From: Samuel Thibault <samuel.thibault@gnu.org>
To: bug-hurd@gnu.org
Cc: commit-hurd@gnu.org, libc-alpha@sourceware.org
Subject: Re: [hurd, commited] hurd: Use __trivfs_server_name instead of trivfs_server_name
Date: Sat, 1 Jan 2022 18:41:20 +0100 [thread overview]
Message-ID: <20220101174120.z7kh5zq4qdsbfnvt@begin> (raw)
In-Reply-To: <87tuenv016.fsf@mid.deneb.enyo.de>
Florian Weimer, le sam. 01 janv. 2022 18:27:49 +0100, a ecrit:
> > @@ -33,14 +33,14 @@ __getrandom (void *buffer, size_t length, unsigned int flags)
> > size_t amount_read;
> > int fd;
> >
> > - if (&trivfs_server_name && trivfs_server_name
> > - && trivfs_server_name[0] == 'r'
> > - && trivfs_server_name[1] == 'a'
> > - && trivfs_server_name[2] == 'n'
> > - && trivfs_server_name[3] == 'd'
> > - && trivfs_server_name[4] == 'o'
> > - && trivfs_server_name[5] == 'm'
> > - && trivfs_server_name[6] == '\0')
> > + if (&__trivfs_server_name && __trivfs_server_name
> > + && __trivfs_server_name[0] == 'r'
> > + && __trivfs_server_name[1] == 'a'
> > + && __trivfs_server_name[2] == 'n'
> > + && __trivfs_server_name[3] == 'd'
> > + && __trivfs_server_name[4] == 'o'
> > + && __trivfs_server_name[5] == 'm'
> > + && __trivfs_server_name[6] == '\0')
> > /* We are random, don't try to read ourselves! */
> > return length;
>
> How does this work? It's a new synbol name, so there's no definition,
> so the weak reference is always null.
It is peeking it from the program.
Basically the problem is that the random translator uses glibc, whose
malloc implementation started using /dev/random in glibc 2.34, thus
reading itself.
Samuel
next prev parent reply other threads:[~2022-01-01 17:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-01 16:53 Samuel Thibault
2022-01-01 17:27 ` Florian Weimer
2022-01-01 17:41 ` Samuel Thibault [this message]
2022-01-01 18:48 ` Florian Weimer
2022-01-01 18:58 ` Samuel Thibault
2022-01-01 19:02 ` Florian Weimer
2022-01-01 19:11 ` Samuel Thibault
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220101174120.z7kh5zq4qdsbfnvt@begin \
--to=samuel.thibault@gnu.org \
--cc=bug-hurd@gnu.org \
--cc=commit-hurd@gnu.org \
--cc=libc-alpha@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).