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authorZheng Wang <zyytlz.wz@163.com>2023-03-12 19:08:37 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-22 15:28:05 +0300
commitb0c202a8dc63008205a5d546559736507a9aae66 (patch)
treef8dbdc77edb70b53063937525877466a3ec18140 /drivers
parent668de67d41107c14999a06ebe5af5699087bbf99 (diff)
downloadlinux-b0c202a8dc63008205a5d546559736507a9aae66.tar.xz
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@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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/nfc/st-nci/ndlc.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/nfc/st-nci/ndlc.c b/drivers/nfc/st-nci/ndlc.c
index 5d74c674368a..8ccf5a86ad1b 100644
--- a/drivers/nfc/st-nci/ndlc.c
+++ b/drivers/nfc/st-nci/ndlc.c
@@ -286,13 +286,15 @@ 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);