[PATCH v2 net 00/12] sysctl: Fix data-races around ipv4_table.

From: Kuniyuki Iwashima
Date: Wed Jul 06 2022 - 19:40:59 EST


A sysctl variable is accessed concurrently, and there is always a chance
of data-race. So, all readers and writers need some basic protection to
avoid load/store-tearing.

The first half of this series changes some proc handlers used in ipv4_table
to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the
sysctl side. Then, the second half adds READ_ONCE() to the other readers
of ipv4_table.


Changes:
v2:
* Drop some changes that makes backporting difficult
* First cleanup patch
* Lockless helpers and .proc_handler changes
* Drop the tracing part for .sysctl_mem
* Steve already posted a fix
* Drop int-to-bool change for cipso
* Should be posted to net-next later
* Drop proc_dobool() change
* Can be included in another series

v1: https://lore.kernel.org/netdev/20220706052130.16368-1-kuniyu@xxxxxxxxxx/


Kuniyuki Iwashima (12):
sysctl: Fix data races in proc_dointvec().
sysctl: Fix data races in proc_douintvec().
sysctl: Fix data races in proc_dointvec_minmax().
sysctl: Fix data races in proc_douintvec_minmax().
sysctl: Fix data races in proc_doulongvec_minmax().
sysctl: Fix data races in proc_dointvec_jiffies().
tcp: Fix a data-race around sysctl_tcp_max_orphans.
inetpeer: Fix data-races around sysctl.
net: Fix data-races around sysctl_mem.
cipso: Fix data-races around sysctl.
icmp: Fix data-races around sysctl.
ipv4: Fix a data-race around sysctl_fib_sync_mem.

Documentation/networking/ip-sysctl.rst | 2 +-
include/net/sock.h | 2 +-
kernel/sysctl.c | 25 ++++++++++++++-----------
net/ipv4/cipso_ipv4.c | 12 +++++++-----
net/ipv4/fib_trie.c | 2 +-
net/ipv4/icmp.c | 5 +++--
net/ipv4/inetpeer.c | 12 ++++++++----
net/ipv4/tcp.c | 3 ++-
8 files changed, 37 insertions(+), 26 deletions(-)

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2.30.2