[GIT PULL] i src/register: clean up ring state on failed resize mmap

[bohmiiidd]

src/register: clean up ring state on failed resize mmap

When io_uring_resize_rings() succeeds on the kernel side but the
subsequent mmap() fails (e.g. due to RLIMIT_AS), the old rings have
already been unmapped and the kernel has committed to the new layout.
This leaves ring->sq and ring->cq holding stale or error-encoded
pointers (e.g. ring_ptr = (void *)-ENOMEM).

Any subsequent call like io_uring_get_sqe() or io_uring_submit()
will crash with SIGSEGV, and a call to io_uring_queue_exit() will
pass those dangling pointers to munmap(), resulting in undefined
behaviour.

Fix this by zeroing ring->sq and ring->cq before calling
io_uring_queue_exit() in the error path, so the ring is fully and
safely destroyed instead of left in a partially corrupted state.

Fixes: #1574
Signed-off-by: Ahmed Abdelmoemen ahmedabdelmoumen05@gmail.com

❯ git request-pull axboe-tree/master https://github.com/bohmiiidd/liburing fix/register-resize-mmap-cleanup
The following changes since commit ce320c7:

test/bind-listen: ensure 'ts' is set before io_uring_wait_cqe_timeout() (2026-05-11 13:50:15 -0600)

are available in the Git repository at:

https://github.com/bohmiiidd/liburing fix/register-resize-mmap-cleanup

for you to fetch changes up to 79da9db:

src/register: clean up ring state on failed resize mmap (2026-05-14 14:31:44 +0100)

---

Ahmed Abdelmoemen (1):
src/register: clean up ring state on failed resize mmap

src/register.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

[axboe]

Would you mind just rebasing it? I don't have an issue with merge commits, but they should happen when it gets pulled, not as a backwards merge.

[bohmiiidd]

Updated, thanks

[bohmiiidd]

Are you not considering merging the patch?