PT-2026-64648 · Linux · Linux
CVE-2026-64427
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Published
2026-07-25
·
Updated
2026-07-25
None
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In the Linux kernel, the following vulnerability has been resolved:
HID: logitech-dj: Fix maxfield check in DJ short report validation
Commit b6a57912854e ("HID: logitech-dj: Prevent REPORT ID DJ SHORT
related user initiated OOB write") added validation for the DJ short
output report, but the error path dereferences rep->field[0] even when
rep->maxfield is zero.
Commit 8b9a097eb2fc ("HID: logitech-dj: fix wrong detection of bad
DJ SHORT output report") made the check conditional on rep being present,
but a crafted descriptor can still create report ID 0x20 with only padding
output items. hid-core registers the report, ignores the padding field,
and leaves rep->maxfield as zero.
In that case the validation enters the rep->maxfield < 1 branch and then
dereferences rep->field[0]->report count while printing the error message,
causing a NULL pointer dereference during probe. This is reproducible with
uhid by emulating a Logitech receiver with a padding-only DJ short output
report:
BUG: KASAN: null-ptr-deref in logi dj probe+0xb1/0x754 [hid logitech dj]
Read of size 4 at addr 0000000000000028 by task kworker/4:1/129
...
Call Trace:
logi dj probe+0xb1/0x754 [hid logitech dj]
hid device probe+0x329/0x3f0 [hid]
really probe+0x162/0x570
device attach+0x137/0x2c0
bus probe device+0x38/0xc0
device add+0xa56/0xce0
hid add device+0x19c/0x280 [hid]
uhid device add worker+0x2c/0xb0 [uhid]
Reject the zero-field report before printing the field report count.
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Related Identifiers
Affected Products
Linux