From: Jakub Kicinski <kuba@kernel.org>
To: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Cc: David Miller <davem@davemloft.net>,
netdev@vger.kernel.org, secdev@chelsio.com
Subject: Re: [PATCH net-next] net/tls: fix race condition causing kernel panic
Date: Thu, 21 May 2020 11:56:23 -0700 [thread overview]
Message-ID: <20200521115623.134eeb83@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <0a5d0864-2830-6bc8-05e8-232d10c0f333@chelsio.com>
On Thu, 21 May 2020 14:28:27 +0530 Vinay Kumar Yadav wrote:
> Considering the lock in fix ("pending" is local variable), when writer reads
> pending == 0 [pending = atomic_read(&ctx->encrypt_pending); --> from tls_sw_sendmsg()],
> that means encrypt complete() [from tls_encrypt_done()] is already called.
Please indulge me with full sentences. I can't parse this.
> and if pending == 1 [pending = atomic_read(&ctx->encrypt_pending); --> from tls_sw_sendmsg()],
> that means writer is going to wait for atomic_dec_return(&ctx->decrypt_pending) and
> complete() [from tls_encrypt_done()] to be called atomically.
>
> This way, writer is not going to proceed to encrypt next record on CPU0 without complete().
next prev parent reply other threads:[~2020-05-21 18:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 7:43 [PATCH net-next] net/tls: fix race condition causing kernel panic Vinay Kumar Yadav
2020-05-19 19:16 ` David Miller
2020-05-20 17:09 ` Vinay Kumar Yadav
2020-05-20 19:58 ` Jakub Kicinski
2020-05-21 8:58 ` Vinay Kumar Yadav
2020-05-21 18:56 ` Jakub Kicinski [this message]
2020-05-21 20:32 ` Vinay Kumar Yadav
2020-05-21 21:40 ` Jakub Kicinski
[not found] ` <bbcfb6c7-8e98-63a1-4ff6-d185bdcf4708@chelsio.com>
2020-05-21 21:38 ` David Miller
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