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authorJens Axboe <axboe@kernel.dk>2019-04-08 10:51:01 -0600
committerJens Axboe <axboe@kernel.dk>2019-04-08 10:51:01 -0600
commit3ec482d15cb986bf08b923f9193eeddb3b9ca69f (patch)
tree4f3f31a7670b0f9e0c6aebf008aef8bd5430394e
parent704236672edacf353c362bab70c3d3eda7bb4a51 (diff)
downloadlinux-3ec482d15cb986bf08b923f9193eeddb3b9ca69f.tar.gz
io_uring: restrict IORING_SETUP_SQPOLL to root
This options spawns a kernel side thread that will poll for submissions
(and completions, if IORING_SETUP_IOPOLL is set). As this allows a user
to potentially use more cycles outside of the normal hierarchy,
restrict the use of this feature to root.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/io_uring.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 07d6ef195d05..89aa8412b5f5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2245,6 +2245,10 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
 		goto err;
 
 	if (ctx->flags & IORING_SETUP_SQPOLL) {
+		ret = -EPERM;
+		if (!capable(CAP_SYS_ADMIN))
+			goto err;
+
 		if (p->flags & IORING_SETUP_SQ_AFF) {
 			int cpu;