[rds-devel] [PATCH net] rds: fix refcount bug in rds_sock_addref

[David Miller]

From: Eric Dumazet <edumazet at google.com>
Date: Thu, 31 Jan 2019 08:47:10 -0800

> syzbot was able to catch a bug in rds [1]
> 
> The issue here is that the socket might be found in a hash table
> but that its refcount has already be set to 0 by another cpu.
> 
> We need to use refcount_inc_not_zero() to be safe here.
 ...
> Fixes: cc4dfb7f70a3 ("rds: fix two RCU related problems")
> Signed-off-by: Eric Dumazet <edumazet at google.com>
> Reported-by: syzbot <syzkaller at googlegroups.com>

Applied and queued up for -stable, thanks Eric.