From c7a841f3aca469187db76842676951a672fd27d1 Mon Sep 17 00:00:00 2001 From: James Smart Date: Sun, 14 Nov 2010 11:12:04 -0500 Subject: [PATCH] [SCSI] bsg: correct fault if queue object removed while dev_t open This patch corrects an issue in bsg that results in a general protection fault if an LLD is removed while an application is using an open file handle to a bsg device, and the application issues an ioctl. The fault occurs because the class_dev is NULL, having been cleared in bsg_unregister_queue() when the driver was removed. With this patch, a check is made for the class_dev, and the application will receive ENXIO if the related object is gone. Signed-off-by: Carl Lajeunesse Signed-off-by: James Smart Signed-off-by: James Bottomley --- block/bsg.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/bsg.c b/block/bsg.c index f20d6a789d48..0c8b64a16484 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -250,6 +250,14 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, int ret, rw; unsigned int dxfer_len; void *dxferp = NULL; + struct bsg_class_device *bcd = &q->bsg_dev; + + /* if the LLD has been removed then the bsg_unregister_queue will + * eventually be called and the class_dev was freed, so we can no + * longer use this request_queue. Return no such address. + */ + if (!bcd->class_dev) + return ERR_PTR(-ENXIO); dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp, hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp, -- 2.20.1