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Shuicheng Lin 4a6f3dff46 drm/xe: Prevent BIT() overflow when handling invalid prefetch region
[ Upstream commit d52dea485c ]

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: dd08ebf6c3 ("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>
(cherry picked from commit d52dea485c)
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01 11:46:04 +01:00
2025-12-01 11:46:04 +01:00
2025-12-01 11:45:37 +01:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -07:00
2025-11-24 10:37:52 +01:00
2024-03-18 03:36:32 -06:00

Linux kernel
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