From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=51.250.56.165 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794568328; b=Z3uw48P2W74T6M/oKw1c0OOppY5sK8W+izqh2hvM57isuLHtXSQyEttutHIp3Cxcz8Mi 0ayZDiRGmPbFiNidjV2FmrPvr808Brb60H5uS7ApvP4GxPMHxAth1oiUJsAwXedkBUtdm 3a7mqR+K8HNTaeinspZuiqDLG8UZjylgBRM+c8wo7Fy8W3azO0xei20WV2yOp7v8pS88Q 8POSFrgC0qwqbjYcUMvxjlkoDw4rvG6a0I/9CQFnTCnMqnRLtIXdhJ3bBRituejUPtgRw 2PmlSlOZcMXkEC2MCJbQjwIVnZgrnCUYXeDdKjrpf0zi9zySGEyiJhxSaWl/ha1sr2Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794568328; h=DMARC-Filter:Received:Received:DKIM-Filter:DKIM-Signature:From:To:Cc: Subject:Date:Message-ID:X-Mailer:MIME-Version: Content-Transfer-Encoding; bh=Tdw0bwQZ8Q79OsNUucWIgUjlWSc89vsrssM2V4jSnNE=; b=BQyRjvNiEEUKmGY7x7KMuqomKuBAbEioaBQiJ6kGeQ4Y5atHWkTe4i2Ma+ueZ+NthnMp /vOumWx7j5f5S/ut5V7zVO/7arngYG4N3yQ7YL2YWj11aqinkAApN6c+YB1VLcxZQsKq5 kzls0I+pTNv44EW29hsx3gfcMjfK5fwlSprC7ptF8UsZVvhSWn9rVYLmcjBj10a3U9rD7 MyRTewF9qksuU2MafexfIH0JjS0+WTFElRmBssC6FUwfY2cGIPkd7RrwrQXrVfYeSY0YO ePmcL1dVJs6zCYxqbaasrm53/SBHLP20V46Odo4smmt7uvBaWMk5hi9qTunjps8nw9w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=ideco.ru; spf=pass smtp.mailfrom=ideco.ru; dkim=pass header.d=ideco.ru header.i=@ideco.ru header.a=rsa-sha256 header.s=ics header.b=gukuY0Xf; arc=none smtp.remote-ip=51.250.56.165 Received: from smtp.ideco.ru (smtp.ideco.ru [51.250.56.165]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA25C606A33B for ; Fri, 13 Nov 2026 11:12:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org EA25C606A33B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ideco.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideco.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ideco.ru header.i=@ideco.ru header.a=rsa-sha256 header.s=ics header.b=gukuY0Xf Received: from [169.254.254.254] (localhost [127.0.0.1]) by smtp.ideco.ru (Postfix) with ESMTP id 1D28226BC6; Fri, 13 Nov 2026 16:12:06 +0500 (+05) Received: from fedora (5cfcd9fa.dynamic.mv.ru [92.252.217.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp.ideco.ru (Postfix) with ESMTPSA id 7E90B26BC3; Fri, 13 Nov 2026 16:12:03 +0500 (+05) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.ideco.ru 7E90B26BC3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ideco.ru; s=ics; t=1794568324; bh=Tdw0bwQZ8Q79OsNUucWIgUjlWSc89vsrssM2V4jSnNE=; h=From:To:Cc:Subject:Date; b=gukuY0Xf1gE5F2BvUTIqm9aSWpFRbNUnT4Bv04r5npETypYaaeJsjkscsFGwjiLvB KmIilEUBW+ADZZJmAq4Z2ABzv1ZiShcJ81YL27mwVB+oGJF1bLqImpYYsKrwF75lBr AjwnK8TNMEWoRLHi2F6+BGb9sUu6q/MY2UefTCPpshCsMw2wnLKdrBdvhpgs8n8M7G SP6LXhN+unVyBEgmYDPEL+3tbYjKYQjKoQGrLJ7Ux+vva+E6UyegKkBjtRi0+g/jUL iqs3WPcypsurLJeq+RBD1CS3Ac9yXTfGbGHXVYqaEse1DfGtY/25VE49uFny6KUqMJ VxlUpkm1C4Pbw== From: Alex Kazinsky To: Daniel Thompson Cc: Alex Kazinsky , Douglas Anderson , Naveen Kumar Chaudhary , Greg Kroah-Hartman , Tim Bird , Martin Hicks , kgdb-bugreport@lists.sourceforge.net, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: [PATCH] kdb: Reject zero BYTESPERWORD before calculating the repeat count Date: Fri, 13 Nov 2026 15:11:51 +0400 Message-ID: <20261113111152.4190309-1-a.kazinsky@ideco.ru> X-Mailer: git-send-email 2.56.0 X-Mailing-List: linux-kernel@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 Setting BYTESPERWORD to zero in the kdb environment causes kdb_md() to divide by zero when calculating the initial repeat count. The existing width validation happens after this division. Reject a zero width with KDB_BADWIDTH before calculating the repeat count. Found by Linux Verification Center (linuxtesting.org) with SVACE static analysis tool. Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Alex Kazinsky --- kernel/debug/kdb/kdb_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 40c332d2179d..c3cbeb25f6fb 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1527,6 +1527,9 @@ static int kdb_md(int argc, const char **argv) kdbgetintenv("RADIX", &radix); kdbgetintenv("BYTESPERWORD", &bytesperword); + if (!bytesperword) + return KDB_BADWIDTH; + /* Assume 'md ' and start with environment values */ repeat = mdcount * 16 / bytesperword; -- 2.56.0