linux_dsm_epyc7002/include
Vishwanath Pai 596cf3fe58 netfilter: ipset: fix race condition in ipset save, swap and delete
This fix adds a new reference counter (ref_netlink) for the struct ip_set.
The other reference counter (ref) can be swapped out by ip_set_swap and we
need a separate counter to keep track of references for netlink events
like dump. Using the same ref counter for dump causes a race condition
which can be demonstrated by the following script:

ipset create hash_ip1 hash:ip family inet hashsize 1024 maxelem 500000 \
counters
ipset create hash_ip2 hash:ip family inet hashsize 300000 maxelem 500000 \
counters
ipset create hash_ip3 hash:ip family inet hashsize 1024 maxelem 500000 \
counters

ipset save &

ipset swap hash_ip3 hash_ip2
ipset destroy hash_ip3 /* will crash the machine */

Swap will exchange the values of ref so destroy will see ref = 0 instead of
ref = 1. With this fix in place swap will not succeed because ipset save
still has ref_netlink on the set (ip_set_swap doesn't swap ref_netlink).

Both delete and swap will error out if ref_netlink != 0 on the set.

Note: The changes to *_head functions is because previously we would
increment ref whenever we called these functions, we don't do that
anymore.

Reviewed-by: Joshua Hunt <johunt@akamai.com>
Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:57:45 +02:00
..
acpi
asm-generic Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-24 09:36:18 -07:00
clocksource
crypto
drm
dt-bindings The clk changes for this release cycle are mostly dominated by 2016-03-23 06:06:45 -07:00
keys
kvm
linux netfilter: ipset: fix race condition in ipset save, swap and delete 2016-03-28 17:57:45 +02:00
math-emu
media
memory
misc
net net: ping: make ping_v6_sendmsg static 2016-03-23 22:09:58 -04:00
pcmcia
ras
rdma Round two of 4.6 merge window patches 2016-03-22 15:48:44 -07:00
rxrpc
scsi
soc IOMMU Updates for Linux v4.6 2016-03-22 11:57:43 -07:00
sound
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-03-22 12:41:14 -07:00
trace Nothing major this round. Mostly small clean ups and fixes. 2016-03-24 10:52:25 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-03-23 23:25:14 -07:00
video
xen
Kbuild