From: Dave Jones <davej@redhat.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: mtk.manpages@gmail.com, linux-mm@kvack.org,
Linus Torvalds <torvalds@linux-foundation.org>,
zohar@linux.vnet.ibm.com
Subject: ima_mmap_file returning 0 to userspace as mmap result.
Date: Wed, 4 Jun 2014 19:31:22 -0400 [thread overview]
Message-ID: <20140604233122.GA19838@redhat.com> (raw)
I just noticed that trinity was freaking out in places when mmap was
returning zero. This surprised me, because I had the mmap_min_addr
sysctl set to 64k, so it wasn't a MAP_FIXED mapping that did it.
There's no mention of this return value in the man page, so I dug
into the kernel code, and it appears that we do..
sys_mmap
vm_mmap_pgoff
security_mmap_file
ima_file_mmap <- returns 0 if not PROT_EXEC
and then the 0 gets propagated up as a retval all the way to userspace.
It smells to me like we might be violating a standard or two here, and
instead of 0 ima should be returning -Esomething
thoughts?
Dave
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Dave Jones <davej@redhat.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: mtk.manpages@gmail.com, linux-mm@kvack.org,
Linus Torvalds <torvalds@linux-foundation.org>,
zohar@linux.vnet.ibm.com
Subject: ima_mmap_file returning 0 to userspace as mmap result.
Date: Wed, 4 Jun 2014 19:31:22 -0400 [thread overview]
Message-ID: <20140604233122.GA19838@redhat.com> (raw)
I just noticed that trinity was freaking out in places when mmap was
returning zero. This surprised me, because I had the mmap_min_addr
sysctl set to 64k, so it wasn't a MAP_FIXED mapping that did it.
There's no mention of this return value in the man page, so I dug
into the kernel code, and it appears that we do..
sys_mmap
vm_mmap_pgoff
security_mmap_file
ima_file_mmap <- returns 0 if not PROT_EXEC
and then the 0 gets propagated up as a retval all the way to userspace.
It smells to me like we might be violating a standard or two here, and
instead of 0 ima should be returning -Esomething
thoughts?
Dave
next reply other threads:[~2014-06-04 23:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-04 23:31 Dave Jones [this message]
2014-06-04 23:31 ` ima_mmap_file returning 0 to userspace as mmap result Dave Jones
2014-06-05 4:40 ` Michael Kerrisk (man-pages)
2014-06-05 4:40 ` Michael Kerrisk (man-pages)
2014-06-05 15:56 ` Dave Jones
2014-06-05 15:56 ` Dave Jones
2014-06-05 16:20 ` Dave Jones
2014-06-05 16:20 ` Dave Jones
2014-06-06 1:49 ` Mimi Zohar
2014-06-06 1:49 ` Mimi Zohar
2014-06-06 1:56 ` Dave Jones
2014-06-06 1:56 ` Dave Jones
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=20140604233122.GA19838@redhat.com \
--to=davej@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mtk.manpages@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=zohar@linux.vnet.ibm.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.