From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: John Fastabend <john.fastabend@gmail.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 164/205] bpf: skmsg, fix potential psock NULL pointer dereference
Date: Thu, 16 Jan 2020 11:42:19 -0500 [thread overview]
Message-ID: <20200116164300.6705-164-sashal@kernel.org> (raw)
In-Reply-To: <20200116164300.6705-1-sashal@kernel.org>
From: John Fastabend <john.fastabend@gmail.com>
[ Upstream commit 8163999db445021f2651a8a47b5632483e8722ea ]
Report from Dan Carpenter,
net/core/skmsg.c:792 sk_psock_write_space()
error: we previously assumed 'psock' could be null (see line 790)
net/core/skmsg.c
789 psock = sk_psock(sk);
790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
Check for NULL
791 schedule_work(&psock->work);
792 write_space = psock->saved_write_space;
^^^^^^^^^^^^^^^^^^^^^^^^
793 rcu_read_unlock();
794 write_space(sk);
Ensure psock dereference on line 792 only occurs if psock is not null.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/skmsg.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 0675d022584e..ded2d5227678 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -793,15 +793,18 @@ static void sk_psock_strp_data_ready(struct sock *sk)
static void sk_psock_write_space(struct sock *sk)
{
struct sk_psock *psock;
- void (*write_space)(struct sock *sk);
+ void (*write_space)(struct sock *sk) = NULL;
rcu_read_lock();
psock = sk_psock(sk);
- if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
- schedule_work(&psock->work);
- write_space = psock->saved_write_space;
+ if (likely(psock)) {
+ if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
+ schedule_work(&psock->work);
+ write_space = psock->saved_write_space;
+ }
rcu_read_unlock();
- write_space(sk);
+ if (write_space)
+ write_space(sk);
}
int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
--
2.20.1
next prev parent reply other threads:[~2020-01-16 19:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200116164300.6705-1-sashal@kernel.org>
2020-01-16 16:40 ` [PATCH AUTOSEL 5.4 049/205] net: netsec: Correct dma sync for XDP_TX frames Sasha Levin
2020-01-16 16:40 ` [PATCH AUTOSEL 5.4 077/205] libbpf: Fix compatibility for kernels without need_wakeup Sasha Levin
2020-01-16 16:40 ` [PATCH AUTOSEL 5.4 080/205] libbpf: Don't use kernel-side u32 type in xsk.c Sasha Levin
2020-01-16 16:41 ` [PATCH AUTOSEL 5.4 111/205] libbpf: Fix memory leak/double free issue Sasha Levin
2020-01-16 16:41 ` [PATCH AUTOSEL 5.4 112/205] libbpf: Fix potential overflow issue Sasha Levin
2020-01-16 16:41 ` [PATCH AUTOSEL 5.4 113/205] libbpf: Fix another potential overflow issue in bpf_prog_linfo Sasha Levin
2020-01-16 16:41 ` [PATCH AUTOSEL 5.4 114/205] libbpf: Make btf__resolve_size logic always check size error condition Sasha Levin
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 155/205] libbpf: Fix call relocation offset calculation bug Sasha Levin
2020-01-16 16:42 ` Sasha Levin [this message]
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 172/205] xdp: Fix cleanup on map free for devmap_hash map type Sasha Levin
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 179/205] bpf: Support pre-2.25-binutils objcopy for vmlinux BTF Sasha Levin
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 180/205] libbpf: Fix Makefile' libbpf symbol mismatch diagnostic Sasha Levin
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 186/205] bpf: Force .BTF section start to zero when dumping from vmlinux Sasha Levin
2020-01-16 16:42 ` [PATCH AUTOSEL 5.4 191/205] samples/bpf: Fix broken xdp_rxq_info due to map order assumptions Sasha Levin
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