[PATCH v2] HID: rate-limit hid_warn to prevent log flooding
From: Li Chen <hidden>
Date: 2025-06-20 02:15:17
Also in:
lkml
Subsystem:
hid core layer, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
From: Li Chen <redacted> Syzkaller can create many uhid devices that trigger repeated warnings like: "hid-generic xxxx: unknown main item tag 0x0" These messages can flood the system log, especially if a crash occurs (e.g., with a slow UART console, leading to soft lockups). To mitigate this, convert `hid_warn()` to use `dev_warn_ratelimited()`. This helps reduce log noise and improves system stability under fuzzing or faulty device scenarios. Signed-off-by: Li Chen <redacted> --- Changelog: v2: Introduce hid_warn_ratelimited to rate-limit the specified log. drivers/hid/hid-core.c | 2 +- include/linux/hid.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index b348d0464314c..aaba7164a8c9a 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c@@ -661,7 +661,7 @@ static int hid_parser_main(struct hid_parser *parser, struct hid_item *item) item->tag <= HID_MAIN_ITEM_TAG_RESERVED_MAX) hid_warn(parser->device, "reserved main item tag 0x%x\n", item->tag); else - hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag); + hid_warn_ratelimited(parser->device, "unknown main item tag 0x%x\n", item->tag); ret = 0; }
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 568a9d8c749bc..7f260e0e20498 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h@@ -1239,6 +1239,8 @@ void hid_quirks_exit(__u16 bus); dev_notice(&(hid)->dev, fmt, ##__VA_ARGS__) #define hid_warn(hid, fmt, ...) \ dev_warn(&(hid)->dev, fmt, ##__VA_ARGS__) +#define hid_warn_ratelimited(hid, fmt, ...) \ + dev_warn_ratelimited(&(hid)->dev, fmt, ##__VA_ARGS__) #define hid_info(hid, fmt, ...) \ dev_info(&(hid)->dev, fmt, ##__VA_ARGS__) #define hid_dbg(hid, fmt, ...) \
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2.49.0