github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-06 21:58:01 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

net/rds: do not fail init when CONFIG_SYSCTL=n

Browse Source 
With CONFIG_SYSCTL=n, register_net_sysctl() and register_net_sysctl_sz()
are inline stubs that return NULL.  rds_sysctl_init(),
rds_ib_sysctl_init() and rds_tcp_init_net() all treat that NULL as
-ENOMEM, so RDS refuses to initialize at all even though every tunable
has a sane compiled-in default.

When RDS is built in, that is worse than a missing feature: the failed
rds_init() destroys rds_wq, but the rds_rdma initcall still runs, and
when rds_ib_sysctl_init() fails the same way, the error path in
rds_ib_init() flushes the already freed workqueue:

  BUG: KASAN: slab-use-after-free in touch_wq_lockdep_map
  ...
   __flush_workqueue
   rds_ib_init
   rds_rdma_init
  ...
  Allocated by task 1:
   alloc_workqueue_noprof
   rds_threads_init
   rds_init
  ...
  Freed by task 0:
   kfree
   rcu_do_batch

Only treat the NULL return as a failure when sysctl support is actually
compiled in.  The exit paths need no change: unregister_net_sysctl_table()
is an empty stub with CONFIG_SYSCTL=n and already tolerates a NULL header
otherwise.

The underlying problem of built-in transports initializing after
rds_init() has failed is independent of sysctl and is addressed
separately.

Reported-by: kernel test robot <yi1.lai@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202610190310.9737b2e3-lkp@intel.com
Fixes: 3e5048495c ("RDS: sysctls")
Fixes: e6babe4cc4 ("RDS/IB: Stats and sysctls")
Fixes: c6a58ffed5 ("RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket")
Suggested-by: Joel Granados <joel.granados@kernel.org>
Signed-off-by: Allison Henderson <achender@kernel.org>
Reviewed-by: Joel Granados <joel.granados@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://patch.msgid.link/20261021195837.142802-2-achender@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Allison Henderson 2026-10-21 12:58:36 -07:00 committed by Paolo Abeni
parent a58b221496
commit fbea154a86
3 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/rds/ib_sysctl.c
View File

@ -114,7 +114,7 @@ void rds_ib_sysctl_exit(void)
int rds_ib_sysctl_init(void)
{
rds_ib_sysctl_hdr = register_net_sysctl(&init_net, "net/rds/ib", rds_ib_sysctl_table);
if (!rds_ib_sysctl_hdr)
if (!rds_ib_sysctl_hdr && IS_ENABLED(CONFIG_SYSCTL))
return -ENOMEM;
return 0;
}

2
net/rds/sysctl.c
View File

@ -103,7 +103,7 @@ int rds_sysctl_init(void)
rds_sysctl_reg_table =
register_net_sysctl(&init_net, "net/rds", rds_sysctl_rds_table);
if (!rds_sysctl_reg_table)
if (!rds_sysctl_reg_table && IS_ENABLED(CONFIG_SYSCTL))
return -ENOMEM;
return 0;
}

2
net/rds/tcp.c
View File

@ -637,7 +637,7 @@ static __net_init int rds_tcp_init_net(struct net *net)
tbl[RDS_TCP_RCVBUF].data = &rtn->rcvbuf_size;
rtn->rds_tcp_sysctl = register_net_sysctl_sz(net, "net/rds/tcp", tbl,
ARRAY_SIZE(rds_tcp_sysctl_table));
if (!rtn->rds_tcp_sysctl) {
if (!rtn->rds_tcp_sysctl && IS_ENABLED(CONFIG_SYSCTL)) {
pr_warn("could not register sysctl\n");
err = -ENOMEM;
goto fail;