From: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
To: Marcel Holtmann <marcel@holtmann.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, mtk-manpages@gmx.net
Subject: Re: [PATCH] Reset current->pdeath_signal on SUID binary execution
Date: Mon, 23 Apr 2012 21:34:27 +1200 [thread overview]
Message-ID: <CAKgNAkgJYjACsoOKhFZirPW_SrZ9Rwn7MMch_1GbrrNWFxhu+w@mail.gmail.com> (raw)
In-Reply-To: <1187380078.6698.448.camel@violet>
Marcel,
On Sat, Aug 18, 2007 at 7:47 AM, Marcel Holtmann <marcel@holtmann.org> wrote:
> Hi Linus,
>
> the attached patch fixes a flaw in the "parent process death signal"
> when executing SUID binaries. An unprivileged user may send arbitrary
> signal to a child process even if it is running with higher privileges.
>
> The idea to fix this issue is to reset pdeath_signal not only on fork,
> but also on the execution of a SUID binary.
>
> Michael, if we fix it this way, then the prctl() manual page should
> reflect that behavior.
For man-pages-3.40, I applied the patch below.
Cheers,
Michael
--- a/man2/prctl.2
+++ b/man2/prctl.2
@@ -220,7 +220,9 @@ in the range 1..maxsig, or 0 to clear).
This is the signal that the calling process will get when its
parent dies.
This value is cleared for the child of a
-.BR fork (2).
+.BR fork (2)
+and (since Linux 2.5.36 / 2.6.23)
+when execing a set-user_ID or set-group-ID binary.
.TP
.BR PR_GET_PDEATHSIG " (since Linux 2.3.15)"
Return the current value of the parent process death signal,
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface"; http://man7.org/tlpi/
prev parent reply other threads:[~2012-04-23 9:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-17 19:47 [PATCH] Reset current->pdeath_signal on SUID binary execution Marcel Holtmann
2007-08-23 8:21 ` Marcel Holtmann
2007-08-27 15:32 ` Michael Kerrisk
2007-08-27 16:28 ` Linus Torvalds
2012-04-23 9:34 ` Michael Kerrisk (man-pages) [this message]
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