From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15363372ED5 for ; Sat, 15 Aug 2026 06:23:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786775032; cv=none; b=TIEgSA95QkDRTDwnYlaffp1zANjmq42KkoLMKEpvV7RO+jtyNSW0kOJwfkLTgQFzTAvqDY0ECiRlIwth9mSL54PTohnhgkjKV9co2V8kaDJlEec+x2hZQa63Pgh/wlf9YG+GKUkjS57lVzIAvmzM4I8dqY1ljLWHXOwBTcAyqKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786775032; c=relaxed/simple; bh=ptyx5zNTQFapjO9XpIjiwznMtjsz67YjNstIzOFtBtc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=j/eX2KKMYEDW+VvIpL5mn4xGkVBIwfyLSngQKs3XU52NsKdfR2YuKXe6O7oQw1kxsBUF7drDojHtqWkUiEWeMOwqz5DvflxyAVDiOC03isP6reUTmnLFy/PvmYglnCIUo3XEKhqsG0Z5EUwTvp2HASQUAXigiPe4p7Lz6SBsAu0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CL8eSoj3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CL8eSoj3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6812B1F000E9; Sat, 15 Aug 2026 06:23:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786775031; bh=M4ykmfGz1n3IQCgt00+Knlhr2uUMX0rCLqVQlNhNJ1Y=; h=From:To:Cc:Subject:Date:Reply-To; b=CL8eSoj3L7y9HPNh5JvSL+LqhQ6IpoiFEs69McqcO+brHoaExHNFiuAuJ9KBZ1/mm 57PIdmoQL9iPdPHULindjAdMUo31fyqI5RkPRypvnaLWeHpiZKJ1vJHziV7OXyou61 d7lJJm+2yRWnOwfQJ5thELBrswCN/H51VIXEc4bs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-72333: Bluetooth: L2CAP: fix tx ident leak for commands without a response Date: Sat, 15 Aug 2026 15:06:52 +0900 Message-ID: <2026081508-CVE-2026-72333-b41d@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4087; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Mt36JVRzqnpLTOWupdy7//adgiQvHaCF8E0ur4ssSBs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNDA8mrGMJ3uX580+hUKdI8dZoC5nDUpXL9AsjTQvZ7 871+2bZEcvCIMjEICumyPJlG8/R/RWHFL0MbU/DzGFlAhnCwMUpABPpesgwz6jXNFw3Y/tLlx+m Vn9Fui64pzXPYpinY7w8126Zc2LbPv9zW9y0ru2P/pYNAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix tx ident leak for commands without a response Commit 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") changed ident allocation to use an IDA, releasing idents in l2cap_put_ident() when the matching response command is received. But identifiers allocated for commands that have no response defined are never released. In particular L2CAP_LE_CREDITS is sent repeatedly for the lifetime of an LE CoC channel, so a peer streaming data to the host exhausts the 1-255 ident range after 254 credit packets. From then on l2cap_get_ident() fails: kernel: Bluetooth: Unable to allocate ident: -28 and every subsequent L2CAP_LE_CREDITS packet is sent with ident 0, which is invalid (Core Spec, Vol 3, Part A, Section 4: "Signaling identifier 0x00 is an invalid identifier and shall never be used in any command"). Remote stacks that validate the ident drop these commands, never receive new credits, and the channel stalls permanently. With default socket buffers this happens after roughly 0.5 MB of received data (the exact amount depends on the socket receive buffer): < ACL Data TX: Handle 2048 flags 0x00 dlen 12 LE L2CAP: LE Flow Control Credit (0x16) ident 0 len 4 Source CID: 64 Credits: 1 Release the ident immediately after sending L2CAP_LE_CREDITS since no response will ever release it. Use a local variable instead of chan->ident so that an ident that an EXT_FLOWCTL channel may be waiting on (e.g. a pending reconfigure) is not overwritten by a credit packet. Also add the missing L2CAP_LE_CONN_RSP case to l2cap_put_ident() so idents allocated for outgoing L2CAP_LE_CONN_REQ commands are released when the response arrives. The Linux kernel CVE team has assigned CVE-2026-72333 to this issue. Affected and fixed versions =========================== Issue introduced in 6.18.21 with commit ea6cf86167b3972caa68972d2a1ad43ecbbb8331 and fixed in 6.18.40 with commit 0c602cb8f148a36bfb39c25ade400bdadc023c4f Issue introduced in 7.0 with commit 6c3ea155e5ee3e56606233acde8309afda66d483 and fixed in 7.1.5 with commit d0a2b0c81f112540a337cde1c20251bf05ddf1da Issue introduced in 7.0 with commit 6c3ea155e5ee3e56606233acde8309afda66d483 and fixed in 7.2-rc3 with commit 6e1930ece855a4c256f1c7e6632d634cfb9888b5 Issue introduced in 5.10.261 with commit ed97bb2cf96684ee646be6f37e4c4835f9d30caa Issue introduced in 5.15.212 with commit 84bc3197f7d87c5b89c156e853d0561a9154eceb Issue introduced in 6.19.11 with commit 8c1cdbc1bacc0cf9c27c3ebda11a81c3dcd01630 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-72333 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/bluetooth/l2cap_core.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/b8a32a5fc915b024c60f18d51b6cffd2bd64d4a6 https://git.kernel.org/stable/c/bd1e01170341291292fd4c46b5f6949da282ca6c https://git.kernel.org/stable/c/0c602cb8f148a36bfb39c25ade400bdadc023c4f https://git.kernel.org/stable/c/d0a2b0c81f112540a337cde1c20251bf05ddf1da https://git.kernel.org/stable/c/6e1930ece855a4c256f1c7e6632d634cfb9888b5