From: Benjamin Tissoires Date: Wed, 26 Jun 2024 13:46:22 +0000 (+0200) Subject: HID: bpf: fix dispatch_hid_bpf_device_event uninitialized ret value X-Git-Tag: v6.11-rc1~148^2^2~24 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ebae0b2a6f4b3b949f30f076fbc65d3b0bb04785;p=thirdparty%2Flinux.git 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 --- diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index 06cc628e7bb45..b7b11a7c69db2 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);