This is a note to let you know that I've just added the patch titled
nfc: st-nci: Fix use after free bug in ndlc_remove due to race condition
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfc-st-nci-fix-use-after-free-bug-in-ndlc_remove-due.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit adea77778829e04bcbd3aa3dd73ff30adb875792
Author: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Mon Mar 13 00:08:37 2023 +0800
nfc: st-nci: Fix use after free bug in ndlc_remove due to race condition
[ Upstream commit 5000fe6c27827a61d8250a7e4a1d26c3298ef4f6 ]
This bug influences both st_nci_i2c_remove and st_nci_spi_remove.
Take st_nci_i2c_remove as an example.
In st_nci_i2c_probe, it called ndlc_probe and bound &ndlc->sm_work
with llt_ndlc_sm_work.
When it calls ndlc_recv or timeout handler, it will finally call
schedule_work to start the work.
When we call st_nci_i2c_remove to remove the driver, there
may be a sequence as follows:
Fix it by finishing the work before cleanup in ndlc_remove
CPU0 CPU1
|llt_ndlc_sm_work
st_nci_i2c_remove |
ndlc_remove |
st_nci_remove |
nci_free_device|
kfree(ndev) |
//free ndlc->ndev |
|llt_ndlc_rcv_queue
|nci_recv_frame
|//use ndlc->ndev
Fixes: 35630df68d60 ("NFC: st21nfcb: Add driver for STMicroelectronics ST21NFCB NFC chip")
Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230312160837.2040857-1-zyytlz.wz@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/nfc/st-nci/ndlc.c b/drivers/nfc/st-nci/ndlc.c
index 755460a73c0dc..d2aa9f766738e 100644
--- a/drivers/nfc/st-nci/ndlc.c
+++ b/drivers/nfc/st-nci/ndlc.c
@@ -282,13 +282,15 @@ EXPORT_SYMBOL(ndlc_probe);
void ndlc_remove(struct llt_ndlc *ndlc)
{
- st_nci_remove(ndlc->ndev);
-
/* cancel timers */
del_timer_sync(&ndlc->t1_timer);
del_timer_sync(&ndlc->t2_timer);
ndlc->t2_active = false;
ndlc->t1_active = false;
+ /* cancel work */
+ cancel_work_sync(&ndlc->sm_work);
+
+ st_nci_remove(ndlc->ndev);
skb_queue_purge(&ndlc->rcv_q);
skb_queue_purge(&ndlc->send_q);
