From: Anas Iqbal Date: Tue, 31 Mar 2026 21:07:39 +0000 (+0100) Subject: io_uring: cast id to u64 before shifting in io_allocate_rbuf_ring() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=77d8c8d0f1b76a005267ee9714ed98964c87ecc5;p=thirdparty%2Fkernel%2Flinux.git io_uring: cast id to u64 before shifting in io_allocate_rbuf_ring() Smatch warns: io_uring/zcrx.c:393 io_allocate_rbuf_ring() warn: should 'id << 16' be a 64 bit type? The expression 'id << IORING_OFF_PBUF_SHIFT' is evaluated using 32-bit arithmetic because id is a u32. This may overflow before being promoted to the 64-bit mmap_offset. Cast id to u64 before shifting to ensure the shift is performed in 64-bit arithmetic. Signed-off-by: Anas Iqbal Signed-off-by: Pavel Begunkov Link: https://patch.msgid.link/52400e1b343691416bef3ed3ae287fb1a88d407f.1774780198.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 1ce867c68446b..b8f15439d5df6 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -384,7 +384,7 @@ static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx, return -EINVAL; mmap_offset = IORING_MAP_OFF_ZCRX_REGION; - mmap_offset += id << IORING_OFF_PBUF_SHIFT; + mmap_offset += (u64)id << IORING_OFF_PBUF_SHIFT; ret = io_create_region(ctx, &ifq->rq_region, rd, mmap_offset); if (ret < 0)