psz_init_zones is not supposed to return NULL. It returns an errno,
and its caller always checks for an errno to look for a problem.
If the caller receives a NULL as a return, this code will go further
without any errors:
cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off,
info->total_size - off_size,
info->kmsg_size, &cxt->kmsg_max_cnt);
if (IS_ERR(cxt->kpszs)) {
err = PTR_ERR(cxt->kpszs);
cxt->kpszs = NULL;
goto free_out;
}
Later, when dereferencing kpszs, a panic would occur.
Thus, to avoid this possible crash, it's better to avoid returning NULL
in psz_init_zones, and just return -EINVAL if the parameters received
are wrong (in this case, a zero size request).
Fixes: d26c3321fe18 ("pstore/zone: Introduce common layer to manage storage
zones")
Signed-off-by: Eugen Hristev <[email protected]>
---
fs/pstore/zone.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c
index 5fa2fa2e7aa7..dbafc72a2f68 100644
--- a/fs/pstore/zone.c
+++ b/fs/pstore/zone.c
@@ -1204,7 +1204,7 @@ static struct pstore_zone **psz_init_zones(enum
pstore_type_id type,
*cnt = 0;
if (!total_size || !record_size)
- return NULL;
+ return ERR_PTR(-EINVAL);
if (*off + total_size > info->total_size) {
pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n",
--
2.43.0
