From f7068114d45ec55996b9040e98111afa56e010fe Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 21 May 2018 12:21:14 -0600 Subject: sr: pass down correctly sized SCSI sense buffer We're casting the CDROM layer request_sense to the SCSI sense buffer, but the former is 64 bytes and the latter is 96 bytes. As we generally allocate these on the stack, we end up blowing up the stack. Fix this by wrapping the scsi_execute() call with a properly sized sense buffer, and copying back the bits for the CDROM layer. Cc: stable@vger.kernel.org Reported-by: Piotr Gabriel Kosinski Reported-by: Daniel Shapira Tested-by: Kees Cook Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Jens Axboe --- drivers/scsi/sr_ioctl.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c index 2a21f2d48592..35fab1e18adc 100644 --- a/drivers/scsi/sr_ioctl.c +++ b/drivers/scsi/sr_ioctl.c @@ -188,9 +188,13 @@ int sr_do_ioctl(Scsi_CD *cd, struct packet_command *cgc) struct scsi_device *SDev; struct scsi_sense_hdr sshdr; int result, err = 0, retries = 0; + unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE], *senseptr = NULL; SDev = cd->device; + if (cgc->sense) + senseptr = sense_buffer; + retry: if (!scsi_block_when_processing_errors(SDev)) { err = -ENODEV; @@ -198,10 +202,12 @@ int sr_do_ioctl(Scsi_CD *cd, struct packet_command *cgc) } result = scsi_execute(SDev, cgc->cmd, cgc->data_direction, - cgc->buffer, cgc->buflen, - (unsigned char *)cgc->sense, &sshdr, + cgc->buffer, cgc->buflen, senseptr, &sshdr, cgc->timeout, IOCTL_RETRIES, 0, 0, NULL); + if (cgc->sense) + memcpy(cgc->sense, sense_buffer, sizeof(*cgc->sense)); + /* Minimal error checking. Ignore cases we know about, and report the rest. */ if (driver_byte(result) != 0) { switch (sshdr.sense_key) { -- cgit v1.2.3 From eedffa28c9b00ca2dcb4d541b5a530f4c917052d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 21 May 2018 14:35:03 -0400 Subject: loop: clear wb_err in bd_inode when detaching backing file When a loop block device encounters a writeback error, that error will get propagated to the bd_inode's wb_err field. If we then detach the backing file from it, attach another and fsync it, we'll get back the writeback error that we had from the previous backing file. This is a bit of a grey area as POSIX doesn't cover loop devices, but it is somewhat counterintuitive. If we detach a backing file from the loopdev while there are still unreported errors, take it as a sign that we're no longer interested in the previous file, and clear out the wb_err in the loop blockdev. Reported-and-Tested-by: Theodore Y. Ts'o Signed-off-by: Jeff Layton Signed-off-by: Jens Axboe --- drivers/block/loop.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 5d4e31655d96..55cf554bc914 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1068,6 +1068,7 @@ static int loop_clr_fd(struct loop_device *lo) if (bdev) { bdput(bdev); invalidate_bdev(bdev); + bdev->bd_inode->i_mapping->wb_err = 0; } set_capacity(lo->lo_disk, 0); loop_sysfs_exit(lo); -- cgit v1.2.3