kernel/linux.git/drivers/hid/hid-core.c, branch linux-7.2.y

HID: core: fix number/pointer type confusion on long items

2026-08-27T12:35:26+00:00

commit 28abce951343fcec26e397610868efa4e1395c3f upstream. When fetch_item() is called by hid_scan_report() on an item with HID_ITEM_TAG_LONG, it stores a pointer to the item data in item->data.longdata instead of storing a value directly in item->data.{u8/u16/u32}. When item_udata() or item_sdata() encounters such an item, it incorrectly assumes that the item is in short format, and therefore returns the lower part of a kernel pointer reinterpreted as a number. When a HID device is connected whose descriptor contains a HID_GLOBAL_ITEM_TAG_REPORT_SIZE encoded in long format with size=4, this causes the lower half of a kernel pointer to be printed into dmesg as a number, like this: hid (null): invalid report_size 107953555 To fix it, let item_udata() and item_sdata() verify that the item is in short format. Note that this bug only affects hid_scan_report(), while the main parsing pass hid_parse_collections() will always bail out when encountering a long item. Sidenote: There are currently no users of data.longdata; maybe we should just remove any parsing of long-format descriptors as a follow-up. Fixes: 3dc8fc083dbf ("HID: Use hid_parser for pre-scanning the report descriptors") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman

HID: core: fix OOB read of field->usage in hid_set_field()

2026-08-27T12:35:25+00:00

commit a13cdb19fcb223ed41bdab3bab42b98dba87e90b upstream. hid_set_field() hands field->usage + offset to hid_dump_input() before the guard that bounds offset: hid_dump_input(field->report->device, field->usage + offset, value); if (offset >= field->report_count) { hid_err(...); return -1; } Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is allocated inline with the hid_field in hid_register_field() and holds field->maxusage entries, so an offset past it reads off the end of the kvzalloc()ed allocation and into a neighbouring object. Had the guard run first, offset < report_count <= maxusage would already have confined the pointer to the array. A caller supplies such an offset today. picolcd_fb_send_tile() validates only report->maxfield before issuing hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its offsets are fixed at 11..42 and are never checked against the bound field. When the device registers that field with fewer usages, the framebuffer deferred-io work drives the read on every tile. KASAN reports a 4-byte slab-out-of-bounds read in hid_dump_input() below hid_set_field(), and the same boot logs "offset (1) exceeds report_count (1)" from the guard that runs only afterwards. Move the hid_dump_input() call below the guard. Because field->maxusage >= field->report_count, the guard then establishes that field->usage + offset lies inside the array before it is dereferenced, for every caller and without changing behaviour on the valid path. Discovered by XBOW, triaged by Baul Lee Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman

HID: core: Fix OOB read in hid_get_report for numbered reports

2026-06-29T09:10:23+00:00

When a caller passes a size of 0 to hid_report_raw_event() for a numbered report, the function originally called hid_get_report() before performing any size validation. Inside hid_get_report(), if the report is numbered (report_enum->numbered is true), it unconditionally dereferences data[0] to extract the report ID. With a size of 0, this results in an out-of-bounds read or kernel panic. Fix this by moving the numbered report size validation check before the call to hid_get_report(), ensuring that size is at least 1 before dereferencing the data pointer. Fixes: 2c85c61d1332 ("HID: pass the buffer size to hid_report_raw_event") Signed-off-by: Lee Jones Signed-off-by: Jiri Kosina

HID: core: Fix size_t specifier in hid_report_raw_event()

2026-05-18T20:05:41+00:00

When building for 32-bit platforms, for which 'size_t' is 'unsigned int', there are warnings around using the incorrect format specifier to print bsize in hid_report_raw_event(): drivers/hid/hid-core.c:2054:29: error: format specifies type 'long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat] 2053 | hid_warn_ratelimited(hid, "Event data for report %d is incorrect (%d vs %ld)\n", | ~~~ | %zu 2054 | report->id, csize, bsize); | ^~~~~ drivers/hid/hid-core.c:2076:29: error: format specifies type 'long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat] 2075 | hid_warn_ratelimited(hid, "Event data for report %d was too short (%d vs %ld)\n", | ~~~ | %zu 2076 | report->id, rsize, bsize); | ^~~~~ Use the proper 'size_t' format specifier, '%zu', to clear up the warnings. Cc: stable@vger.kernel.org Fixes: 2c85c61d1332 ("HID: pass the buffer size to hid_report_raw_event") Reported-by: Miguel Ojeda Closes: https://lore.kernel.org/20260516020430.110135-1-ojeda@kernel.org/ Signed-off-by: Nathan Chancellor Signed-off-by: Linus Torvalds

HID: core: introduce hid_safe_input_report()

2026-05-12T16:03:58+00:00

hid_input_report() is used in too many places to have a commit that doesn't cross subsystem borders. Instead of changing the API, introduce a new one when things matters in the transport layers: - usbhid - i2chid This effectively revert to the old behavior for those two transport layers. Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina

HID: pass the buffer size to hid_report_raw_event

2026-05-12T16:03:37+00:00

commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") enforced the provided data to be at least the size of the declared buffer in the report descriptor to prevent a buffer overflow. However, we can try to be smarter by providing both the buffer size and the data size, meaning that hid_report_raw_event() can make better decision whether we should plaining reject the buffer (buffer overflow attempt) or if we can safely memset it to 0 and pass it to the rest of the stack. Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Tissoires Acked-by: Johan Hovold Reviewed-by: Greg Kroah-Hartman Signed-off-by: Jiri Kosina

Merge branch 'for-7.1/lenovo-v2' into for-linus

2026-04-16T19:07:13+00:00

- new driver for Lenovo Legion Go / S devices (Derek J. Clark)

HID: core: clamp report_size in s32ton() to avoid undefined shift

2026-04-13T09:39:31+00:00

s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does. Cc: stable Cc: Jiri Kosina Cc: Benjamin Tissoires Cc: linux-input@vger.kernel.org Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Jiri Kosina

HID: core: do not allow parsing 0-sized reports

2026-04-09T15:59:54+00:00

Commit d7db259bd6df ("HID: core: factor out hid_parse_collections()") reworked collection parsing code and inadvertently allowed returning "success" when parsing 0-sized reports where old code returned -EINVAL. Restore the original behavior by doing an explicit check. Note that the error message now differs from the generic "item fetching failed at offset %u/%u" that is now used only for non-empty descriptors. Fixes: d7db259bd6df ("HID: core: factor out hid_parse_collections()") Signed-off-by: Dmitry Torokhov Signed-off-by: Jiri Kosina

HID: core: use free(kfree) and free(kvfree) to clean up temporary buffers

2026-03-27T11:07:12+00:00

This simplifies error handling and protects against memory leaks. Signed-off-by: Dmitry Torokhov Signed-off-by: Jiri Kosina