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| author | Jens Axboe <axboe@kernel.dk> | 2019-10-30 08:42:56 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-10-30 08:42:56 -0600 |
| commit | 975c99a570967dd48e917dd7853867fee3febabd (patch) | |
| tree | d7888993bf41b642fee2f10cca0f9bf962e7c07d /fs/io_uring.c | |
| parent | 842f96124c5617b060cc0f071dcfb6ab24bdd042 (diff) | |
| download | lwn-975c99a570967dd48e917dd7853867fee3febabd.tar.gz lwn-975c99a570967dd48e917dd7853867fee3febabd.zip | |
io_uring: io_wq_create() returns an error pointer, not NULL
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>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 8e25c25c7309..72d260520c8f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3489,8 +3489,9 @@ 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; } |