From 2724138b2f7f6299812b3404e23b124304834759 Mon Sep 17 00:00:00 2001 From: Deepanshu Kartikey Date: Sat, 24 Jan 2026 18:52:14 +0530 Subject: [PATCH] iommufd: Initialize batch->kind in batch_clear() KMSAN reported an uninitialized value when batch_add_pfn_num() reads batch->kind. This occurs because batch_clear() does not initialize the kind field. When batch_add_pfn_num() checks "if (batch->kind != kind)", it reads this uninitialized value, triggering KMSAN warnings. However the algorithm is fine with any value in kind at this point as the batch is always empty and it always corrects kind if wrong. Initialize batch->kind to zero in batch_clear() to silence the KMSAN warning. Link: https://patch.msgid.link/r/20260124132214.624041-1-kartikey406@gmail.com Reported-by: syzbot+df28076a30d726933015@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=df28076a30d726933015 Fixes: f394576eb11db ("iommufd: PFN handling for iopt_pages") Tested-by: syzbot+df28076a30d726933015@syzkaller.appspotmail.com Signed-off-by: Deepanshu Kartikey Reviewed-by: Kevin Tian Tested-by: syzbot+a0c841e02f328005bbcc@syzkaller.appspotmail.com Reported-by: syzbot+a0c841e02f328005bbcc@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/pages.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index dbe51ecb9a20..f606148920fa 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -289,6 +289,7 @@ static void batch_clear(struct pfn_batch *batch) batch->end = 0; batch->pfns[0] = 0; batch->npfns[0] = 0; + batch->kind = 0; } /*