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authorZou Wei <zou_wei@huawei.com>2021-05-12 14:57:56 +0800
committerWim Van Sebroeck <wim@linux-watchdog.org>2021-06-21 08:49:03 +0200
commitd0212f095ab56672f6f36aabc605bda205e1e0bf (patch)
treeb8e7ed858241af9a664bf25a72751ce7f7bbaf4e /drivers/watchdog
parent90b7c141132244e8e49a34a4c1e445cce33e07f4 (diff)
downloadlinux-d0212f095ab56672f6f36aabc605bda205e1e0bf.tar.bz2
watchdog: Fix possible use-after-free by calling del_timer_sync()
This driver's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Link: https://lore.kernel.org/r/1620802676-19701-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/lpc18xx_wdt.c2
-rw-r--r--drivers/watchdog/w83877f_wdt.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/watchdog/lpc18xx_wdt.c b/drivers/watchdog/lpc18xx_wdt.c
index 78cf11c94941..60b6d74f267d 100644
--- a/drivers/watchdog/lpc18xx_wdt.c
+++ b/drivers/watchdog/lpc18xx_wdt.c
@@ -292,7 +292,7 @@ static int lpc18xx_wdt_remove(struct platform_device *pdev)
struct lpc18xx_wdt_dev *lpc18xx_wdt = platform_get_drvdata(pdev);
dev_warn(&pdev->dev, "I quit now, hardware will probably reboot!\n");
- del_timer(&lpc18xx_wdt->timer);
+ del_timer_sync(&lpc18xx_wdt->timer);
return 0;
}
diff --git a/drivers/watchdog/w83877f_wdt.c b/drivers/watchdog/w83877f_wdt.c
index 5772cc5d3780..f2650863fd02 100644
--- a/drivers/watchdog/w83877f_wdt.c
+++ b/drivers/watchdog/w83877f_wdt.c
@@ -166,7 +166,7 @@ static void wdt_startup(void)
static void wdt_turnoff(void)
{
/* Stop the timer */
- del_timer(&timer);
+ del_timer_sync(&timer);
wdt_change(WDT_DISABLE);