linux-kernel - Re: [syzbot] [io-uring?] KMSAN: uninit-value in io_req_task_work_add

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Message-ID: <tencent_B78F6EC46ED2CC9E67F9C6DCD2C6C66D0906@qq.com>
Date: Wed, 24 Jul 2024 19:13:21 +0800
From: Edward Adam Davis <eadavis@...com>
To: syzbot+82609b8937a4458106ca@...kaller.appspotmail.com
Cc: linux-kernel@...r.kernel.org,
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [io-uring?] KMSAN: uninit-value in io_req_task_work_add_remote

when alloc buffer for req, init mem to 0

#syz test: upstream 2c9b3512402e

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 8e6faa942a6f..a650db25c383 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -933,7 +933,7 @@ static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
 __cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx)
 	__must_hold(&ctx->uring_lock)
 {
-	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
+	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO;
 	void *reqs[IO_REQ_ALLOC_BATCH];
 	int ret;