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| author | Wang Wensheng <wangwensheng4@huawei.com> | 2020-11-09 13:05:12 +0000 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2020-12-13 16:17:43 +0100 |
| commit | 6f733cb2e7db38f8141b14740bcde577844a03b7 (patch) | |
| tree | 00e050f54e25dc45ff794f891e3e9cdabbb18305 /drivers/watchdog/iTCO_wdt.c | |
| parent | 24f98562bb5b1cd6184c583fb53a6068992bec4b (diff) | |
watchdog: Fix potential dereferencing of null pointer
A reboot notifier, which stops the WDT by calling the stop hook without
any check, would be registered when we set WDOG_STOP_ON_REBOOT flag.
Howerer we allow the WDT driver to omit the stop hook since commit
"d0684c8a93549" ("watchdog: Make stop function optional") and provide
a module parameter for user that controls the WDOG_STOP_ON_REBOOT flag
in commit 9232c80659e94 ("watchdog: Add stop_on_reboot parameter to
control reboot policy"). Together that commits make user potential to
insert a watchdog driver that don't provide a stop hook but with the
stop_on_reboot parameter set, then dereferencing of null pointer occurs
on system reboot.
Check the stop hook before registering the reboot notifier to fix the
issue.
Fixes: d0684c8a9354 ("watchdog: Make stop function optional")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201109130512.28121-1-wangwensheng4@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/iTCO_wdt.c')
0 files changed, 0 insertions, 0 deletions