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perf mmap: Guard cpu__get_node() return in aio_bind()

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perf_mmap__aio_bind() passes the cpu__get_node() return value directly
to an unsigned long variable (node_index).  When cpu__get_node() returns
-1 for an unknown CPU, the implicit int-to-unsigned-long conversion
sign-extends it to ULONG_MAX.

This causes bitmap_zalloc(ULONG_MAX + 1) which wraps to
bitmap_zalloc(0), returning a zero-sized allocation.  The subsequent
__set_bit(ULONG_MAX, node_mask) then writes massively out of bounds.

Check the return value in a signed temporary before assigning to
node_index, and skip the NUMA binding when the node is unknown.

Fixes: c44a8b44ca ("perf record: Bind the AIO user space buffers to nodes")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2026-06-05 10:56:33 -03:00
parent 5949d339f5
commit f32dc302a0
1 changed files with 7 additions and 1 deletions
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8
tools/perf/util/mmap.c
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@ -104,9 +104,15 @@ static int perf_mmap__aio_bind(struct mmap *map, int idx, struct perf_cpu cpu, i
int err = 0;
if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) {
int node;
data = map->aio.data[idx];
mmap_len = mmap__mmap_len(map);
node_index = cpu__get_node(cpu);
node = cpu__get_node(cpu);
/* -1 sign-extends to ULONG_MAX, wrapping bitmap_zalloc(0) and OOB __set_bit */
if (node < 0)
return 0;
node_index = node;
node_mask = bitmap_zalloc(node_index + 1);
if (!node_mask) {
pr_err("Failed to allocate node mask for mbind: error %m\n");