From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: jiri@resnulli.us, netdev@vger.kernel.org
Subject: Re: [PATCH net] net: get rid of an signed integer overflow in ip_idents_reserve()
Date: Thu, 22 Sep 2016 02:42:54 -0400 (EDT) [thread overview]
Message-ID: <20160922.024254.1880139496617528792.davem@davemloft.net> (raw)
In-Reply-To: <1474419977.23058.53.camel@edumazet-glaptop3.roam.corp.google.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 20 Sep 2016 18:06:17 -0700
> From: Eric Dumazet <edumazet@google.com>
>
> Jiri Pirko reported an UBSAN warning happening in ip_idents_reserve()
>
> [] UBSAN: Undefined behaviour in ./arch/x86/include/asm/atomic.h:156:11
> [] signed integer overflow:
> [] -2117905507 + -695755206 cannot be represented in type 'int'
>
> Since we do not have uatomic_add_return() yet, use atomic_cmpxchg()
> so that the arithmetics can be done using unsigned int.
>
> Fixes: 04ca6973f7c1 ("ip: make IP identifiers less predictable")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Jiri Pirko <jiri@resnulli.us>
> ---
> David, Jiri, I removed the prandom_u32() stuff in favor of a traditional
> loop to meet stable requirements. Thanks !
Applied.
prev parent reply other threads:[~2016-09-22 6:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-20 12:00 UBSAN reports issue in ip_idents_reserve Jiri Pirko
2016-09-20 13:28 ` Eric Dumazet
2016-09-20 13:36 ` David Laight
2016-09-20 13:45 ` Eric Dumazet
2016-09-20 13:39 ` Jiri Pirko
2016-09-20 14:11 ` Eric Dumazet
2016-09-20 14:18 ` Eric Dumazet
2016-09-20 14:24 ` Eric Dumazet
2016-09-20 17:46 ` Jiri Pirko
2016-09-20 18:42 ` Eric Dumazet
2016-09-20 15:25 ` Eric Dumazet
2016-09-20 16:25 ` Jiri Pirko
2016-09-21 1:06 ` [PATCH net] net: get rid of an signed integer overflow in ip_idents_reserve() Eric Dumazet
2016-09-22 6:42 ` David Miller [this message]
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