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authorShuicheng Lin <shuicheng.lin@intel.com>2025-11-12 18:10:06 +0000
committerLucas De Marchi <lucas.demarchi@intel.com>2025-11-18 10:04:41 -0800
commitd52dea485cd3c98cfeeb474cf66cf95df2ab142f (patch)
tree84a2ddff297362a3d28d7cfc792ae25e49c984cd
parent6a23ae0a96a600d1d12557add110e0bb6e32730c (diff)
drm/xe: Prevent BIT() overflow when handling invalid prefetch region
If user provides a large value (such as 0x80) for parameter prefetch_mem_region_instance in vm_bind ioctl, it will cause BIT(prefetch_region) overflow as below: " ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/gpu/drm/xe/xe_vm.c:3414:7 shift exponent 128 is too large for 64-bit type 'long unsigned int' CPU: 8 UID: 0 PID: 53120 Comm: xe_exec_system_ Tainted: G W 6.18.0-rc1-lgci-xe-kernel+ #200 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: ASUS System Product Name/PRIME Z790-P WIFI, BIOS 0812 02/24/2023 Call Trace: <TASK> dump_stack_lvl+0xa0/0xc0 dump_stack+0x10/0x20 ubsan_epilogue+0x9/0x40 __ubsan_handle_shift_out_of_bounds+0x10e/0x170 ? mutex_unlock+0x12/0x20 xe_vm_bind_ioctl.cold+0x20/0x3c [xe] ... " Fix it by validating prefetch_region before the BIT() usage. v2: Add Closes and Cc stable kernels. (Matt) Reported-by: Koen Koning <koen.koning@intel.com> Reported-by: Peter Senna Tschudin <peter.senna@linux.intel.com> Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6478 Cc: <stable@vger.kernel.org> # v6.8+ Reviewed-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Link: https://patch.msgid.link/20251112181005.2120521-2-shuicheng.lin@intel.com (cherry picked from commit 8f565bdd14eec5611cc041dba4650e42ccdf71d9) Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
-rw-r--r--drivers/gpu/drm/xe/xe_vm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index ccb09ef4ec9e..cdd1dc540a59 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3369,8 +3369,10 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
op == DRM_XE_VM_BIND_OP_PREFETCH) ||
XE_IOCTL_DBG(xe, prefetch_region &&
op != DRM_XE_VM_BIND_OP_PREFETCH) ||
- XE_IOCTL_DBG(xe, (prefetch_region != DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC &&
- !(BIT(prefetch_region) & xe->info.mem_region_mask))) ||
+ XE_IOCTL_DBG(xe, (prefetch_region != DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC &&
+ /* Guard against undefined shift in BIT(prefetch_region) */
+ (prefetch_region >= (sizeof(xe->info.mem_region_mask) * 8) ||
+ !(BIT(prefetch_region) & xe->info.mem_region_mask)))) ||
XE_IOCTL_DBG(xe, obj &&
op == DRM_XE_VM_BIND_OP_UNMAP) ||
XE_IOCTL_DBG(xe, (flags & DRM_XE_VM_BIND_FLAG_MADVISE_AUTORESET) &&