DEBIAN-CVE-2026-23390

In the Linux kernel, the following vulnerability has been resolved:  tracing/dma: Cap dmamapsg tracepoint arrays to prevent buffer overflow  The dmamapsg tracepoint can trigger a perf buffer overflow when tracing large scatter-gather lists. With devices like virtio-gpu creating large DRM buffers, nents can exceed 1000 entries, resulting in:    physaddrs: 1000 * 8 bytes = 8,000 bytes   dmaaddrs:  1000  8 bytes = 8,000 bytes   lengths:    1000  4 bytes = 4,000 bytes   Total: ~20,000 bytes  This exceeds PERFMAXTRACESIZE (8192 bytes), causing:    WARNING: CPU: 0 PID: 5497 at kernel/trace/traceeventperf.c:405   perf buffer not large enough, wanted 24620, have 8192  Cap all three dynamic arrays at 128 entries using min() in the array size calculation. This ensures arrays are only as large as needed (up to the cap), avoiding unnecessary memory allocation for small operations while preventing overflow for large ones.  The tracepoint now records the full nents/ents counts and a truncated flag so users can see when data has been capped.  Changes in v2: - Use min(nents, DMATRACEMAXENTRIES) for dynamic array sizing   instead of fixed DMATRACEMAX_ENTRIES allocation (feedback from   Steven Rostedt) - This allocates only what's needed up to the cap, avoiding waste   for small operations  Reviwed-by: Sean Anderson sean.anderson@linux.dev