From ebae0b2a6f4b3b949f30f076fbc65d3b0bb04785 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 26 Jun 2024 15:46:22 +0200 Subject: HID: bpf: fix dispatch_hid_bpf_device_event uninitialized ret value Looks like if a bpf program gets inserted and then removed, hdev->bpf.device_data is then allocated, but the loop iterating over the bpf program is never assigning ret. This is a problem and also revealed another bug in which only the last value of ret was checked. This effectively meant than only the last program in the chain could change the size of the incoming buffer. Reported-by: Dan Carpenter Link: https://lore.kernel.org/all/00f7b624-219f-4a05-a7ad-5335f15a41c7@moroto.mountain Fixes: 4a86220e046d ("HID: bpf: remove tracing HID-BPF capability") Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-1-cfd60fb6c79f@kernel.org Acked-by: Jiri Kosina Signed-off-by: Benjamin Tissoires --- drivers/hid/bpf/hid_bpf_dispatch.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index 06cc628e7bb4..b7b11a7c69db 100644 --- a/drivers/hid/bpf/hid_bpf_dispatch.c +++ b/drivers/hid/bpf/hid_bpf_dispatch.c @@ -57,11 +57,12 @@ dispatch_hid_bpf_device_event(struct hid_device *hdev, enum hid_report_type type } if (ret) - ctx_kern.ctx.retval = ret; + ctx_kern.ctx.size = ret; } } rcu_read_unlock(); + ret = ctx_kern.ctx.size; if (ret) { if (ret > ctx_kern.ctx.allocated_size) return ERR_PTR(-EINVAL); -- cgit v1.2.3