From 61006c540cbdedea83b05577dc7fb7fa18fe1276 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 19 Jan 2026 14:32:07 +0100 Subject: [PATCH] ALSA: ctxfi: Fix potential OOB access in audio mixer handling In the audio mixer handling code of ctxfi driver, the conf field is used as a kind of loop index, and it's referred in the index callbacks (amixer_index() and sum_index()). As spotted recently by fuzzers, the current code causes OOB access at those functions. | UBSAN: array-index-out-of-bounds in /build/reproducible-path/linux-6.17.8/sound/pci/ctxfi/ctamixer.c:347:48 | index 8 is out of range for type 'unsigned char [8]' After the analysis, the cause was found to be the lack of the proper (re-)initialization of conj field. This patch addresses those OOB accesses by adding the proper initializations of the loop indices. Reported-by: Salvatore Bonaccorso Tested-by: Karsten Hohmeier Closes: https://bugs.debian.org/1121535 Cc: Link: https://lore.kernel.org/all/aSk8KJI35H7gFru6@eldamar.lan/ Link: https://patch.msgid.link/20260119133212.189129-1-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/pci/ctxfi/ctamixer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/pci/ctxfi/ctamixer.c b/sound/pci/ctxfi/ctamixer.c index bb4658592636..c30162be27ee 100644 --- a/sound/pci/ctxfi/ctamixer.c +++ b/sound/pci/ctxfi/ctamixer.c @@ -205,6 +205,7 @@ static int amixer_rsc_init(struct amixer *amixer, /* Set amixer specific operations */ amixer->rsc.ops = &amixer_basic_rsc_ops; + amixer->rsc.conj = 0; amixer->ops = &amixer_ops; amixer->input = NULL; amixer->sum = NULL; @@ -367,6 +368,7 @@ static int sum_rsc_init(struct sum *sum, return err; sum->rsc.ops = &sum_basic_rsc_ops; + sum->rsc.conj = 0; return 0; } -- 2.47.3