From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: kys@microsoft.com, haiyangz@microsoft.com,
sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com,
gregkh@linuxfoundation.org
Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org,
Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: [PATCH 1/2] uio_hv_generic: Fix a memory leak in error handling paths
Date: Sun, 9 May 2021 09:13:03 +0200 [thread overview]
Message-ID: <4fdaff557deef6f0475d02ba7922ddbaa1ab08a6.1620544055.git.christophe.jaillet@wanadoo.fr> (raw)
If 'vmbus_establish_gpadl()' fails, the (recv|send)_gpadl will not be
updated and 'hv_uio_cleanup()' in the error handling path will not be
able to free the corresponding buffer.
In such a case, we need to free the buffer explicitly.
Fixes: cdfa835c6e5e ("uio_hv_generic: defer opening vmbus until first use")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Before commit cdfa835c6e5e, the 'vfree' were done unconditionally
in 'hv_uio_cleanup()'.
So, another way for fixing the potential leak is to modify
'hv_uio_cleanup()' and revert to the previous behavior.
I don't know the underlying reason for this change so I don't know which is
the best way to fix this error handling path. Unless there is a specific
reason, changing 'hv_uio_cleanup()' could be better because it would keep
the error handling path of the probe cleaner, IMHO.
---
drivers/uio/uio_hv_generic.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 0330ba99730e..eebc399f2cc7 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -296,8 +296,10 @@ hv_uio_probe(struct hv_device *dev,
ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
RECV_BUFFER_SIZE, &pdata->recv_gpadl);
- if (ret)
+ if (ret) {
+ vfree(pdata->recv_buf);
goto fail_close;
+ }
/* put Global Physical Address Label in name */
snprintf(pdata->recv_name, sizeof(pdata->recv_name),
@@ -316,8 +318,10 @@ hv_uio_probe(struct hv_device *dev,
ret = vmbus_establish_gpadl(channel, pdata->send_buf,
SEND_BUFFER_SIZE, &pdata->send_gpadl);
- if (ret)
+ if (ret) {
+ vfree(pdata->send_buf);
goto fail_close;
+ }
snprintf(pdata->send_name, sizeof(pdata->send_name),
"send:%u", pdata->send_gpadl);
--
2.30.2
next reply other threads:[~2021-05-09 7:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-09 7:13 Christophe JAILLET [this message]
2021-05-09 7:13 ` [PATCH 2/2] uio_hv_generic: Fix another memory leak in error handling paths Christophe JAILLET
2021-05-11 9:52 ` [PATCH 1/2] uio_hv_generic: Fix a " Wei Liu
2021-05-11 18:18 ` Christophe JAILLET
2021-05-15 16:09 ` Wei Liu
2021-05-18 20:46 ` Christophe JAILLET
2021-05-18 11:01 ` Wei Liu
2021-05-18 21:50 ` Long Li
2021-05-18 21:53 ` Wei Liu
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