From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

mainline inclusion from mainline-v6.10-rc1 commit 8ee1b439b1540ae543149b15a2a61b9dff937d91 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA7D3E CVE: CVE-2024-38635

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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For some reason, we add an offset to the PDI, presumably to skip the PDI0 and PDI1 which are reserved for BPT.

This code is however completely wrong and leads to an out-of-bounds access. We were just lucky so far since we used only a couple of PDIs and remained within the PDI array bounds.

A Fixes: tag is not provided since there are no known platforms where the out-of-bounds would be accessed, and the initial code had problems as well.

A follow-up patch completely removes this useless offset.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com Link: https://lore.kernel.org/r/20240326090122.1051806-2-yung-chuan.liao@linux.int... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Zhang Zekun zhangzekun11@huawei.com --- drivers/soundwire/cadence_master.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 18e7d158fcca..d3e9cd3faadf 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1698,7 +1698,7 @@ struct sdw_cdns_pdi *sdw_cdns_alloc_pdi(struct sdw_cdns *cdns,

/* check if we found a PDI, else find in bi-directional */ if (!pdi) - pdi = cdns_find_pdi(cdns, 2, stream->num_bd, stream->bd, + pdi = cdns_find_pdi(cdns, 0, stream->num_bd, stream->bd, dai_id);

if (pdi) {