diff options
| author | Zhang Yuchen <zhangyuchen.lcr@bytedance.com> | 2022-10-07 11:26:17 +0200 |
|---|---|---|
| committer | Corey Minyard <cminyard@mvista.com> | 2022-10-17 16:51:27 +0200 |
| commit | 36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9 (patch) | |
| tree | 524af04941f6353c70142118e940d96730279d68 /drivers/char | |
| parent | ipmi: fix long wait in unload when IPMI disconnect (diff) | |
| download | linux-36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9.tar.xz linux-36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9.zip | |
ipmi: fix memleak when unload ipmi driver
After the IPMI disconnect problem, the memory kept rising and we tried
to unload the driver to free the memory. However, only part of the
free memory is recovered after the driver is uninstalled. Using
ebpf to hook free functions, we find that neither ipmi_user nor
ipmi_smi_msg is free, only ipmi_recv_msg is free.
We find that the deliver_smi_err_response call in clean_smi_msgs does
the destroy processing on each message from the xmit_msg queue without
checking the return value and free ipmi_smi_msg.
deliver_smi_err_response is called only at this location. Adding the
free handling has no effect.
To verify, try using ebpf to trace the free function.
$ bpftrace -e 'kretprobe:ipmi_alloc_recv_msg {printf("alloc rcv
%p\n",retval);} kprobe:free_recv_msg {printf("free recv %p\n",
arg0)} kretprobe:ipmi_alloc_smi_msg {printf("alloc smi %p\n",
retval);} kprobe:free_smi_msg {printf("free smi %p\n",arg0)}'
Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com>
Message-Id: <20221007092617.87597-4-zhangyuchen.lcr@bytedance.com>
[Fixed the comment above handle_one_recv_msg().]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/ipmi/ipmi_msghandler.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 49a1707693c9..d5ee52be176d 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -3704,12 +3704,16 @@ static void deliver_smi_err_response(struct ipmi_smi *intf, struct ipmi_smi_msg *msg, unsigned char err) { + int rv; msg->rsp[0] = msg->data[0] | 4; msg->rsp[1] = msg->data[1]; msg->rsp[2] = err; msg->rsp_size = 3; - /* It's an error, so it will never requeue, no need to check return. */ - handle_one_recv_msg(intf, msg); + + /* This will never requeue, but it may ask us to free the message. */ + rv = handle_one_recv_msg(intf, msg); + if (rv == 0) + ipmi_free_smi_msg(msg); } static void cleanup_smi_msgs(struct ipmi_smi *intf) |