From f779ac0b8784858c3700f6660d606f436c62157a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 18 Nov 2025 19:30:45 -0700 Subject: [PATCH] io_uring/register: use correct location for io_rings_layout A previous consolidated the ring size etc calculations into io_prepare_config(), but missed updating io_register_resize_rings() correctly to use the calculated values. As a result, it ended up using on-stack uninitialized values, and hence either failed validating the size correctly, or just failed resizing because the sizes were random. This caused failures in the liburing regression tests: [...] Running test resize-rings.t resize=-7 test_basic 3000 failed Test resize-rings.t failed with ret 1 Running test resize-rings.t /dev/sda resize=-7 test_basic 3000 failed Test resize-rings.t failed with ret 1 Running test resize-rings.t /dev/nvme1n1 resize=-7 test_basic 3000 failed Test resize-rings.t failed with ret 1 Running test resize-rings.t /dev/dm-0 resize=-7 test_basic 3000 failed Test resize-rings.t failed with ret 1 because io_create_region() would return -E2BIG because of unintialized reg->size values. Adjust the struct io_rings_layout rl pointer to point to the correct location, and remove the (now dead) __rl on stack struct. Fixes: eb76ff6a6829 ("io_uring: pre-calculate scq layout") Signed-off-by: Jens Axboe --- io_uring/register.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/io_uring/register.c b/io_uring/register.c index fc66a53644835..db42f98562c4e 100644 --- a/io_uring/register.c +++ b/io_uring/register.c @@ -403,7 +403,7 @@ static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; unsigned i, tail, old_head; struct io_uring_params *p = &config.p; - struct io_rings_layout __rl, *rl = &__rl; + struct io_rings_layout *rl = &config.layout; int ret; memset(&config, 0, sizeof(config)); -- 2.47.3