From: Jens Axboe <axboe@kernel.dk> mainline inclusion from mainline-5.5-rc1 commit 975c99a570967dd48e917dd7853867fee3febabd category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- syzbot reported an issue where we crash at setup time if failslab is used. The issue is that io_wq_create() returns an error pointer on failure, not NULL. Hence io_uring thought the io-wq was setup just fine, but in reality it's a garbage error pointer. Use IS_ERR() instead of a NULL check, and assign ret appropriately. Reported-by: syzbot+221cc24572a2fed23b6b@syzkaller.appspotmail.com Fixes: 561fb04a6a22 ("io_uring: replace workqueue usage with io-wq") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> --- fs/io_uring.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 3c76aa56dd7f..960690b3d7b1 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3488,8 +3488,9 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx, /* Do QD, or 4 * CPUS, whatever is smallest */ concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); ctx->io_wq = io_wq_create(concurrency, ctx->sqo_mm); - if (!ctx->io_wq) { - ret = -ENOMEM; + if (IS_ERR(ctx->io_wq)) { + ret = PTR_ERR(ctx->io_wq); + ctx->io_wq = NULL; goto err; } -- 2.25.1