lkml.org 
[lkml]   [2022]   [Aug]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.19 243/287] atm: idt77252: fix use-after-free bugs caused by tst_timer
    Date
    From: Duoming Zhou <duoming@zju.edu.cn>

    commit 3f4093e2bf4673f218c0bf17d8362337c400e77b upstream.

    There are use-after-free bugs caused by tst_timer. The root cause
    is that there are no functions to stop tst_timer in idt77252_exit().
    One of the possible race conditions is shown below:

    (thread 1) | (thread 2)
    | idt77252_init_one
    | init_card
    | fill_tst
    | mod_timer(&card->tst_timer, ...)
    idt77252_exit | (wait a time)
    | tst_timer
    |
    | ...
    kfree(card) // FREE |
    | card->soft_tst[e] // USE

    The idt77252_dev is deallocated in idt77252_exit() and used in
    timer handler.

    This patch adds del_timer_sync() in idt77252_exit() in order that
    the timer handler could be stopped before the idt77252_dev is
    deallocated.

    Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
    Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
    Link: https://lore.kernel.org/r/20220805070008.18007-1-duoming@zju.edu.cn
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/atm/idt77252.c | 1 +
    1 file changed, 1 insertion(+)

    --- a/drivers/atm/idt77252.c
    +++ b/drivers/atm/idt77252.c
    @@ -3767,6 +3767,7 @@ static void __exit idt77252_exit(void)
    card = idt77252_chain;
    dev = card->atmdev;
    idt77252_chain = card->next;
    + del_timer_sync(&card->tst_timer);

    if (dev->phy->stop)
    dev->phy->stop(dev);

    \
     
     \ /
      Last update: 2022-08-23 13:06    [W:2.744 / U:0.328 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site