4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit 6330d5534786d5315d56d558aa6d20740f97d80a upstream.
When built as a module and running with update_ms >= 0, pstore will Oops
during module unload since the work timer is still running. This makes sure
the worker is stopped before unloading.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/pstore/platform.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -704,6 +704,7 @@ int pstore_register(struct pstore_info *
if (psi->flags & PSTORE_FLAGS_PMSG)
pstore_register_pmsg();
+ /* Start watching for new records, if desired. */
if (pstore_update_ms >= 0) {
pstore_timer.expires = jiffies +
msecs_to_jiffies(pstore_update_ms);
@@ -726,6 +727,11 @@ EXPORT_SYMBOL_GPL(pstore_register);
void pstore_unregister(struct pstore_info *psi)
{
+ /* Stop timer and make sure all work has finished. */
+ pstore_update_ms = -1;
+ del_timer_sync(&pstore_timer);
+ flush_work(&pstore_work);
+
if (psi->flags & PSTORE_FLAGS_PMSG)
pstore_unregister_pmsg();
if (psi->flags & PSTORE_FLAGS_FTRACE)
@@ -825,7 +831,9 @@ static void pstore_timefunc(unsigned lon
schedule_work(&pstore_work);
}
- mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
+ if (pstore_update_ms >= 0)
+ mod_timer(&pstore_timer,
+ jiffies + msecs_to_jiffies(pstore_update_ms));
}
module_param(backend, charp, 0444);