On Fri, Feb 2, 2018 at 1:27 PM, Eric Dumazet <eric.duma...@gmail.com> wrote:
> From: Eric Dumazet <eduma...@google.com>
>
> reuseport_add_sock() needs to deal with attaching a socket having
> its own sk_reuseport_cb, after a prior
> setsockopt(SO_ATTACH_REUSEPORT_?BPF)
>
> Without this fix, not only a WARN_ONCE() was issued, but we were also
> leaking memory.
>
> Thanks to sysbot and Eric Biggers for providing us nice C repros.
>
> ------------[ cut here ]------------
> socket already in reuseport group
> WARNING: CPU: 0 PID: 3496 at net/core/sock_reuseport.c:119
> reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117
> Kernel panic - not syncing: panic_on_warn set ...
>
> CPU: 0 PID: 3496 Comm: syzkaller869503 Not tainted 4.15.0-rc6+ #245
> Hardware name: Google Google Compute Engine/Google Compute Engine,
> BIOS
> Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:17 [inline]
> dump_stack+0x194/0x257 lib/dump_stack.c:53
> panic+0x1e4/0x41c kernel/panic.c:183
> __warn+0x1dc/0x200 kernel/panic.c:547
> report_bug+0x211/0x2d0 lib/bug.c:184
> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
> fixup_bug arch/x86/kernel/traps.c:247 [inline]
> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079
>
> Fixes: ef456144da8e ("soreuseport: define reuseport groups")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: syzbot+c0ea2226f77a42936...@syzkaller.appspotmail.com
Clever fix, thanks Eric(s)!
Acked-by: Craig Gallek <kr...@google.com>
