6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiawei Ye <jiawei.ye@xxxxxxxxxxx>
commit bff1709b3980bd7f80be6786f64cc9a9ee9e56da upstream.
In the `mac802154_scan_worker` function, the `scan_req->type` field was
accessed after the RCU read-side critical section was unlocked. According
to RCU usage rules, this is illegal and can lead to unpredictable
behavior, such as accessing memory that has been updated or causing
use-after-free issues.
This possible bug was identified using a static analysis tool developed
by myself, specifically designed to detect RCU-related issues.
To address this, the `scan_req->type` value is now stored in a local
variable `scan_req_type` while still within the RCU read-side critical
section. The `scan_req_type` is then used after the RCU lock is released,
ensuring that the type value is safely accessed without violating RCU
rules.
Fixes: e2c3e6f53a7a ("mac802154: Handle active scanning")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiawei Ye <jiawei.ye@xxxxxxxxxxx>
Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>
Link: https://lore.kernel.org/tencent_3B2F4F2B4DA30FAE2F51A9634A16B3AD4908@xxxxxx
Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mac802154/scan.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -176,6 +176,7 @@ void mac802154_scan_worker(struct work_s
struct ieee802154_local *local =
container_of(work, struct ieee802154_local, scan_work.work);
struct cfg802154_scan_request *scan_req;
+ enum nl802154_scan_types scan_req_type;
struct ieee802154_sub_if_data *sdata;
unsigned int scan_duration = 0;
struct wpan_phy *wpan_phy;
@@ -209,6 +210,7 @@ void mac802154_scan_worker(struct work_s
}
wpan_phy = scan_req->wpan_phy;
+ scan_req_type = scan_req->type;
scan_req_duration = scan_req->duration;
/* Look for the next valid chan */
@@ -246,7 +248,7 @@ void mac802154_scan_worker(struct work_s
goto end_scan;
}
- if (scan_req->type == NL802154_SCAN_ACTIVE) {
+ if (scan_req_type == NL802154_SCAN_ACTIVE) {
ret = mac802154_transmit_beacon_req(local, sdata);
if (ret)
dev_err(&sdata->dev->dev,
