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authorAlexey Dobriyan <adobriyan@sw.ru>2007-09-18 22:46:27 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-09-19 11:24:17 -0700
commitefc63c4fb0f95865907472d1c6bc0cfea9ee156b (patch)
tree197650d8698f62c4886305e859cfbbf16aada5fc /kernel
parent019ad4a0a60b09022945273848b5a686e39a78aa (diff)
downloadlinux-efc63c4fb0f95865907472d1c6bc0cfea9ee156b.tar.gz
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/utsname.c2
1 files changed, 2 insertions, 0 deletions
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;
 }