CVE-2025-68802

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/xe: Limit num_syncs to prevent oversized allocations<br /> <br /> The exec and vm_bind ioctl allow userspace to specify an arbitrary<br /> num_syncs value. Without bounds checking, a very large num_syncs<br /> can force an excessively large allocation, leading to kernel warnings<br /> from the page allocator as below.<br /> <br /> Introduce DRM_XE_MAX_SYNCS (set to 1024) and reject any request<br /> exceeding this limit.<br /> <br /> "<br /> ------------[ cut here ]------------<br /> WARNING: CPU: 0 PID: 1217 at mm/page_alloc.c:5124 __alloc_frozen_pages_noprof+0x2f8/0x2180 mm/page_alloc.c:5124<br /> ...<br /> Call Trace:<br /> <br /> alloc_pages_mpol+0xe4/0x330 mm/mempolicy.c:2416<br /> ___kmalloc_large_node+0xd8/0x110 mm/slub.c:4317<br /> __kmalloc_large_node_noprof+0x18/0xe0 mm/slub.c:4348<br /> __do_kmalloc_node mm/slub.c:4364 [inline]<br /> __kmalloc_noprof+0x3d4/0x4b0 mm/slub.c:4388<br /> kmalloc_noprof include/linux/slab.h:909 [inline]<br /> kmalloc_array_noprof include/linux/slab.h:948 [inline]<br /> xe_exec_ioctl+0xa47/0x1e70 drivers/gpu/drm/xe/xe_exec.c:158<br /> drm_ioctl_kernel+0x1f1/0x3e0 drivers/gpu/drm/drm_ioctl.c:797<br /> drm_ioctl+0x5e7/0xc50 drivers/gpu/drm/drm_ioctl.c:894<br /> xe_drm_ioctl+0x10b/0x170 drivers/gpu/drm/xe/xe_device.c:224<br /> vfs_ioctl fs/ioctl.c:51 [inline]<br /> __do_sys_ioctl fs/ioctl.c:598 [inline]<br /> __se_sys_ioctl fs/ioctl.c:584 [inline]<br /> __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584<br /> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]<br /> do_syscall_64+0xbb/0x380 arch/x86/entry/syscall_64.c:94<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> ...<br /> "<br /> <br /> v2: Add "Reported-by" and Cc stable kernels.<br /> v3: Change XE_MAX_SYNCS from 64 to 1024. (Matt &amp; Ashutosh)<br /> v4: s/XE_MAX_SYNCS/DRM_XE_MAX_SYNCS/ (Matt)<br /> v5: Do the check at the top of the exec func. (Matt)<br /> <br /> (cherry picked from commit b07bac9bd708ec468cd1b8a5fe70ae2ac9b0a11c)