lkml.org 
[lkml]   [2020]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.9 117/147] drivers: watchdog: rdc321x_wdt: Fix race condition bugs
    Date
    From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

    [ Upstream commit 4b2e7f99cdd314263c9d172bc17193b8b6bba463 ]

    In rdc321x_wdt_probe(), rdc321x_wdt_device.queue is initialized
    after misc_register(), hence if ioctl is called before its
    initialization which can call rdc321x_wdt_start() function,
    it will see an uninitialized value of rdc321x_wdt_device.queue,
    hence initialize it before misc_register().
    Also, rdc321x_wdt_device.default_ticks is accessed in reset()
    function called from write callback, thus initialize it before
    misc_register().

    Found by Linux Driver Verification project (linuxtesting.org).

    Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
    Reviewed-by: Guenter Roeck <linux@roeck-us.net>
    Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
    Link: https://lore.kernel.org/r/20200807112902.28764-1-madhuparnabhowmik10@gmail.com
    Signed-off-by: Guenter Roeck <linux@roeck-us.net>
    Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/watchdog/rdc321x_wdt.c | 5 ++---
    1 file changed, 2 insertions(+), 3 deletions(-)

    diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c
    index 57187efeb86f1..f0c94ea51c3e4 100644
    --- a/drivers/watchdog/rdc321x_wdt.c
    +++ b/drivers/watchdog/rdc321x_wdt.c
    @@ -231,6 +231,8 @@ static int rdc321x_wdt_probe(struct platform_device *pdev)

    rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
    rdc321x_wdt_device.base_reg = r->start;
    + rdc321x_wdt_device.queue = 0;
    + rdc321x_wdt_device.default_ticks = ticks;

    err = misc_register(&rdc321x_wdt_misc);
    if (err < 0) {
    @@ -245,14 +247,11 @@ static int rdc321x_wdt_probe(struct platform_device *pdev)
    rdc321x_wdt_device.base_reg, RDC_WDT_RST);

    init_completion(&rdc321x_wdt_device.stop);
    - rdc321x_wdt_device.queue = 0;

    clear_bit(0, &rdc321x_wdt_device.inuse);

    timer_setup(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);

    - rdc321x_wdt_device.default_ticks = ticks;
    -
    dev_info(&pdev->dev, "watchdog init success\n");

    return 0;
    --
    2.25.1
    \
     
     \ /
      Last update: 2020-10-27 01:33    [W:4.141 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site