Description: ALSA: seq: Fix racy pool initializations
References:
 https://marc.info/?l=alsa-devel&m=151859118611846&w=2
 http://mailman.alsa-project.org/pipermail/alsa-devel/2018-February/132026.html
Notes:
 bwh> There are two later related fixes, commits d85739367c6d
 bwh> "ALSA: seq: Don't allow resizing pool in use" and 7bd800915677
 bwh> "ALSA: seq: More protection for concurrent write and ioctl races",
 bwh> which don't seem to have CVE IDs.
Bugs:
upstream: released (4.16-rc2) [d15d662e89fc667b90cd294b0eb45694e33144da]
4.9-upstream-stable: released (4.9.83) [869182f45e38e4c62722b20a5c6f4bc48b2e60c3]
3.16-upstream-stable: released (3.16.57) [1786e202fe5a52fe6d4026b9e40c6a824efce148]
3.2-upstream-stable: released (3.2.102) [b5c3d49b3d5889f334d519d7a4535a3bd8632d47]
sid: released (4.15.11-1)
4.9-stretch-security: released (4.9.88-1)
3.16-jessie-security: released (3.16.56-1) [bugfix/all/alsa-seq-fix-racy-pool-initializations.patch]
3.2-wheezy-security: released (3.2.101-1) [bugfix/all/alsa-seq-fix-racy-pool-initializations.patch]