CVE-2024-39277: Out-of-bounds Read

In the Linux kernel, the following vulnerability has been resolved:

dma-mapping: benchmark: handle NUMA_NO_NODE correctly

cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark() resulting in the following sanitizer report:

UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28 index -1 is out of range for type 'cpumask [64][1]' CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117) ubsan_epilogue (lib/ubsan.c:232) __ubsan_handle_out_of_bounds (lib/ubsan.c:429) cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline] do_map_benchmark (kernel/dma/map_benchmark.c:104) map_benchmark_ioctl (kernel/dma/map_benchmark.c:246) full_proxy_unlocked_ioctl (fs/debugfs/file.c:333) __x64_sys_ioctl (fs/ioctl.c:890) do_syscall_64 (arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Use cpumask_of_node() in place when binding a kernel thread to a cpuset of a particular node.

Note that the provided node id is checked inside map_benchmark_ioctl(). It's just a NUMA_NO_NODE case which is not handled properly later.

Found by Linux Verification Center (linuxtesting.org).