In psz_init_zones, if the requested area has a total_size less than
record_size, kcalloc will be called with c == 0 and will return
ZERO_SIZE_PTR.
Further, this will lead to an oops.
With this patch, in this scenario, it will look like this :
[ 6.865545] pstore_zone: total size : 28672 Bytes
[ 6.865547] pstore_zone: kmsg size : 65536 Bytes
[ 6.865549] pstore_zone: pmsg size : 0 Bytes
[ 6.865551] pstore_zone: console size : 0 Bytes
[ 6.865553] pstore_zone: ftrace size : 0 Bytes
[ 6.872095] pstore_zone: zone dmesg total_size too small
[ 6.878234] pstore_zone: alloc zones failed
Signed-off-by: Eugen Hristev <eugen.hris...@linaro.org>
---
Changes in v2:
- reworked to check for c==0 instead of ZERO_SIZE_PTR as suggested by Kees Cook
fs/pstore/zone.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c
index 694db616663f..ceb5639a0629 100644
--- a/fs/pstore/zone.c
+++ b/fs/pstore/zone.c
@@ -1212,6 +1212,11 @@ static struct pstore_zone **psz_init_zones(enum
pstore_type_id type,
}
c = total_size / record_size;
+ if (unlikely(!c)) {
+ pr_err("zone %s total_size too small\n", name);
+ return ERR_PTR(-EINVAL);
+ }
+
zones = kcalloc(c, sizeof(*zones), GFP_KERNEL);
if (!zones) {
pr_err("allocate for zones %s failed\n", name);
--
2.43.0
