Threats Tagged 'ubuntu-pro-fips-20-04-lts'

Excessive Memory Use Buffering DTLS Records for a Future Epoch

Heap Buffer Overflow in CMS Key Unwrapping

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: bound DMA command body size against suffix pointer vmw_cmd_dma() locates the DMA suffix at (unsigned long) &cmd->body + header->size - sizeof(*suffix) without checking that header->size is large enough to contain both cmd->body and the suffix. An undersized header makes the suffix pointer underflow back into the previous command in the bounce buffer. The verifier later writes suffix->maximumOffset, clobbering verified fields of an already-relocated earlier command -- a TOCTOU on the device-visible command stream that lets one command rewrite another's GMR id, surface id, or other authenticated fields. Reject the command if the body is too small for the suffix to fit.

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: validate DRAW_PRIMITIVES header size before division vmw_cmd_draw() computes maxnum = (header->size - sizeof(cmd->body)) / sizeof(*decl); where header->size is u32 and is taken straight from the user-supplied command stream. When header->size is less than sizeof(cmd->body) the unsigned subtraction wraps to nearly 4 GiB, producing a huge maxnum. Any user-controlled cmd->body.numVertexDecls then passes the bound and the loop dereferences decl[i] far past the end of the kernel command bounce buffer, producing an out-of-bounds read of kernel memory. Reject undersized headers up front.

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: reject DX_BIND_QUERY without a DX context vmw_cmd_dx_bind_query() unconditionally dereferences sw_context->dx_ctx_node->ctx. Userspace can trigger a NULL pointer dereference from any render-node fd by submitting an execbuf with dx_context_handle == SVGA3D_INVALID_ID and a SVGA_3D_CMD_DX_BIND_QUERY opcode in the command stream: dx_ctx_node is left NULL and the kernel oopses on the assignment. The same NULL is then re-read in vmw_resources_reserve() via vmw_context_get_dx_query_mob(). All sibling DX handlers fail-close on a missing dx_ctx_node using VMW_GET_CTX_NODE(). Use the same pattern here, returning -EINVAL up front before any relocation state is published.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix QID bit leak in pqm_create_queue() When MES is enabled and amdgpu_amdkfd_alloc_kernel_mem() fails during the first queue creation for a process, pqm_create_queue() returns early via 'return retval' without going through the err_create_queue cleanup label. This means clear_bit(*qid, pqm->queue_slot_bitmap) is never called, leaving the reserved QID bit permanently set in queue_slot_bitmap. Over time this leaks QID slots, potentially exhausting all available queue slots. Fix this by replacing 'return retval' with 'goto err_allocate_pqn' so that clear_bit() is always called on the error path without touching the uninitialized pqn pointer. AILIKFD-813 (cherry picked from commit a107f74c38edbb80d6ab64dcaeeb292c14e9779f)

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix divide-by-zero in calculate_mcache_setting on zero viewport If a plane reaches calculate_mcache_setting with a zero-area viewport, calculate_mcache_setting exits early with num_mcaches == 0 and mvmpg_width/height == 0. This will cause a divide-by-zero panic and can also cause an underflow on num_mcaches. Fix this by changing calculate_mcache_setting to bool and adding guards after each calculate_mcache_row_bytes call. If num_mcaches or mvmpg_width/height is zero, return a false. Callers will propagate the failure as a rejected mode, which prevents the panic. (cherry picked from commit 29c0f7c655f47bcbd575ff75e58480df6ec3c9da)

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix pptable use-after-free amdgpu_dpm_get_pp_table() returns a pointer to a driver-owned power table after dropping adev->pm.mutex. The sysfs path then copies from that pointer. A concurrent pp_table write can replace and free the allocation during the copy, causing a use-after-free. Change the DPM interface to copy into caller-provided storage while the mutex is held. Keep the size-only query for attribute discovery without exposing the driver-owned pointer. (cherry picked from commit f6eed7acfd30099ef7baeb6ba45bb59daad80631)

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Zero the tile state data array before each BIN job The binner BO is a single 16MB buffer split into 512KB slots that are handed out to jobs at submission time and recycled as jobs complete, without ever being cleared. Each slot holds the job's Tile State Data Array (TSDA) at its start, followed by the tile allocation pool. While the tile allocation pool is only walked by the render thread through branches the binner generated during the current job, the TSDA is the PTB's own per-tile bookkeeping and is consumed by the hardware itself. Although the kernel sets the "Auto-initialise Tile State Data Array" flag in the tile binning mode configuration, the PTB demonstrably still acts on stale tile state left by the slot's previous user: the binner ends up creating invalid command streams with invalid primitive streams and branches, which can cause GPU hangs as observed in [1][2]. Zero the TSDA when the job's binning slot is configured. This clears 48 bytes per tile (~24KB for a 1080p frame) in the submission path, and guarantees the PTB never sees another job's tile state. The tile count is only checked for being non-zero today, so the 8-bit fields it comes from can describe a tile state array almost six times larger than the slot it has to live in. Bound it before the slot is handed out, since such size decides how much of the slot is left for the tile alloc pool.

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Supply the overflow slot size in BPOS, not the whole bin BO size vc4_overflow_mem_work() points BPOA at a 512KB slot inside the 16MB binner BO, but writes the size of the whole BO to BPOS. On every binner out-of-memory event the PTB is therefore authorized to write tile lists across all the other slots (which may hold the tile state, tile alloc and overflow memory of in-flight jobs) and, for any slot but the first, past the end of the binner BO into unrelated CMA memory. Since CMA pages are recycled into page cache and user allocations, this is arbitrary memory corruption by GPU DMA. In practice it shows up as GPU hangs with corrupted control list pointers, userspace heap corruption, a GPU that stays permanently wedged after the first hang, and occasional full system crashes, whenever a job overflows the initial binner slot. The bug dates back to the conversion from a dedicated overflow BO (where writing the full BO size was correct) to the slotted binner BO.