6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Ujfalusi [ Upstream commit 746de48c3a250f0c264105dcbfcdf0c5001e970b ] When ch_count is smaller than blob->alh_cfg.device_count (e.g. a mono capture stream, such as a SmartMic, aggregated across multiple SDW links), step = ch_count / blob->alh_cfg.device_count truncates to 0. The subsequent GENMASK(step - 1, 0) then underflows step - 1 (u32) to UINT_MAX, causing GENMASK()'s internal shift to use an out-of-bounds exponent: UBSAN: shift-out-of-bounds in sound/soc/sof/ipc4-topology.c:2363:13 shift exponent 18446744069414584384 is too large for 64-bit type 'long unsigned int' Treat ch_count < device_count the same way as the existing "channels equal to output reference channels" case: apply the same ch_mask to every aggregated device instead of trying to split channels that can't be evenly divided. Fixes: 0390a102cc18 ("ASoC: SOF: ipc4-topology: use different channel mask for each sdw amp feedback") Cc: stable@vger.kernel.org Signed-off-by: Peter Ujfalusi Reviewed-by: Bard Liao Link: https://patch.msgid.link/20261008090130.15135-1-peter.ujfalusi@linux.intel.com Signed-off-by: Mark Brown [ sashal: Added a standalone guard around the mask calculation because the upstream playback conditional is absent. ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- sound/soc/sof/ipc4-topology.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) --- a/sound/soc/sof/ipc4-topology.c +++ b/sound/soc/sof/ipc4-topology.c @@ -2286,8 +2286,20 @@ sof_ipc4_prepare_copier_module(struct sn ch_map >>= 4; } - step = ch_count / blob->alh_cfg.device_count; - mask = GENMASK(step - 1, 0); + if (ch_count < blob->alh_cfg.device_count) { + /* + * When there are fewer channels than aggregated devices + * (e.g. a mono capture stream split across multiple links), + * set step = 0 to ensure all the ch_mask is applied to all + * alh mappings. + */ + mask = ch_mask; + step = 0; + } else { + step = ch_count / blob->alh_cfg.device_count; + mask = GENMASK(step - 1, 0); + } + /* * Set each gtw_cfg.node_id to blob->alh_cfg.mapping[] * for all widgets with the same stream name