Fix a bug in the current random UUID generator:
Section 4.1.6 of RFC 4122 states regarding the "NodeID" of a UUID:
: For systems with no IEEE address, a randomly or pseudo-randomly
: generated value may be used; see Section 4.5. The multicast bit must
: be set in such addresses, in order that they will never conflict with
: addresses obtained from network cards.
So up to now it was just pure ("random") luck if this bit was set or not.
This tiny patch sets the bit explicitely.
Signed-off-by: Helge Deller <[email protected]>
CC: [email protected]
random.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1157,6 +1158,8 @@ void generate_random_uuid(unsigned char uuid_out[16])
uuid_out[6] = (uuid_out[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
uuid_out[8] = (uuid_out[8] & 0x3F) | 0x80;
+ /* Set multicast bit to avoid conflicts with NIC MAC addresses */
+ uuid_out[10] |= 0x80;
}
EXPORT_SYMBOL(generate_random_uuid);
-
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