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charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-2.01 / 50.00]; BAYES_HAM(-3.00)[99.99%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; TO_DN_SOME(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_RATELIMITED(0.00)[rspamd.com]; FREEMAIL_TO(0.00)[gmail.com]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCPT_COUNT_SEVEN(0.00)[7]; RCVD_VIA_SMTP_AUTH(0.00)[]; TAGGED_RCPT(0.00)[8fa95c41eafbc9d2ff6f]; DKIM_TRACE(0.00)[suse.de:+]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,suse.com:email,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns] X-Rspamd-Queue-Id: 30A0E6A8FE X-Spam-Flag: NO X-Spam-Score: -2.01 X-Spam-Level: On Fri, 24 Apr 2026 14:48:41 +0200, Cássio Gabriel wrote: > > loopback_check_format() may stop the capture side when playback starts > with parameters that no longer match a running capture stream. Commit > 826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved > the peer lookup under cable->lock, but the actual snd_pcm_stop() still > runs after dropping that lock. > > A concurrent close can clear the capture entry from cable->streams[] and > detach or free its runtime while the playback trigger path still holds a > stale peer substream pointer. > > Keep a per-cable count of in-flight peer stops before dropping > cable->lock, and make free_cable() wait for those stops before > detaching the runtime. This preserves the existing behavior while > making the peer runtime lifetime explicit. > > Reported-by: syzbot+8fa95c41eafbc9d2ff6f@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=8fa95c41eafbc9d2ff6f > Fixes: 597603d615d2 ("ALSA: introduce the snd-aloop module for the PCM loopback") > Cc: stable@vger.kernel.org > Suggested-by: Takashi Iwai > Signed-off-by: Cássio Gabriel Applied now. Thanks. Takashi