Patch "nfc: st-nci: Fix use after free bug in ndlc_remove due to race condition" has been added to the 4.19-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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 4.19-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-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 61564ab9d39a52d1cba075b2b41b6385e8dc31aa
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 f26d938d240f0..12d73f9dbe9f3 100644
--- a/drivers/nfc/st-nci/ndlc.c
+++ b/drivers/nfc/st-nci/ndlc.c
@@ -297,13 +297,15 @@ 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);



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux