[PATCH 5.10 96/98] io_uring: fix xa_alloc_cycle() error return value check

From: Sasha Levin
Date: Tue Aug 24 2021 - 13:14:25 EST


From: Jens Axboe <axboe@xxxxxxxxx>

[ upstream commit a30f895ad3239f45012e860d4f94c1a388b36d14 ]

We currently check for ret != 0 to indicate error, but '1' is a valid
return and just indicates that the allocation succeeded with a wrap.
Correct the check to be for < 0, like it was before the xarray
conversion.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 61cf93700fe6 ("io_uring: Convert personality_idr to XArray")
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/io_uring.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ed641dca7957..762eae2440b5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9601,11 +9601,12 @@ static int io_register_personality(struct io_ring_ctx *ctx)

ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)iod,
XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
- if (!ret)
- return id;
- put_cred(iod->creds);
- kfree(iod);
- return ret;
+ if (ret < 0) {
+ put_cred(iod->creds);
+ kfree(iod);
+ return ret;
+ }
+ return id;
}

static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
--
2.30.2