diff options
| author | Zheng Wang <zyytlz.wz@163.com> | 2023-03-13 00:08:37 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-03-15 00:28:23 -0700 |
| commit | 5000fe6c27827a61d8250a7e4a1d26c3298ef4f6 (patch) | |
| tree | 8a8fa841617b149e8523b1f78caf4bbe1f1552d0 /drivers/nfc | |
| parent | cf18d55e535b34fd4845e87e31e1c5609db6d0a3 (diff) | |
nfc: st-nci: Fix use after free bug in ndlc_remove due to race condition
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@163.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230312160837.2040857-1-zyytlz.wz@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/nfc')
| -rw-r--r-- | drivers/nfc/st-nci/ndlc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/nfc/st-nci/ndlc.c b/drivers/nfc/st-nci/ndlc.c index 755460a73c0d..d2aa9f766738 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); |