From: Matthew Wilcox <[email protected]>
To: Pavel Begunkov <[email protected]>
Cc: yangerkun <[email protected]>,
[email protected], [email protected], [email protected]
Subject: Re: [PATCH 1/2] io_uring: fix UAF for personality_idr
Date: Mon, 8 Mar 2021 14:12:39 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On Mon, Mar 08, 2021 at 01:54:14PM +0000, Pavel Begunkov wrote:
> > + ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds,
> > + XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
>
> ids are >=1, because 0 is kind of a reserved value for io_uring, so I guess
>
> XA_LIMIT(1, USHRT_MAX)
+ xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
takes care of not being able to allocate ID 0.
next prev parent reply other threads:[~2021-03-08 14:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-08 6:59 [PATCH 1/2] io_uring: fix UAF for personality_idr yangerkun
2021-03-08 6:59 ` [PATCH 2/2] io_uring: fix UAF for io_buffer_idr yangerkun
2021-03-08 7:04 ` [PATCH 1/2] io_uring: fix UAF for personality_idr yangerkun
2021-03-08 10:46 ` Pavel Begunkov
2021-03-08 13:20 ` Matthew Wilcox
2021-03-08 13:54 ` Pavel Begunkov
2021-03-08 14:12 ` Matthew Wilcox [this message]
2021-03-08 13:57 ` Stefan Metzmacher
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