Messages in this thread | | | Date | Fri, 5 Nov 2021 12:39:47 +0300 | From | Dan Carpenter <> | Subject | [luxis1999-dev-iommu:iommufd-vfio-v5.16-rc1 21/32] drivers/iommufd/iommufd.c:163 iommufd_ioas_alloc() error: dereferencing freed memory 'ioas' |
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tree: https://github.com/luxis1999/dev-iommu iommufd-vfio-v5.16-rc1 head: 0c6c7bdb5b3f7d4c8e6b03d34a59ac6bf3d02539 commit: a13cbd0a0fca96a74a170239e2e88e68940331c3 [21/32] iommufd: Add IOMMU_IOAS_ALLOC/FREE config: x86_64-randconfig-m001-20211105 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings: drivers/iommufd/iommufd.c:163 iommufd_ioas_alloc() error: dereferencing freed memory 'ioas'
vim +/ioas +163 drivers/iommufd/iommufd.c
a13cbd0a0fca96 Liu Yi L 2021-10-31 126 static int iommufd_ioas_alloc(struct iommufd_ctx *ictx, unsigned long arg) a13cbd0a0fca96 Liu Yi L 2021-10-31 127 { a13cbd0a0fca96 Liu Yi L 2021-10-31 128 struct iommu_ioas_alloc req; a13cbd0a0fca96 Liu Yi L 2021-10-31 129 struct iommufd_ioas *ioas; a13cbd0a0fca96 Liu Yi L 2021-10-31 130 unsigned long minsz; a13cbd0a0fca96 Liu Yi L 2021-10-31 131 int ret; a13cbd0a0fca96 Liu Yi L 2021-10-31 132 a13cbd0a0fca96 Liu Yi L 2021-10-31 133 minsz = offsetofend(struct iommu_ioas_alloc, addr_width); a13cbd0a0fca96 Liu Yi L 2021-10-31 134 a13cbd0a0fca96 Liu Yi L 2021-10-31 135 if (copy_from_user(&req, (void __user *)arg, minsz)) a13cbd0a0fca96 Liu Yi L 2021-10-31 136 return -EFAULT; a13cbd0a0fca96 Liu Yi L 2021-10-31 137 a13cbd0a0fca96 Liu Yi L 2021-10-31 138 if (req.argsz < minsz || !req.addr_width || a13cbd0a0fca96 Liu Yi L 2021-10-31 139 req.flags != IOMMU_IOAS_ENFORCE_SNOOP || a13cbd0a0fca96 Liu Yi L 2021-10-31 140 req.type != IOMMU_IOAS_TYPE_KERNEL_TYPE1V2) a13cbd0a0fca96 Liu Yi L 2021-10-31 141 return -EINVAL; a13cbd0a0fca96 Liu Yi L 2021-10-31 142 a13cbd0a0fca96 Liu Yi L 2021-10-31 143 ioas = kzalloc(sizeof(*ioas), GFP_KERNEL); a13cbd0a0fca96 Liu Yi L 2021-10-31 144 if (!ioas) a13cbd0a0fca96 Liu Yi L 2021-10-31 145 return -ENOMEM; a13cbd0a0fca96 Liu Yi L 2021-10-31 146 a13cbd0a0fca96 Liu Yi L 2021-10-31 147 /* only supports kernel managed I/O page table so far */ a13cbd0a0fca96 Liu Yi L 2021-10-31 148 ioas->type = IOMMU_IOAS_TYPE_KERNEL_TYPE1V2; a13cbd0a0fca96 Liu Yi L 2021-10-31 149 ioas->addr_width = req.addr_width; a13cbd0a0fca96 Liu Yi L 2021-10-31 150 /* only supports enforce snoop today */ a13cbd0a0fca96 Liu Yi L 2021-10-31 151 ioas->enforce_snoop = true; a13cbd0a0fca96 Liu Yi L 2021-10-31 152 ioas->ictx = ictx; a13cbd0a0fca96 Liu Yi L 2021-10-31 153 a13cbd0a0fca96 Liu Yi L 2021-10-31 154 refcount_set(&ioas->refs, 1); a13cbd0a0fca96 Liu Yi L 2021-10-31 155 a13cbd0a0fca96 Liu Yi L 2021-10-31 156 ret = xa_alloc(&ictx->ioas_xa, &ioas->ioas_id, ioas, a13cbd0a0fca96 Liu Yi L 2021-10-31 157 xa_limit_32b, GFP_KERNEL); a13cbd0a0fca96 Liu Yi L 2021-10-31 158 if (ret) a13cbd0a0fca96 Liu Yi L 2021-10-31 159 kfree(ioas);
Needs to return -ENOMEM here.
a13cbd0a0fca96 Liu Yi L 2021-10-31 160 a13cbd0a0fca96 Liu Yi L 2021-10-31 161 if (copy_to_user((void __user *)arg + minsz, a13cbd0a0fca96 Liu Yi L 2021-10-31 162 &ioas->ioas_id, sizeof(ioas->ioas_id))) { ^^^^^^^^^^^^^ Already freed.
a13cbd0a0fca96 Liu Yi L 2021-10-31 @163 xa_erase(&ictx->ioas_xa, ioas->ioas_id); a13cbd0a0fca96 Liu Yi L 2021-10-31 164 kfree(ioas); a13cbd0a0fca96 Liu Yi L 2021-10-31 165 ret = -EFAULT; a13cbd0a0fca96 Liu Yi L 2021-10-31 166 } a13cbd0a0fca96 Liu Yi L 2021-10-31 167 a13cbd0a0fca96 Liu Yi L 2021-10-31 168 return ret; a13cbd0a0fca96 Liu Yi L 2021-10-31 169 }
--- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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