6.11-stable review patch. If anyone has any objections, please let me know.
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From: Jiawei Ye jiawei.ye@foxmail.com
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@vger.kernel.org Signed-off-by: Jiawei Ye jiawei.ye@foxmail.com Acked-by: Miquel Raynal miquel.raynal@bootlin.com Reviewed-by: Przemek Kitszel przemyslaw.kitszel@intel.com Link: https://lore.kernel.org/tencent_3B2F4F2B4DA30FAE2F51A9634A16B3AD4908@qq.com Signed-off-by: Stefan Schmidt stefan@datenfreihafen.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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,