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=1793210201; b=dFYOL5u9IWsP9GQqMxm5gWMwGD9MlTXdMk8GrtPhEL9Bm+KQwV3+poY+XTYtqgl2SEem ZRrjhd+/uawjrj0uYxpjrsW70Oq32Z3HgkZSjVSYsh2P1OPJAF8sAdTtyDoAECaI2jnjw oC37RFPNS3vVOKlIRiDOH/Odg20iBuoB0U7CnIFpRUFI7l/Q2lALZTutnWMnNpk59EnlQ wa+tWA91IDdyVO7mzerZ7zptNsyPZvs0We7MJq3g3vFIA5W5Yh3H4hxuD/VsLNbKpoRgk diOz0q5rCVElhb/X359iLA7tFMYXCb31UFHIgJ5xdsn8v5mbPJlJg5yn1mv6CoDW7NQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210201; 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=q/rfqLkirPmOkKUUnft3OILsul5u8GL1d3fQF1wvp8o=; b=ANYYc05Ayro2Bslfpy3dji7W6d20NCXx0zkJgWMjU5ELdZESRXdvwDL/q1QOMTLrdZqT M96SmVGUqk5zfIxyJr/qb7Jq9VLbDvNGnWvXQZ+c8QvRclHHjOykF+ZpmJ+bxGL/BLYBz BC9KnpdbWSDpOSv1gcnxp812nvlhKEU/0e8CBG4JilWBaBChWRHWV74KzqAUzcrObLbDq MTjUVzv3ZWhxGGXAVzHEegRH2/O9rM6WO1Cp+9sSJ7pJL5IzeAhLz3j/9fQ8utYqMzRkl 3e3BuO8tASeA5anbYNlauvmkqy5fe89Dq//RE72NeLQw3gkLGsdBz9COToJOF10c9lg== 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=RBoVwfIF; 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 8CDCB606A32D; Wed, 28 Oct 2026 17:56:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=RBoVwfIF Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD82C1F01825; Wed, 28 Oct 2026 17:56:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210201; bh=q/rfqLkirPmOkKUUnft3OILsul5u8GL1d3fQF1wvp8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RBoVwfIFY9VCCIPBsTc0X3T7ul3BwJ7unuvThIAhoMF2zxozpT0DRFuOmNmvW7O6M sJdNT3y5eFpE5X73LFuu5UiMJbMTI2Icv/DF62KWV4V6lEbciLyChwteZzk1swLzzc VctG9MnF9vrDynX2MGDAtVynhdESV9CsKsaySLoc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Jose Fernandez (Anthropic)" , Ben Cressey , Mikulas Patocka , Sasha Levin Subject: [PATCH 6.6 113/168] dm-integrity: fix infinite loop on discard with large tag size Date: Wed, 28 Oct 2026 18:00:49 +0100 Message-ID: <20261028165945.762878814@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165943.089486480@linuxfoundation.org> References: <20261028165943.089486480@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Cressey [ Upstream commit 18d80c77b4c7dd20699e81cedfbbff4e9d198f28 ] When integrity_metadata handles a discard, it fills a buffer with DISCARD_FILLER and writes it over the tags, max_blocks blocks at a time. If the kmalloc fails, the buffer is the on-stack array checksums_onstack and max_size is set to HASH_MAX_DIGESTSIZE. So if the tag size is larger than HASH_MAX_DIGESTSIZE, max_blocks is zero, bi_size is never decremented and the loop never terminates. Fix this by using sizeof(checksums_onstack) as max_size. The array has MAX_TAG_SIZE bytes since commit b93b6643e9b5 ("dm integrity: fix a crash with unusually large tag size"), so max_blocks is at least 1. Fixes: 84597a44a9d8 ("dm integrity: add optional discard support") Cc: stable@vger.kernel.org Reviewed-by: Jose Fernandez (Anthropic) Signed-off-by: Ben Cressey Assisted-by: Claude:unspecified Signed-off-by: Mikulas Patocka [ sashal: Adjusted context for the absence of keyed-discard support. ] Signed-off-by: Sasha Levin --- drivers/md/dm-integrity.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index d66eb4e36811a..a10143b51c984 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1814,7 +1814,7 @@ static void integrity_metadata(struct work_struct *w) if (unlikely(dio->op == REQ_OP_DISCARD)) { unsigned int bi_size = dio->bio_details.bi_iter.bi_size; - unsigned int max_size = likely(checksums != checksums_onstack) ? PAGE_SIZE : HASH_MAX_DIGESTSIZE; + unsigned int max_size = likely(checksums != checksums_onstack) ? PAGE_SIZE : sizeof(checksums_onstack); unsigned int max_blocks = max_size / ic->tag_size; memset(checksums, DISCARD_FILLER, max_size); -- 2.53.0