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authorMatthew Auld <matthew.auld@intel.com>2024-04-12 14:31:45 +0300
committerLucas De Marchi <lucas.demarchi@intel.com>2024-04-17 16:03:13 +0300
commitca7c52ac7ad384bcf299d89482c45fec7cd00da9 (patch)
tree10a9a5828918ba85edacb318786c72431845836e /drivers
parent652ead9b746a63e4e79d7ad66d3edf0a8a5b0c2f (diff)
downloadlinux-ca7c52ac7ad384bcf299d89482c45fec7cd00da9.tar.xz
drm/xe/vm: prevent UAF with asid based lookup
The asid is only erased from the xarray when the vm refcount reaches zero, however this leads to potential UAF since the xe_vm_get() only works on a vm with refcount != 0. Since the asid is allocated in the vm create ioctl, rather erase it when closing the vm, prior to dropping the potential last ref. This should also work when user closes driver fd without explicit vm destroy. Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1594 Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: <stable@vger.kernel.org> # v6.8+ Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240412113144.259426-4-matthew.auld@intel.com (cherry picked from commit 83967c57320d0d01ae512f10e79213f81e4bf594) Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/xe/xe_vm.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 62d1ef8867a8..3d4c8f342e21 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -1577,6 +1577,16 @@ void xe_vm_close_and_put(struct xe_vm *vm)
xe->usm.num_vm_in_fault_mode--;
else if (!(vm->flags & XE_VM_FLAG_MIGRATION))
xe->usm.num_vm_in_non_fault_mode--;
+
+ if (vm->usm.asid) {
+ void *lookup;
+
+ xe_assert(xe, xe->info.has_asid);
+ xe_assert(xe, !(vm->flags & XE_VM_FLAG_MIGRATION));
+
+ lookup = xa_erase(&xe->usm.asid_to_vm, vm->usm.asid);
+ xe_assert(xe, lookup == vm);
+ }
mutex_unlock(&xe->usm.lock);
for_each_tile(tile, xe, id)
@@ -1592,24 +1602,15 @@ static void vm_destroy_work_func(struct work_struct *w)
struct xe_device *xe = vm->xe;
struct xe_tile *tile;
u8 id;
- void *lookup;
/* xe_vm_close_and_put was not called? */
xe_assert(xe, !vm->size);
mutex_destroy(&vm->snap_mutex);
- if (!(vm->flags & XE_VM_FLAG_MIGRATION)) {
+ if (!(vm->flags & XE_VM_FLAG_MIGRATION))
xe_device_mem_access_put(xe);
- if (xe->info.has_asid && vm->usm.asid) {
- mutex_lock(&xe->usm.lock);
- lookup = xa_erase(&xe->usm.asid_to_vm, vm->usm.asid);
- xe_assert(xe, lookup == vm);
- mutex_unlock(&xe->usm.lock);
- }
- }
-
for_each_tile(tile, xe, id)
XE_WARN_ON(vm->pt_root[id]);