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authorNicolin Chen <nicolinc@nvidia.com>2024-02-22 13:23:45 -0800
committerJason Gunthorpe <jgg@nvidia.com>2024-02-26 16:58:11 -0400
commitaeb004c0cd6958e910123a1607634401009c9539 (patch)
treef7716b45546c09ab19bb167cd04d0beeeaf9a737
parentd206a76d7d2726f3b096037f2079ce0bd3ba329b (diff)
iommufd: Fix iopt_access_list_id overwrite bug
Syzkaller reported the following WARN_ON: WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360 Call Trace: iommufd_access_change_ioas+0x2fe/0x4e0 iommufd_access_destroy_object+0x50/0xb0 iommufd_object_remove+0x2a3/0x490 iommufd_object_destroy_user iommufd_access_destroy+0x71/0xb0 iommufd_test_staccess_release+0x89/0xd0 __fput+0x272/0xb50 __fput_sync+0x4b/0x60 __do_sys_close __se_sys_close __x64_sys_close+0x8b/0x110 do_syscall_x64 The mismatch between the access pointer in the list and the passed-in pointer is resulting from an overwrite of access->iopt_access_list_id, in iopt_add_access(). Called from iommufd_access_change_ioas() when xa_alloc() succeeds but iopt_calculate_iova_alignment() fails. Add a new_id in iopt_add_access() and only update iopt_access_list_id when returning successfully. Cc: stable@vger.kernel.org Fixes: 9227da7816dd ("iommufd: Add iommufd_access_change_ioas(_id) helpers") Link: https://lore.kernel.org/r/2dda7acb25b8562ec5f1310de828ef5da9ef509c.1708636627.git.nicolinc@nvidia.com Reported-by: Jason Gunthorpe <jgg@nvidia.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
-rw-r--r--drivers/iommu/iommufd/io_pagetable.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 504ac1b01b2d..05fd9d3abf1b 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -1330,20 +1330,23 @@ out_unlock:
int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access)
{
+ u32 new_id;
int rc;
down_write(&iopt->domains_rwsem);
down_write(&iopt->iova_rwsem);
- rc = xa_alloc(&iopt->access_list, &access->iopt_access_list_id, access,
- xa_limit_16b, GFP_KERNEL_ACCOUNT);
+ rc = xa_alloc(&iopt->access_list, &new_id, access, xa_limit_16b,
+ GFP_KERNEL_ACCOUNT);
+
if (rc)
goto out_unlock;
rc = iopt_calculate_iova_alignment(iopt);
if (rc) {
- xa_erase(&iopt->access_list, access->iopt_access_list_id);
+ xa_erase(&iopt->access_list, new_id);
goto out_unlock;
}
+ access->iopt_access_list_id = new_id;
out_unlock:
up_write(&iopt->iova_rwsem);