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Date: Sun, 7 Dec 2003 14:39:06 +0100
From: Alex Riesen <fork0@users.sourceforge.net>
To: William Lee Irwin III <wli@holomorphy.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
       Ulrich Drepper <drepper@redhat.com>
Subject: Re: [PATCH] FIx 'noexec' behavior
Message-ID: <20031207133906.GA1140@steel.home>
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	Ulrich Drepper <drepper@redhat.com>
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On 2003-12-07 12:17:37, wli wrote:
> You took a fault in do_mmap_pgoff().
...
> +		if (file->f_vfsmnt && (prot & PROT_EXEC)) {
> +			if (file->f_vfsmnt->mnt_flags & MNT_NOEXEC)
> +				return -EPERM;
> +		}

I had to put a check for 'file' (as Ulrich suggested).
Otherwise it deadlocks again.
Is it possible for ->f_vfsmnt to be NULL at all? Should it be tested?

diff -Nru a/mm/mmap.c b/mm/mmap.c
--- a/mm/mmap.c Sun Dec  7 14:37:33 2003
+++ b/mm/mmap.c Sun Dec  7 14:37:33 2003
@@ -478,7 +478,7 @@
        if (file && (!file->f_op || !file->f_op->mmap))
                return -ENODEV;
 
-       if ((prot & PROT_EXEC) && (file->f_vfsmnt->mnt_flags & MNT_NOEXEC))
+       if ((prot & PROT_EXEC) && file && (file->f_vfsmnt->mnt_flags & MNT_NOEXEC))
                return -EPERM;
 
        if (!len)