2020-06-30 06:54:38

by Carl Huang

Subject: [PATCH v2] net: qrtr: free flow in __qrtr_node_release

The flow is allocated in qrtr_tx_wait, but not freed when qrtr node
is released. (*slot) becomes NULL after radix_tree_iter_delete is
called in __qrtr_node_release. The fix is to save (*slot) to a
vairable and then free it.

This memory leak is catched when kmemleak is enabled in kernel,
the report looks like below:

unreferenced object 0xffffa0de69e08420 (size 32):
comm "kworker/u16:3", pid 176, jiffies 4294918275 (age 82858.876s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 28 84 e0 69 de a0 ff ff ........(..i....
28 84 e0 69 de a0 ff ff 03 00 00 00 00 00 00 00 (..i............
backtrace:
[<00000000e252af0a>] qrtr_node_enqueue+0x38e/0x400 [qrtr]
[<000000009cea437f>] qrtr_sendmsg+0x1e0/0x2a0 [qrtr]
[<000000008bddbba4>] sock_sendmsg+0x5b/0x60
[<0000000003beb43a>] qmi_send_message.isra.3+0xbe/0x110 [qmi_helpers]
[<000000009c9ae7de>] qmi_send_request+0x1c/0x20 [qmi_helpers]

Signed-off-by: Carl Huang <[email protected]>
---
net/qrtr/qrtr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 2d8d613..0598813 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -166,6 +166,7 @@ static void __qrtr_node_release(struct kref *kref)
{
struct qrtr_node *node = container_of(kref, struct qrtr_node, ref);
struct radix_tree_iter iter;
+ struct qrtr_tx_flow *flow;
unsigned long flags;
void __rcu **slot;

@@ -181,8 +182,9 @@ static void __qrtr_node_release(struct kref *kref)

/* Free tx flow counters */
radix_tree_for_each_slot(slot, &node->qrtr_tx_flow, &iter, 0) {
+ flow = *slot;
radix_tree_iter_delete(&node->qrtr_tx_flow, &iter, slot);
- kfree(*slot);
+ kfree(flow);
}
kfree(node);
}
--
2.7.4

2020-06-30 23:29:42

by David Miller

Subject: Re: [PATCH v2] net: qrtr: free flow in __qrtr_node_release

From: Carl Huang <[email protected]>
Date: Tue, 30 Jun 2020 14:52:51 +0800

> The flow is allocated in qrtr_tx_wait, but not freed when qrtr node
> is released. (*slot) becomes NULL after radix_tree_iter_delete is
> called in __qrtr_node_release. The fix is to save (*slot) to a
> vairable and then free it.
>
> This memory leak is catched when kmemleak is enabled in kernel,
> the report looks like below:
>
> unreferenced object 0xffffa0de69e08420 (size 32):
> comm "kworker/u16:3", pid 176, jiffies 4294918275 (age 82858.876s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 28 84 e0 69 de a0 ff ff ........(..i....
> 28 84 e0 69 de a0 ff ff 03 00 00 00 00 00 00 00 (..i............
> backtrace:
> [<00000000e252af0a>] qrtr_node_enqueue+0x38e/0x400 [qrtr]
> [<000000009cea437f>] qrtr_sendmsg+0x1e0/0x2a0 [qrtr]
> [<000000008bddbba4>] sock_sendmsg+0x5b/0x60
> [<0000000003beb43a>] qmi_send_message.isra.3+0xbe/0x110 [qmi_helpers]
> [<000000009c9ae7de>] qmi_send_request+0x1c/0x20 [qmi_helpers]
>
> Signed-off-by: Carl Huang <[email protected]>

Applied and queued up for -stable, thanks.