[PATCH 5.14 051/169] ptp: Fix possible memory leak in ptp_clock_register()

Greg Kroah-Hartman
2021-10-25T19:50:16Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 4225fea1cb28370086e17e82c0f69bec2779dca0 ]

I got memory leak as follows when doing fault injection test:

unreferenced object 0xffff88800906c618 (size 8):
comm "i2c-idt82p33931", pid 4421, jiffies 4294948083 (age 13.188s)
hex dump (first 8 bytes):
70 74 70 30 00 00 00 00 ptp0....
backtrace:
[<00000000312ed458>] __kmalloc_track_caller+0x19f/0x3a0
[<0000000079f6e2ff>] kvasprintf+0xb5/0x150
[<0000000026aae54f>] kvasprintf_const+0x60/0x190
[<00000000f323a5f7>] kobject_set_name_vargs+0x56/0x150
[<000000004e35abdd>] dev_set_name+0xc0/0x100
[<00000000f20cfe25>] ptp_clock_register+0x9f4/0xd30 [ptp]
[<000000008bb9f0de>] idt82p33_probe.cold+0x8b6/0x1561 [ptp_idt82p33]

When posix_clock_register() returns an error, the name allocated
in dev_set_name() will be leaked, the put_device() should be used
to give up the device reference, then the name will be freed in
kobject_cleanup() and other memory will be freed in ptp_clock_release().

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: a33121e5487b ("ptp: fix the race between the release of ptp_clock and cdev")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ptp/ptp_clock.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 4dfc52e06704..7fd02aabd79a 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -283,15 +283,22 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
/* Create a posix clock and link it to the device. */
err = posix_clock_register(&ptp->clock, &ptp->dev);
if (err) {
+ if (ptp->pps_source)
+ pps_unregister_source(ptp->pps_source);
+
+ kfree(ptp->vclock_index);
+
+ if (ptp->kworker)
+ kthread_destroy_worker(ptp->kworker);
+
+ put_device(&ptp->dev);
+
pr_err("failed to create posix clock\n");
- goto no_clock;
+ return ERR_PTR(err);
}

return ptp;

-no_clock:
- if (ptp->pps_source)
- pps_unregister_source(ptp->pps_source);
no_pps:
ptp_cleanup_pin_groups(ptp);
no_pin_groups:
--
2.33.0