imrcpan/erofs-linux
1
0 Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git synced 2026-10-28 12:53:14 +01:00
Code Issues Packages Projects Releases Wiki Activity

dm-stats: fix a crash if allocation of per-cpu data fails

Browse Source 
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 <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
Fixes: fd2ed4d252 ("dm: add statistics support")
Cc: [email protected]
This commit is contained in:
Mikulas Patocka committed 2026-08-04 10:20:10 +02:00
1 parent 4538a287bd
commit cc87e26d9c
1 file changed
+4 -2
Download Patch File Download Diff File Expand all files Collapse all files
drivers/md/dm-stats.c
+4 -2
View File
@@ -178,8 +178,10 @@ static void dm_stat_free(struct rcu_head *head)
kfree(s->program_id);
kfree(s->aux_data);
for_each_possible_cpu(cpu) {
dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
if (s->stat_percpu[cpu]) {
dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
}
}
dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size);
dm_kvfree(s, s->shared_alloc_size);