diff options
| author | Wang Yufen <wangyufen@huawei.com> | 2022-03-04 16:11:43 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-03-15 16:43:31 +0100 |
| commit | 9c34e38c4a870eb30b13f42f5b44f42e9d19ccb8 (patch) | |
| tree | 6890c6e02a6c0a56dd0bc943c6a22d03da9e73c3 /net/core/skmsg.c | |
| parent | 938d3480b92fa5e454b7734294f12a7b75126f09 (diff) | |
bpf, sockmap: Fix memleak in tcp_bpf_sendmsg while sk msg is full
If tcp_bpf_sendmsg() is running while sk msg is full. When sk_msg_alloc()
returns -ENOMEM error, tcp_bpf_sendmsg() goes to wait_for_memory. If partial
memory has been alloced by sk_msg_alloc(), that is, msg_tx->sg.size is
greater than osize after sk_msg_alloc(), memleak occurs. To fix we use
sk_msg_trim() to release the allocated memory, then goto wait for memory.
Other call paths of sk_msg_alloc() have the similar issue, such as
tls_sw_sendmsg(), so handle sk_msg_trim logic inside sk_msg_alloc(),
as Cong Wang suggested.
This issue can cause the following info:
WARNING: CPU: 3 PID: 7950 at net/core/stream.c:208 sk_stream_kill_queues+0xd4/0x1a0
Call Trace:
<TASK>
inet_csk_destroy_sock+0x55/0x110
__tcp_close+0x279/0x470
tcp_close+0x1f/0x60
inet_release+0x3f/0x80
__sock_release+0x3d/0xb0
sock_close+0x11/0x20
__fput+0x92/0x250
task_work_run+0x6a/0xa0
do_exit+0x33b/0xb60
do_group_exit+0x2f/0xa0
get_signal+0xb6/0x950
arch_do_signal_or_restart+0xac/0x2a0
exit_to_user_mode_prepare+0xa9/0x200
syscall_exit_to_user_mode+0x12/0x30
do_syscall_64+0x46/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
WARNING: CPU: 3 PID: 2094 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260
Call Trace:
<TASK>
__sk_destruct+0x24/0x1f0
sk_psock_destroy+0x19b/0x1c0
process_one_work+0x1b3/0x3c0
kthread+0xe6/0x110
ret_from_fork+0x22/0x30
</TASK>
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220304081145.2037182-3-wangyufen@huawei.com
Diffstat (limited to 'net/core/skmsg.c')
| -rw-r--r-- | net/core/skmsg.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 929a2b096b04..cc381165ea08 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -27,6 +27,7 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, int elem_first_coalesce) { struct page_frag *pfrag = sk_page_frag(sk); + u32 osize = msg->sg.size; int ret = 0; len -= msg->sg.size; @@ -35,13 +36,17 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, u32 orig_offset; int use, i; - if (!sk_page_frag_refill(sk, pfrag)) - return -ENOMEM; + if (!sk_page_frag_refill(sk, pfrag)) { + ret = -ENOMEM; + goto msg_trim; + } orig_offset = pfrag->offset; use = min_t(int, len, pfrag->size - orig_offset); - if (!sk_wmem_schedule(sk, use)) - return -ENOMEM; + if (!sk_wmem_schedule(sk, use)) { + ret = -ENOMEM; + goto msg_trim; + } i = msg->sg.end; sk_msg_iter_var_prev(i); @@ -71,6 +76,10 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, } return ret; + +msg_trim: + sk_msg_trim(sk, msg, osize); + return ret; } EXPORT_SYMBOL_GPL(sk_msg_alloc); |