Date: Thu, 25 Oct 2018 14:53:24 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r339719 - stable/12/sys/dev/sound/midi Message-ID: <201810251453.w9PErOdU057660@repo.freebsd.org>
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Author: hselasky Date: Thu Oct 25 14:53:24 2018 New Revision: 339719 URL: https://svnweb.freebsd.org/changeset/base/339719 Log: MFC r339582: Drop sequencer mutex around uiomove() and make sure we don't move more bytes than is available, else a panic might happen. Found by: Peter Holm <peter@holm.cc> Approved by: re (rgrimes) Sponsored by: Mellanox Technologies Modified: stable/12/sys/dev/sound/midi/sequencer.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/dev/sound/midi/sequencer.c ============================================================================== --- stable/12/sys/dev/sound/midi/sequencer.c Thu Oct 25 14:38:03 2018 (r339718) +++ stable/12/sys/dev/sound/midi/sequencer.c Thu Oct 25 14:53:24 2018 (r339719) @@ -921,7 +921,9 @@ mseq_read(struct cdev *i_dev, struct uio *uio, int iof SEQ_DEBUG(8, printf("midiread: uiomove cc=%d\n", used)); MIDIQ_DEQ(scp->in_q, buf, used); + mtx_unlock(&scp->seq_lock); retval = uiomove(buf, used, uio); + mtx_lock(&scp->seq_lock); if (retval) goto err1; } @@ -996,7 +998,9 @@ mseq_write(struct cdev *i_dev, struct uio *uio, int io retval = ENXIO; goto err0; } + mtx_unlock(&scp->seq_lock); retval = uiomove(event, used, uio); + mtx_lock(&scp->seq_lock); if (retval) goto err0; @@ -1034,7 +1038,9 @@ mseq_write(struct cdev *i_dev, struct uio *uio, int io SEQ_DEBUG(2, printf("seq_write: SEQ_FULLSIZE flusing buffer.\n")); while (uio->uio_resid > 0) { - retval = uiomove(event, EV_SZ, uio); + mtx_unlock(&scp->seq_lock); + retval = uiomove(event, MIN(EV_SZ, uio->uio_resid), uio); + mtx_lock(&scp->seq_lock); if (retval) goto err0; @@ -1045,6 +1051,7 @@ mseq_write(struct cdev *i_dev, struct uio *uio, int io } retval = EINVAL; if (ev_code >= 128) { + int error; /* * Some sort of an extended event. The size is eight @@ -1054,7 +1061,13 @@ mseq_write(struct cdev *i_dev, struct uio *uio, int io SEQ_DEBUG(2, printf("seq_write: invalid level two event %x.\n", ev_code)); goto err0; } - if (uiomove((caddr_t)&event[4], 4, uio)) { + mtx_unlock(&scp->seq_lock); + if (uio->uio_resid < 4) + error = EINVAL; + else + error = uiomove((caddr_t)&event[4], 4, uio); + mtx_lock(&scp->seq_lock); + if (error) { SEQ_DEBUG(2, printf("seq_write: user memory mangled?\n")); goto err0;
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