2021-10-22 03:28:14

by Wang Hai

Subject: [PATCH] Bluetooth: cmtp: fix possible panic when cmtp_init_sockets() fails

I got a kernel BUG report when doing fault injection test:

------------[ cut here ]------------
kernel BUG at lib/list_debug.c:45!
...
RIP: 0010:__list_del_entry_valid.cold+0x12/0x4d
...
Call Trace:
proto_unregister+0x83/0x220
cmtp_cleanup_sockets+0x37/0x40 [cmtp]
cmtp_exit+0xe/0x1f [cmtp]
do_syscall_64+0x35/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae

If cmtp_init_sockets() in cmtp_init() fails, cmtp_init() still returns
success. This will cause a kernel bug when accessing uncreated ctmp
related data when the module exits.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Wang Hai <[email protected]>
---
net/bluetooth/cmtp/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
index 0a2d78e811cf..ccf48f50afdf 100644
--- a/net/bluetooth/cmtp/core.c
+++ b/net/bluetooth/cmtp/core.c
@@ -499,11 +499,13 @@ int cmtp_get_conninfo(struct cmtp_conninfo *ci)

static int __init cmtp_init(void)
{
+ int err;
+
BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);

- cmtp_init_sockets();
+ err = cmtp_init_sockets();

- return 0;
+ return err;
}

static void __exit cmtp_exit(void)
--
2.25.1

2021-10-22 04:49:36

by Marcel Holtmann

Subject: Re: [PATCH] Bluetooth: cmtp: fix possible panic when cmtp_init_sockets() fails

Hi Wang,

> I got a kernel BUG report when doing fault injection test:
>
> ------------[ cut here ]------------
> kernel BUG at lib/list_debug.c:45!
> ...
> RIP: 0010:__list_del_entry_valid.cold+0x12/0x4d
> ...
> Call Trace:
> proto_unregister+0x83/0x220
> cmtp_cleanup_sockets+0x37/0x40 [cmtp]
> cmtp_exit+0xe/0x1f [cmtp]
> do_syscall_64+0x35/0xb0
> entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> If cmtp_init_sockets() in cmtp_init() fails, cmtp_init() still returns
> success. This will cause a kernel bug when accessing uncreated ctmp
> related data when the module exits.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Wang Hai <[email protected]>
> ---
> net/bluetooth/cmtp/core.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
> index 0a2d78e811cf..ccf48f50afdf 100644
> --- a/net/bluetooth/cmtp/core.c
> +++ b/net/bluetooth/cmtp/core.c
> @@ -499,11 +499,13 @@ int cmtp_get_conninfo(struct cmtp_conninfo *ci)
>
> static int __init cmtp_init(void)
> {
> + int err;
> +
> BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);
>
> - cmtp_init_sockets();
> + err = cmtp_init_sockets();
>
> - return 0;
> + return err;
> }

just do return cmtp_init_sockets();

Regards

Marcel