SG_GET_RESERVED_SIZE: val = min_t(int, sfp->reserve.bufflen, - queue_max_sectors(sdp->device->request_queue) * 512); + max_sectors_bytes(sdp->device->request_queue)); return put_user(val, ip); case SG_SET_COMMAND_Q: result = get_user(val, ip); @@ -1095,7 +1104,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return -ENODEV; return scsi_ioctl(sdp->device, cmd_in, p); case BLKSECTGET: - return put_user(queue_max_sectors(sdp->device->request_queue) * 512, + return put_user(max_sectors_bytes(sdp->device->request_queue), ip); case BLKTRACESETUP: return blk_trace_setup(sdp->device->request_queue, @@ -2085,7 +2094,7 @@ sg_add_sfp(Sg_device * sdp, int dev) sg_big_buff = def_reserved_size; bufflen = min_t(int, sg_big_buff, - queue_max_sectors(sdp->device->request_queue) * 512); + max_sectors_bytes(sdp->device->request_queue)); sg_build_reserve(sfp, bufflen); SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: bufflen=%d, k_use_sg=%d\n", sfp->reserve.bufflen, sfp->reserve.k_use_sg)); |