linux-kernel - [PATCH] Reset current->pdeath_signal on SUID binary execution

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Date:	Fri, 17 Aug 2007 21:47:58 +0200
From:	Marcel Holtmann <marcel@...tmann.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org, mtk-manpages@....net
Subject: [PATCH] Reset current->pdeath_signal on SUID binary execution

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.

>>From comments it seems that we have to also reset pdeath_signal inside
LSM when it comes to capability-raised executes, but I must admit that I
got lost there.

Regards

Marcel

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