CVE-2025-40225

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/panthor: Fix kernel panic on partial unmap of a GPU VA region<br /> <br /> This commit address a kernel panic issue that can happen if Userspace<br /> tries to partially unmap a GPU virtual region (aka drm_gpuva).<br /> The VM_BIND interface allows partial unmapping of a BO.<br /> <br /> Panthor driver pre-allocates memory for the new drm_gpuva structures<br /> that would be needed for the map/unmap operation, done using drm_gpuvm<br /> layer. It expected that only one new drm_gpuva would be needed on umap<br /> but a partial unmap can require 2 new drm_gpuva and that&amp;#39;s why it<br /> ended up doing a NULL pointer dereference causing a kernel panic.<br /> <br /> Following dump was seen when partial unmap was exercised.<br /> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000078<br /> Mem abort info:<br /> ESR = 0x0000000096000046<br /> EC = 0x25: DABT (current EL), IL = 32 bits<br /> SET = 0, FnV = 0<br /> EA = 0, S1PTW = 0<br /> FSC = 0x06: level 2 translation fault<br /> Data abort info:<br /> ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000<br /> CM = 0, WnR = 1, TnD = 0, TagAccess = 0<br /> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0<br /> user pgtable: 4k pages, 48-bit VAs, pgdp=000000088a863000<br /> [000000000000078] pgd=080000088a842003, p4d=080000088a842003, pud=0800000884bf5003, pmd=0000000000000000<br /> Internal error: Oops: 0000000096000046 [#1] PREEMPT SMP<br /> <br /> pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> pc : panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor]<br /> lr : panthor_gpuva_sm_step_remap+0x6c/0x330 [panthor]<br /> sp : ffff800085d43970<br /> x29: ffff800085d43970 x28: ffff00080363e440 x27: ffff0008090c6000<br /> x26: 0000000000000030 x25: ffff800085d439f8 x24: ffff00080d402000<br /> x23: ffff800085d43b60 x22: ffff800085d439e0 x21: ffff00080abdb180<br /> x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000010<br /> x17: 6e656c202c303030 x16: 3666666666646466 x15: 393d61766f69202c<br /> x14: 312d3d7361203a70 x13: 303030323d6e656c x12: ffff80008324bf58<br /> x11: 0000000000000003 x10: 0000000000000002 x9 : ffff8000801a6a9c<br /> x8 : ffff00080360b300 x7 : 0000000000000000 x6 : 000000088aa35fc7<br /> x5 : fff1000080000000 x4 : ffff8000842ddd30 x3 : 0000000000000001<br /> x2 : 0000000100000000 x1 : 0000000000000001 x0 : 0000000000000078<br /> Call trace:<br /> panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor]<br /> op_remap_cb.isra.22+0x50/0x80<br /> __drm_gpuvm_sm_unmap+0x10c/0x1c8<br /> drm_gpuvm_sm_unmap+0x40/0x60<br /> panthor_vm_exec_op+0xb4/0x3d0 [panthor]<br /> panthor_vm_bind_exec_sync_op+0x154/0x278 [panthor]<br /> panthor_ioctl_vm_bind+0x160/0x4a0 [panthor]<br /> drm_ioctl_kernel+0xbc/0x138<br /> drm_ioctl+0x240/0x500<br /> __arm64_sys_ioctl+0xb0/0xf8<br /> invoke_syscall+0x4c/0x110<br /> el0_svc_common.constprop.1+0x98/0xf8<br /> do_el0_svc+0x24/0x38<br /> el0_svc+0x40/0xf8<br /> el0t_64_sync_handler+0xa0/0xc8<br /> el0t_64_sync+0x174/0x178