CVE-2023-53109

In the Linux kernel, the following vulnerability has been resolved:

net: tunnels: annotate lockless accesses to dev->needed_headroom

IP tunnels can apparently update dev->needed_headroom in their xmit path.

This patch takes care of three tunnels xmit, and also the core LLRESERVEDSPACE() and LLRESERVEDSPACE_EXTRA() helpers.

More changes might be needed for completeness.

BUG: KCSAN: data-race in iptunnelxmit / iptunnelxmit

read to 0xffff88815b9da0ec of 2 bytes by task 888 on cpu 1: iptunnelxmit+0x1270/0x1730 net/ipv4/iptunnel.c:803 _grexmit net/ipv4/ipgre.c:469 [inline] ipgrexmit+0x516/0x570 net/ipv4/ipgre.c:661 _netdevstartxmit include/linux/netdevice.h:4881 [inline] netdevstartxmit include/linux/netdevice.h:4895 [inline] xmitone net/core/dev.c:3580 [inline] devhardstartxmit+0x127/0x400 net/core/dev.c:3596 _devqueuexmit+0x1007/0x1eb0 net/core/dev.c:4246 devqueuexmit include/linux/netdevice.h:3051 [inline] neighdirectoutput+0x17/0x20 net/core/neighbour.c:1623 neighoutput include/net/neighbour.h:546 [inline] ipfinishoutput2+0x740/0x840 net/ipv4/ipoutput.c:228 ipfinishoutput+0xf4/0x240 net/ipv4/ipoutput.c:316 NFHOOKCOND include/linux/netfilter.h:291 [inline] ipoutput+0xe5/0x1b0 net/ipv4/ipoutput.c:430 dstoutput include/net/dst.h:444 [inline] iplocalout+0x64/0x80 net/ipv4/ipoutput.c:126 iptunnelxmit+0x34a/0x4b0 net/ipv4/iptunnelcore.c:82 iptunnelxmit+0x1451/0x1730 net/ipv4/iptunnel.c:813 _grexmit net/ipv4/ipgre.c:469 [inline] ipgrexmit+0x516/0x570 net/ipv4/ipgre.c:661 _netdevstartxmit include/linux/netdevice.h:4881 [inline] netdevstartxmit include/linux/netdevice.h:4895 [inline] xmitone net/core/dev.c:3580 [inline] devhardstartxmit+0x127/0x400 net/core/dev.c:3596 _devqueuexmit+0x1007/0x1eb0 net/core/dev.c:4246 devqueuexmit include/linux/netdevice.h:3051 [inline] neighdirectoutput+0x17/0x20 net/core/neighbour.c:1623 neighoutput include/net/neighbour.h:546 [inline] ipfinishoutput2+0x740/0x840 net/ipv4/ipoutput.c:228 ipfinishoutput+0xf4/0x240 net/ipv4/ipoutput.c:316 NFHOOKCOND include/linux/netfilter.h:291 [inline] ipoutput+0xe5/0x1b0 net/ipv4/ipoutput.c:430 dstoutput include/net/dst.h:444 [inline] iplocalout+0x64/0x80 net/ipv4/ipoutput.c:126 iptunnelxmit+0x34a/0x4b0 net/ipv4/iptunnelcore.c:82 iptunnelxmit+0x1451/0x1730 net/ipv4/iptunnel.c:813 _grexmit net/ipv4/ipgre.c:469 [inline] ipgrexmit+0x516/0x570 net/ipv4/ipgre.c:661 _netdevstartxmit include/linux/netdevice.h:4881 [inline] netdevstartxmit include/linux/netdevice.h:4895 [inline] xmitone net/core/dev.c:3580 [inline] devhardstartxmit+0x127/0x400 net/core/dev.c:3596 _devqueuexmit+0x1007/0x1eb0 net/core/dev.c:4246 devqueuexmit include/linux/netdevice.h:3051 [inline] neighdirectoutput+0x17/0x20 net/core/neighbour.c:1623 neighoutput include/net/neighbour.h:546 [inline] ipfinishoutput2+0x740/0x840 net/ipv4/ipoutput.c:228 ipfinishoutput+0xf4/0x240 net/ipv4/ipoutput.c:316 NFHOOKCOND include/linux/netfilter.h:291 [inline] ipoutput+0xe5/0x1b0 net/ipv4/ipoutput.c:430 dstoutput include/net/dst.h:444 [inline] iplocalout+0x64/0x80 net/ipv4/ipoutput.c:126 iptunnelxmit+0x34a/0x4b0 net/ipv4/iptunnelcore.c:82 iptunnelxmit+0x1451/0x1730 net/ipv4/iptunnel.c:813 _grexmit net/ipv4/ipgre.c:469 [inline] ipgrexmit+0x516/0x570 net/ipv4/ipgre.c:661 _netdevstartxmit include/linux/netdevice.h:4881 [inline] netdevstartxmit include/linux/netdevice.h:4895 [inline] xmitone net/core/dev.c:3580 [inline] devhardstartxmit+0x127/0x400 net/core/dev.c:3596 _devqueuexmit+0x1007/0x1eb0 net/core/dev.c:4246 devqueuexmit include/linux/netdevice.h:3051 [inline] neighdirectoutput+0x17/0x20 net/core/neighbour.c:1623 neighoutput include/net/neighbour.h:546 [inline] ipfinishoutput2+0x740/0x840 net/ipv4/ipoutput.c:228 ipfinishoutput+0xf4/0x240 net/ipv4/ipoutput.c:316 NFHOOKCOND include/linux/netfilter.h:291 [inline] ipoutput+0xe5/0x1b0 net/i ---truncated---