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| author |   John Fastabend <john.fastabend@gmail.com> | 2019-11-21 08:25:09 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-11-21 13:43:45 -0800 |
| commit | 8163999db445021f2651a8a47b5632483e8722ea (patch) | |
| tree | 044f73c60b4d6d2becf9a03c5c78170d7dbe1e98 /net | |
| parent | audit: Move audit_log_task declaration under CONFIG_AUDITSYSCALL (diff) | |
| download | linux-dev-8163999db445021f2651a8a47b5632483e8722ea.tar.xz linux-dev-8163999db445021f2651a8a47b5632483e8722ea.zip | |
bpf: skmsg, fix potential psock NULL pointer dereference
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skmsg.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index ad31e4e53d0a..a469d2124f3f 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) |