[PATCH 5.10] netdevsim: Fix memory leak of nsim_dev->fa_cookie

[PATCH 5.10] netdevsim: Fix memory leak of nsim_dev->fa_cookie

[Mikhail Dmitrichenko]

From: Wang Yufen <wangyufen@huawei.com>

commit 064bc7312bd09a48798418663090be0c776183db upstream.

kmemleak reports this issue:

unreferenced object 0xffff8881bac872d0 (size 8):
  comm "sh", pid 58603, jiffies 4481524462 (age 68.065s)
  hex dump (first 8 bytes):
    04 00 00 00 de ad be ef                          ........
  backtrace:
    [<00000000c80b8577>] __kmalloc+0x49/0x150
    [<000000005292b8c6>] nsim_dev_trap_fa_cookie_write+0xc1/0x210 [netdevsim]
    [<0000000093d78e77>] full_proxy_write+0xf3/0x180
    [<000000005a662c16>] vfs_write+0x1c5/0xaf0
    [<000000007aabf84a>] ksys_write+0xed/0x1c0
    [<000000005f1d2e47>] do_syscall_64+0x3b/0x90
    [<000000006001c6ec>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

The issue occurs in the following scenarios:

nsim_dev_trap_fa_cookie_write()
  kmalloc() fa_cookie
  nsim_dev->fa_cookie = fa_cookie
..
nsim_drv_remove()

The fa_cookie allocked in nsim_dev_trap_fa_cookie_write() is not freed. To
fix, add kfree(nsim_dev->fa_cookie) to nsim_drv_remove().

Fixes: d3cbb907ae57 ("netdevsim: add ACL trap reporting cookie as a metadata")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Link: https://lore.kernel.org/r/1668504625-14698-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ The context change is due to the commit 5e388f3dc38c
("netdevsim: move vfconfig to nsim_dev") in v5.16
which is irrelevant to the logic of this patch. ]
Signed-off-by: Mikhail Dmitrichenko <mdmitrichenko@astralinux.ru>
---
Backport fix for CVE-2022-49803
 drivers/net/netdevsim/dev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index c8834ea84732..a106365ce485 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -1173,6 +1173,7 @@ void nsim_dev_remove(struct nsim_bus_dev *nsim_bus_dev)
 				  ARRAY_SIZE(nsim_devlink_params));
 	devlink_unregister(devlink);
 	devlink_resources_unregister(devlink, NULL);
+	kfree(nsim_dev->fa_cookie);
 	devlink_free(devlink);
 }
 
-- 
2.47.3

Re: [PATCH 5.10] netdevsim: Fix memory leak of nsim_dev->fa_cookie

[Sasha Levin]

> [PATCH 5.10] netdevsim: Fix memory leak of nsim_dev->fa_cookie

Queued for 5.10, thanks.

-- 
Thanks,
Sasha