| Message ID | 20190408081513.GB15239@kadam (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] cpumask: Introduce possible_cpu_safe() | expand |
The io_uring patches are slated for v5.7 so we should figure out a solution for this bug. regrds, dan carpenter
On Tue, Apr 30, 2019 at 12:26:19PM +0300, Dan Carpenter wrote: > The io_uring patches are slated for v5.7 so we should figure out a > solution for this bug. > Never mind. We merged a different fix. 975554b03edd ("io_uring: fix SQPOLL cpu validation"). regards, dan carpenter
diff --git a/fs/io_uring.c b/fs/io_uring.c index c0fecb9d889f..9789887b0d36 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2240,16 +2240,13 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx, ctx->sq_thread_idle = HZ; ret = -EINVAL; - if (!cpu_possible(p->sq_thread_cpu)) + if (!cpu_possible_safe(p->sq_thread_cpu)) goto err; if (ctx->flags & IORING_SETUP_SQPOLL) { if (p->flags & IORING_SETUP_SQ_AFF) { - int cpu; - - cpu = array_index_nospec(p->sq_thread_cpu, NR_CPUS); ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread, - ctx, cpu, + ctx, p->sq_thread_cpu, "io_uring-sq"); } else { ctx->sqo_thread = kthread_create(io_sq_thread, ctx,
The "p->sq_thread_cpu" variable is an integer which comes from the user. We can't pass values greater than NR_CPUS to cpu_possible() or it could lead to an out of bound read and possibly an Oops. The recently added cpu_possible_safe() function can handle unfiltered input so lets use that instead. This patch also removes the call to array_index_nospec() since that is handled in cpu_possible_safe(). Fixes: 6c271ce2f1d5 ("io_uring: add submission polling") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- No change. fs/io_uring.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)