From: Cássio Gabriel Date: Mon, 25 May 2026 14:16:09 +0000 (-0300) Subject: ALSA: seq: Remove arbitrary prioq insertion limit X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3fcc84f1f8d28cc1966b859cef33c858ff531766;p=thirdparty%2Flinux.git ALSA: seq: Remove arbitrary prioq insertion limit The sequencer priority queue insertion path uses a hardcoded traversal limit of 10000 entries. The value is intended to catch a corrupted list, but it also becomes a real limit for valid queues. The event pool limit is per client, while a sequencer queue can be shared by multiple clients. A queue can therefore legitimately contain more than 10000 events. In that case, inserting an event that has to be placed past the arbitrary limit fails with -EINVAL. Use the queue's own cell count as the traversal bound instead. This keeps the protection against inconsistent list accounting or cyclic lists without rejecting valid large queues. Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260525-alsa-seq-prioq-limit-v1-1-16c348df5ff7@gmail.com Signed-off-by: Takashi Iwai --- diff --git a/sound/core/seq/seq_prioq.c b/sound/core/seq/seq_prioq.c index 25c0ed8f9f0f..d5bad1c585f6 100644 --- a/sound/core/seq/seq_prioq.c +++ b/sound/core/seq/seq_prioq.c @@ -132,7 +132,7 @@ int snd_seq_prioq_cell_in(struct snd_seq_prioq * f, struct snd_seq_event_cell * cell) { struct snd_seq_event_cell *cur, *prev; - int count; + int remaining; int prior; if (snd_BUG_ON(!f || !cell)) @@ -162,10 +162,16 @@ int snd_seq_prioq_cell_in(struct snd_seq_prioq * f, prev = NULL; /* previous cell */ cur = f->head; /* cursor */ - count = 10000; /* FIXME: enough big, isn't it? */ + remaining = f->cells; while (cur != NULL) { /* compare timestamps */ int rel = compare_timestamp_rel(&cell->event, &cur->event); + + if (remaining-- <= 0) { + pr_err("ALSA: seq: inconsistent prioq cell count\n"); + return -EINVAL; + } + if (rel < 0) /* new cell has earlier schedule time, */ break; @@ -176,10 +182,6 @@ int snd_seq_prioq_cell_in(struct snd_seq_prioq * f, /* move cursor to next cell */ prev = cur; cur = cur->next; - if (! --count) { - pr_err("ALSA: seq: cannot find a pointer.. infinite loop?\n"); - return -EINVAL; - } } /* insert it before cursor */