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From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, Liu Yong <[email protected]>
Cc: [email protected], io-uring <[email protected]>
Subject: Re: [PATCH] fs/io_uring.c: fix null ptr deference in io_send_recvmsg()
Date: Tue, 4 Aug 2020 07:27:15 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 8/4/20 7:18 AM, Pavel Begunkov wrote:
> On 04/08/2020 15:56, Liu Yong wrote:
>> In io_send_recvmsg(), there is no check for the req->file.
>> User can change the opcode from IORING_OP_NOP to IORING_OP_SENDMSG
>> through competition after the io_req_set_file().
> 
> After sqe->opcode is read and copied in io_init_req(), it only uses
> in-kernel req->opcode. Also, io_init_req() should check for req->file
> NULL, so shouldn't happen after.
> 
> Do you have a reproducer? What kernel version did you use?

Was looking at this too, and I'm guessing this is some 5.4 based kernel.
Unfortunately the oops doesn't include that information.

-- 
Jens Axboe


  reply	other threads:[~2020-08-04 13:27 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200804125637.GA22088@ubuntu>
2020-08-04 13:18 ` [PATCH] fs/io_uring.c: fix null ptr deference in io_send_recvmsg() Pavel Begunkov
2020-08-04 13:27   ` Jens Axboe [this message]
     [not found]     ` <CAGAoTxzadSphnE2aLsFKS04TjTKYVq2uLFgH9dvLPwWiyqEGEQ@mail.gmail.com>
2020-08-04 17:15       ` Jens Axboe
2020-08-04 21:55         ` Jens Axboe
2020-08-05  3:40           ` Liu Yong
2020-08-05  4:10             ` Jens Axboe

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