[PATCH 6.1 435/473] dma-mapping: benchmark: handle NUMA_NO_NODE correctly

Greg Kroah-Hartman
2024-06-06T14:19:05Z

From: Fedor Pchelkin <pchelkin@ispras.ru>

[ Upstream commit e64746e74f717961250a155e14c156616fcd981f ]

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).

Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/dma/map_benchmark.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
index 11ad1c43833d1..af661734e8f90 100644
--- a/kernel/dma/map_benchmark.c
+++ b/kernel/dma/map_benchmark.c
@@ -101,7 +101,6 @@ static int do_map_benchmark(struct map_benchmark_data *map)
struct task_struct **tsk;
int threads = map->bparam.threads;
int node = map->bparam.node;
- const cpumask_t *cpu_mask = cpumask_of_node(node);
u64 loops;
int ret = 0;
int i;
@@ -122,7 +121,7 @@ static int do_map_benchmark(struct map_benchmark_data *map)
}

if (node != NUMA_NO_NODE)
- kthread_bind_mask(tsk[i], cpu_mask);
+ kthread_bind_mask(tsk[i], cpumask_of_node(node));
}

/* clear the old value in the previous benchmark */
--
2.43.0