Re: net/can: warning in bcm_connect/proc_register

On Mon, Oct 24, 2016 at 9:21 AM, Andrey Konovalov [off-list ref] wrote:

Hi,

I've got the following error report while running the syzkaller fuzzer:

WARNING: CPU: 0 PID: 32451 at fs/proc/generic.c:345 proc_register+0x25e/0x300
proc_dir_entry 'can-bcm/249757' already registered
Kernel panic - not syncing: panic_on_warn set ...

Looks like we have two problems here:

1) A check for bo->bcm_proc_read != NULL seems missing
2) We need to lock the sock in bcm_connect().

I will work on a patch. Meanwhile, it would help a lot if you could provide
a reproducer.

Thanks!