From: Qasim Ijaz <qasdev00@gmail.com> stable inclusion from stable-v6.6.76 commit 38ac76fc06bc6826a3e4b12a98efbe98432380a9 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBPBI4 CVE: CVE-2025-21724 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit e24c1551059268b37f6f40639883eafb281b8b9c ] Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index() where shifting the constant "1" (of type int) by bitmap->mapped.pgshift (an unsigned long value) could result in undefined behavior. The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds 31 (e.g., pgshift = 63) the shift operation overflows, as the result cannot be represented in a 32-bit type. To resolve this, the constant is updated to "1UL", promoting it to an unsigned long type to match the operand's type. Fixes: 58ccf0190d19 ("vfio: Add an IOVA bitmap support") Link: https://patch.msgid.link/r/20250113223820.10713-1-qasdev00@gmail.com Reported-by: syzbot <syzbot+85992ace37d5b7b51635@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=85992ace37d5b7b51635 Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: drivers/iommu/iommufd/iova_bitmap.c drivers/vfio/iova_bitmap.c [Context conflicts] Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> --- drivers/iommu/iommufd/iova_bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/iommufd/iova_bitmap.c b/drivers/iommu/iommufd/iova_bitmap.c index ca5a1757adcd..9527db8d7ba1 100644 --- a/drivers/iommu/iommufd/iova_bitmap.c +++ b/drivers/iommu/iommufd/iova_bitmap.c @@ -130,7 +130,7 @@ struct iova_bitmap { static unsigned long iova_bitmap_offset_to_index(struct iova_bitmap *bitmap, unsigned long iova) { - unsigned long pgsize = 1 << bitmap->mapped.pgshift; + unsigned long pgsize = 1UL << bitmap->mapped.pgshift; return iova / (BITS_PER_TYPE(*bitmap->bitmap) * pgsize); } -- 2.20.1