diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2025-12-16 11:53:40 -0400 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2025-12-16 11:53:40 -0400 |
| commit | e6a973af11135439de32ece3b9cbe3bfc043bea8 (patch) | |
| tree | 51fccb4649a80f9c0f9693ca8fd2e0dc5744366f | |
| parent | b80fab281349f107a07e841eb412a86e2877ae88 (diff) | |
iommufd/selftest: Check for overflow in IOMMU_TEST_OP_ADD_RESERVED
syzkaller found it could overflow math in the test infrastructure and
cause a WARN_ON by corrupting the reserved interval tree. This only
effects test kernels with CONFIG_IOMMUFD_TEST.
Validate the user input length in the test ioctl.
Fixes: f4b20bb34c83 ("iommufd: Add kernel support for testing iommufd")
Link: https://patch.msgid.link/r/0-v1-cd99f6049ba5+51-iommufd_syz_add_resv_jgg@nvidia.com
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Reported-by: syzbot+57fdb0cf6a0c5d1f15a2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69368129.a70a0220.38f243.008f.GAE@google.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
| -rw-r--r-- | drivers/iommu/iommufd/selftest.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index 86446e153794..550ff36dec3a 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -1184,14 +1184,20 @@ static int iommufd_test_add_reserved(struct iommufd_ucmd *ucmd, unsigned int mockpt_id, unsigned long start, size_t length) { + unsigned long last; struct iommufd_ioas *ioas; int rc; + if (!length) + return -EINVAL; + if (check_add_overflow(start, length - 1, &last)) + return -EOVERFLOW; + ioas = iommufd_get_ioas(ucmd->ictx, mockpt_id); if (IS_ERR(ioas)) return PTR_ERR(ioas); down_write(&ioas->iopt.iova_rwsem); - rc = iopt_reserve_iova(&ioas->iopt, start, start + length - 1, NULL); + rc = iopt_reserve_iova(&ioas->iopt, start, last, NULL); up_write(&ioas->iopt.iova_rwsem); iommufd_put_object(ucmd->ictx, &ioas->obj); return rc; |