Sometimes io_get_req will return a NUL, then we need to do the
correct error handling, otherwise it will cause the kernel null
pointer exception.
Fixes: 4fe2c963154c ("io_uring: add support for link with drain")
Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
---
fs/io_uring.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1621243..efc3c05 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2364,12 +2364,15 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes,
if (link && (sqes[i].sqe->flags & IOSQE_IO_DRAIN)) {
if (!shadow_req) {
shadow_req = io_get_req(ctx, NULL);
+ if (unlikely(!shadow_req))
+ goto out;
shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN);
refcount_dec(&shadow_req->refs);
}
shadow_req->sequence = sqes[i].sequence;
}
+out:
if (unlikely(mm_fault)) {
io_cqring_add_event(ctx, sqes[i].sqe->user_data,
-EFAULT);
@@ -2551,12 +2554,15 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit,
if (link && (s.sqe->flags & IOSQE_IO_DRAIN)) {
if (!shadow_req) {
shadow_req = io_get_req(ctx, NULL);
+ if (unlikely(!shadow_req))
+ goto out;
shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN);
refcount_dec(&shadow_req->refs);
}
shadow_req->sequence = s.sequence;
}
+out:
s.has_user = true;
s.needs_lock = false;
s.needs_fixed_file = false;
--
2.7.4
