From aa35dd6bdd033dea8aa3e20cbbbe10e06b2d044f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 31 Mar 2026 08:16:58 -0600 Subject: [PATCH] io_uring/bpf_filters: retain COW'ed settings on parse failures If io_parse_restrictions() fails, it ends up clearing any restrictions currently set. The intent is only to clear whatever it already applied, but it ends up clearing everything, including whatever settings may have been applied in a copy-on-write fashion already. Ensure that those are retained. Link: https://lore.kernel.org/io-uring/CAK8a0jzF-zaO5ZmdOrmfuxrhXuKg5m5+RDuO7tNvtj=kUYbW7Q@mail.gmail.com/ Reported-by: antonius Fixes: ed82f35b926b ("io_uring: allow registration of per-task restrictions") Signed-off-by: Jens Axboe --- io_uring/register.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/io_uring/register.c b/io_uring/register.c index 5f3eb018fb32..837324bf0223 100644 --- a/io_uring/register.c +++ b/io_uring/register.c @@ -178,9 +178,17 @@ static __cold int io_register_restrictions(struct io_ring_ctx *ctx, return -EBUSY; ret = io_parse_restrictions(arg, nr_args, &ctx->restrictions); - /* Reset all restrictions if an error happened */ + /* + * Reset all restrictions if an error happened, but retain any COW'ed + * settings. + */ if (ret < 0) { + struct io_bpf_filters *bpf = ctx->restrictions.bpf_filters; + bool cowed = ctx->restrictions.bpf_filters_cow; + memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); + ctx->restrictions.bpf_filters = bpf; + ctx->restrictions.bpf_filters_cow = cowed; return ret; } if (ctx->restrictions.op_registered) -- 2.47.3