ALSA: usb-audio: Use flexible allocation for FCP packets

Allocate FCP request and response packets with kmalloc_flex() for
the trailing packet data instead of passing the computed struct size
directly to kmalloc().

Keep the computed packet sizes for the USB transfer length checks.

Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260519004834.627676-1-rosenp@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/fcp.c b/sound/usb/fcp.c
index 0fc4d063c48a5890137d9ac1fc80eb1ce6237ea0..ea746bdb36ffcfc48b7ac08f69110463cc96ecb9 100644 (file)
--- a/sound/usb/fcp.c
+++ b/sound/usb/fcp.c
@@ -191,13 +191,13 @@ static int fcp_usb(struct usb_mixer_interface *mixer, u32 opcode,
 
        struct fcp_usb_packet *req __free(kfree) = NULL;
        size_t req_buf_size = struct_size(req, data, req_size);
-       req = kmalloc(req_buf_size, GFP_KERNEL);
+       req = kmalloc_flex(*req, data, req_size);
        if (!req)
                return -ENOMEM;
 
        struct fcp_usb_packet *resp __free(kfree) = NULL;
        size_t resp_buf_size = struct_size(resp, data, resp_size);
-       resp = kmalloc(resp_buf_size, GFP_KERNEL);
+       resp = kmalloc_flex(*resp, data, resp_size);
        if (!resp)
                return -ENOMEM;