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authorMark Johnston <markj@FreeBSD.org>2024-01-30 01:01:12 +0000
committerMark Johnston <markj@FreeBSD.org>2024-02-09 15:38:19 +0000
commit979e15bbf0cb35d6ef0b329507b2ef9507cfc6eb (patch)
treec437deebee54edd2eb7fd29b8b570e3565d79e3c
parent8b620483bbd60fbcc1374d195bb9eaf327434135 (diff)
downloadsrc-979e15bbf0cb35d6ef0b329507b2ef9507cfc6eb.tar.gz
src-979e15bbf0cb35d6ef0b329507b2ef9507cfc6eb.zip
scsi_cd: Maintain a periph reference during media checks
Otherwise nothing prevents the asynchronous media check state machine from running after the periph has been destroyed, which can result in a double free. Acquire the reference even when performing a synchronous check, since that doesn't hurt and keeps things simpler. PR: 276251 Reviewed by: imp Fixes: dd78f43259ef ("scsi_cd: make the media check asynchronous") MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D43525 (cherry picked from commit c961afe82596bdeb7e6a8626f02ddb181c8a24b6)
-rw-r--r--sys/cam/scsi/scsi_cd.c21
1 files changed, 10 insertions, 11 deletions
diff --git a/sys/cam/scsi/scsi_cd.c b/sys/cam/scsi/scsi_cd.c
index 76e413064781..d5406dc76f6f 100644
--- a/sys/cam/scsi/scsi_cd.c
+++ b/sys/cam/scsi/scsi_cd.c
@@ -2675,6 +2675,7 @@ cdmediaprobedone(struct cam_periph *periph)
softc->flags &= ~CD_FLAG_MEDIA_WAIT;
wakeup(&softc->toc);
}
+ cam_periph_release_locked(periph);
}
/*
@@ -2692,31 +2693,29 @@ cdcheckmedia(struct cam_periph *periph, bool do_wait)
softc = (struct cd_softc *)periph->softc;
error = 0;
- if ((do_wait != 0)
- && ((softc->flags & CD_FLAG_MEDIA_WAIT) == 0)) {
+ /* Released by cdmediaprobedone(). */
+ error = cam_periph_acquire(periph);
+ if (error != 0)
+ return (error);
+
+ if (do_wait)
softc->flags |= CD_FLAG_MEDIA_WAIT;
- }
if ((softc->flags & CD_FLAG_MEDIA_SCAN_ACT) == 0) {
softc->state = CD_STATE_MEDIA_PREVENT;
softc->flags |= CD_FLAG_MEDIA_SCAN_ACT;
xpt_schedule(periph, CAM_PRIORITY_NORMAL);
}
-
- if (do_wait == 0)
- goto bailout;
+ if (!do_wait)
+ return (0);
error = msleep(&softc->toc, cam_periph_mtx(periph), PRIBIO,"cdmedia",0);
- if (error != 0)
- goto bailout;
-
/*
* Check to see whether we have a valid size from the media. We
* may or may not have a valid TOC.
*/
- if ((softc->flags & CD_FLAG_VALID_MEDIA) == 0)
+ if (error == 0 && (softc->flags & CD_FLAG_VALID_MEDIA) == 0)
error = EINVAL;
-bailout:
return (error);
}