diff options
| author |   Paul E. McKenney <paulmck@kernel.org> | 2020-09-10 11:54:42 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-11-19 19:37:17 -0800 |
| commit | 50edb988534c621a56ca103c0c16ac59e7399f01 (patch) | |
| tree | f923f4e709fdfeb57409ea54367190a79649e4a4 /kernel/rcu | |
| parent | rcu/tree: Defer kvfree_rcu() allocation to a clean context (diff) | |
| download | linux-dev-50edb988534c621a56ca103c0c16ac59e7399f01.tar.xz linux-dev-50edb988534c621a56ca103c0c16ac59e7399f01.zip | |
srcu: Take early exit on memory-allocation failure
It turns out that init_srcu_struct() can be invoked from usermode tasks,
and that fatal signals received by these tasks can cause memory-allocation
failures. These failures are not handled well by init_srcu_struct(),
so much so that NULL pointer dereferences can result. This commit
therefore causes init_srcu_struct() to take an early exit upon detection
of memory-allocation failure.
Link: https://lore.kernel.org/lkml/20200908144306.33355-1-aik@ozlabs.ru/
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/srcutree.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index c13348ee80a5..6f7880acfdd5 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -177,11 +177,13 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) INIT_DELAYED_WORK(&ssp->work, process_srcu); if (!is_static) ssp->sda = alloc_percpu(struct srcu_data); + if (!ssp->sda) + return -ENOMEM; init_srcu_struct_nodes(ssp, is_static); ssp->srcu_gp_seq_needed_exp = 0; ssp->srcu_last_gp_end = ktime_get_mono_fast_ns(); smp_store_release(&ssp->srcu_gp_seq_needed, 0); /* Init done. */ - return ssp->sda ? 0 : -ENOMEM; + return 0; } #ifdef CONFIG_DEBUG_LOCK_ALLOC |