linux/drivers/md/dm-stats.c
Mikulas Patocka cc87e26d9c dm-stats: fix a crash if allocation of per-cpu data fails
If "dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu))" fails, the code
jumps to the "out" label and calls dm_stat_free. dm_stat_free does
"for_each_possible_cpu(cpu) { dm_kvfree(s->stat_percpu[cpu][0].histogram,
s->histogram_alloc_size);", which crashes with NULL pointer dereference
if s->stat_percpu[cpu] is NULL.

This commit fixes the bug by testing s->stat_percpu[cpu] for NULL before
using it.

Reported-by: Junzhe Yu <junzheyu1@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: fd2ed4d252 ("dm: add statistics support")
Cc: stable@vger.kernel.org
2026-08-04 10:20:10 +02:00

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30 KiB