From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794061777; b=a33ULI3K6MD/i1Ah9jQAqBON+OnwnsDGiB/+5Npd6s9LAR7PfAMkOO2J3ZJYQ2WK3lWl RRacPPjEtbWL5EFP6Et4Z75m+Xs7XmOSUXZqCzr0X7o5NCMFpj4vGGdAJsO50qiOvxtFS ghWJhl0Qnw19fenHZfTAqtOEB4+H5qm2IjQghujRLmF+TlQZzjmCB98VO4OSoBJdCSVhH y4xsUV6PNhra25WfvgkQK9KmOfHbBz992rsbgydKSIomyvsyRWzvmqhnSlY890MdtiNGN p/1SZU/CzWx8jHng6T1CEHpSdtI6KDThF8U/PVboBI6/ncr1j0q0RtRqJGU/I/rLzcQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061777; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=2fNa5ht33rCQpTj5WQn53c43AstS2rNvcSX6U6SSl1c=; b=rcnLJN8kbl/gQNjNKyBMbzFS9iOGRCaSmiN4IC2KiQnTNZSADA8gFd3lferPaMyP954Q 0KrvDUbTscViOvtBs0sn677Qg4bwsh4oKr3Fj0+feVJQZnaxCT657rNul9ajbKHInlID7 0KnFVM6w6BUa5rwo9J2xYjHdSDxQwL60W8HlFU3Uj/7BDOaWtnnTW2RljG+qLo2bCDJ00 CT13TLuqQ48MA/N7RJmUJG9SpjP9kD1mMUt+mNzcJvyuFcDHgQ3RDX0HXC2x+O++R9P+A dxZdIXVYB86ieVS32Z1vkT4fWizrqQyRI5tuoft8dC7N9XDdH1aHwDYG7kgjCvpjy6A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Lf+F0DMK; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C63EA606A326; Sat, 7 Nov 2026 14:29:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Lf+F0DMK Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EF561F0089F; Sat, 7 Nov 2026 14:29:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061776; bh=2fNa5ht33rCQpTj5WQn53c43AstS2rNvcSX6U6SSl1c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Lf+F0DMKDaJYaS+wHXvQ5OIaGU1YbjmfLMigZ95qYfsd8CC+BkHLW0lVtesGgarhv Vh+UuijTfEYcg0izthhAhmGdZ+PtSK3ERk9KpeQUdPLS6XpBS1/IcXdivg9u2Mi4I9 AGdaUFFDBkT7pNLevoXKiECBJghILBrO8xQLz0do= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alan Stern , syzbot+25a1d2907885b2182275@syzkaller.appspotmail.com, Benjamin Tissoires Subject: [PATCH 6.12 0809/1536] HID: core: Fix out-of-bounds left shift by 32 in s32ton() Date: Sat, 7 Nov 2026 08:47:05 -0500 Message-ID: <20261107135020.266196779@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit 5fe63b415c636c7f4f6848a8e53bdd4bbf0c300d upstream. Syzbot reported an out-of-bounds shift (32-bit integer shifted left by 32) in the s32ton() routine in the HID core. This routine converts a signed 32-bit integer to a signed n-bit integer, and it caps the value of n at 32. But when n == 32 there's no need to do anything; it can simply return the input value. This will avoid calculating (1 << n) when n is 32, which was the cause of the invalid shift. Signed-off-by: Alan Stern Fixes: 69c02ffde6ed ("HID: core: clamp report_size in s32ton() to avoid undefined shift") Reported-by: syzbot+25a1d2907885b2182275@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/6ac9cbd8.a150a118.27e199.0025.GAE@google.com/ Tested-by: syzbot+25a1d2907885b2182275@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Link: https://patch.msgid.link/dfa0aa1c-e55e-4316-8307-f72a07383634@rowland.harvard.edu Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -71,8 +71,8 @@ static u32 s32ton(__s32 value, unsigned if (!value || !n) return 0; - if (n > 32) - n = 32; + if (n >= 32) + return (u32) value; a = value >> (n - 1); if (a && a != -1)