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| author | Mark Johnston <markj@FreeBSD.org> | 2024-01-30 01:01:12 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2024-01-30 14:24:55 +0000 |
| commit | c961afe82596bdeb7e6a8626f02ddb181c8a24b6 (patch) | |
| tree | 467e1425ca0119736631b831b66c4747729416ac | |
| parent | b1710124ff14f96db4c2a8fa37fc7c7b433fb176 (diff) | |
| download | src-c961afe82596bdeb7e6a8626f02ddb181c8a24b6.tar.gz src-c961afe82596bdeb7e6a8626f02ddb181c8a24b6.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
| -rw-r--r-- | sys/cam/scsi/scsi_cd.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/sys/cam/scsi/scsi_cd.c b/sys/cam/scsi/scsi_cd.c index 350b7f053ffd..6254596e75d3 100644 --- a/sys/cam/scsi/scsi_cd.c +++ b/sys/cam/scsi/scsi_cd.c @@ -2674,6 +2674,7 @@ cdmediaprobedone(struct cam_periph *periph) softc->flags &= ~CD_FLAG_MEDIA_WAIT; wakeup(&softc->toc); } + cam_periph_release_locked(periph); } /* @@ -2691,31 +2692,29 @@ 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); } |