From efc63c4fb0f95865907472d1c6bc0cfea9ee156b Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@sw.ru>
Date: Tue, 18 Sep 2007 22:46:27 -0700
Subject: [PATCH] Fix UTS corruption during clone(CLONE_NEWUTS)
struct utsname is copied from master one without any exclusion.
Here is sample output from one proggie doing
sethostname("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
sethostname("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
and another
clone(,, CLONE_NEWUTS, ...)
uname()
hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaabbbbb'
hostname = 'bbbaaaaaaaaaaaaaaaaaaaaaaaaaaa'
hostname = 'aaaaaaaabbbbbbbbbbbbbbbbbbbbbb'
hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaaabbbb'
hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaabb'
hostname = 'aaabbbbbbbbbbbbbbbbbbbbbbbbbbb'
hostname = 'bbbbbbbbbbbbbbbbaaaaaaaaaaaaaa'
Hostname is sometimes corrupted.
Yes, even _the_ simplest namespace activity had bug in it. :-(
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
kernel/utsname.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 9d8180a0f0d8..816d7b24fa03 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -28,7 +28,9 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
if (!ns)
return ERR_PTR(-ENOMEM);
+ down_read(&uts_sem);
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+ up_read(&uts_sem);
kref_init(&ns->kref);
return ns;
}
--
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