linux-ext4 - [Bug 61601] rootflags=noatime causes kernel panic when booting without initrd.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 11 Aug 2014 05:06:13 +0000
From:	bugzilla-daemon@...zilla.kernel.org
To:	linux-ext4@...r.kernel.org
Subject: [Bug 61601] rootflags=noatime causes kernel panic when booting
 without initrd.

https://bugzilla.kernel.org/show_bug.cgi?id=61601

Theodore Tso <tytso@....edu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tytso@....edu

--- Comment #10 from Theodore Tso <tytso@....edu> ---
Here's what's going on.   There are some mount flags that are parsed by the
userspace mount program, and translated to an integer field "mountflags" in the
mount(2) system call.   See the man page for mount(2) for more details; see the
flags MS_NOATIME, MS_NOEXEC, MS_NOSUID, etc.  They are described in the
mount(8) system call in the section "FILESYSTEM INDEPENDENT MOUNT OPTIONS".

If you are using an initrd, the rootflags boot line command is handled by the
userspace mount program; the initrd is responsible for mounting the root file
system, and it does so using mount(8).

However, if you are not using an initrd, then the mount flags are handled by
/usr/src/linux/init/do_mounts.c, and the kernel code simply doesn't handle
converting "noatime" into MS_NOATIME and then or'ing it into root_mountflags.

The simplest workaround is to add in your init scripts the command:

mount -o remount,noatime /

you could combine this with the init script command which remounts the root
file system read-only, i.e.:   mount -o remount,rw,noatime /

P.S.  Ignore Nick's comment in #9.  He's guessing, and he doesn't know what
he's doing.  He's been banned from LKML, but unfortunately he hasn't been
banned from the kernel bugzilla yet.  It's one thing when he's wasting
maintainers' time, but when he's confusing and adding negative value to users
who are asking for help, it's definitely not ok.   We'll have to remedy
that....

See https://plus.google.com/+TheodoreTso/posts/ELVf6FmuY2N for more details.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html