Description: can: bcm: fix infoleak in struct bcm_msg_head
References:
 https://lore.kernel.org/netdev/trinity-87eaea25-2a7d-4aa9-92a5-269b822e5d95-1623609211076@3c-app-gmx-bs04/T/
 https://www.openwall.com/lists/oss-security/2021/06/15/1
 https://github.com/nrb547/kernel-exploitation/tree/main/cve-2021-34693
Notes:
Bugs:
upstream: released (5.13-rc7) [5e87ddbe3942e27e939bdc02deb8579b0cbd8ecc]
5.10-upstream-stable: released (5.10.46) [acb755be1f7adb204dcedc4d3b204ef098628623]
4.19-upstream-stable: released (4.19.196) [8899857d7e450805e6410de5004126491f197146]
4.9-upstream-stable: released (4.9.274) [d240a28396e08023987384ce80bc940bb38ac779]
sid: released (5.10.46-1)
4.19-buster-security: released (4.19.194-3) [bugfix/all/can-bcm-fix-infoleak-in-struct-bcm_msg_head.patch]
4.9-stretch-security: released (4.9.272-2) [bugfix/all/can-bcm-fix-infoleak-in-struct-bcm_msg_head.patch]