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[4.19,233/421] atm: iphase: fix possible use-after-free in ia_module_exit()

Message ID 20210719144954.494139511@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH July 19, 2021, 2:50 p.m. UTC 
From: Zou Wei <zou_wei@huawei.com>

[ Upstream commit 1c72e6ab66b9598cac741ed397438a52065a8f1f ]

This module'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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/atm/iphase.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/atm/iphase.c b/drivers/atm/iphase.c
index 008905d4152a..827c6d5e6177 100644
--- a/drivers/atm/iphase.c
+++ b/drivers/atm/iphase.c
@@ -3301,7 +3301,7 @@  static void __exit ia_module_exit(void)
 {
 	pci_unregister_driver(&ia_driver);
 
-        del_timer(&ia_timer);
+	del_timer_sync(&ia_timer);
 }
 
 module_init(ia_module_init);