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 4CDA3563FCD for ; Fri, 11 Sep 2026 19:48:08 +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=1789156109; cv=none; b=iCjuFj1+B+FB48oU1owU7fnWtaj+MvWbJ1tO39F9k1pFeMIgIfCZWN+fhDUjCjv47qyrBunJf7aOTQAsEYbh6xuJKWDSX1JtDEx0IkGnGQIncSVzVlZyEn4UI/eGXAiZ2yEEMdFh6se+nqKDGjOQx+fnEZw/jgU0TGeWjEw4N3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156109; c=relaxed/simple; bh=6zdNyRl0W1yIK6gF3D1Qa+540tHl7MCFHJ9Ee9Kv6pk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=IjHvC6ltkaf0U10L+HIr6rJMcFu+sT4fcYMcBjl1c6K+u3bRq1vuaFS+a3yfSufibY1cYOTeq7h9O/cD3CryIayD1blbpzv6p83wPRHiWiLttGDiJxQeqdBqzJBHSfpOHYg3jfG9OF2oRy9GhQMOcebvInjWFFGSsRpcHRtr3Ss= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eANUtG8b; 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="eANUtG8b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78B561F0089A; Fri, 11 Sep 2026 19:48:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156088; bh=Qnl8RXGfjZW/b9UeBVpm4vOQdWgYgPrJ9WPBhY/ziik=; h=From:To:Cc:Subject:Date:Reply-To; b=eANUtG8bYnG6X2APBRKBxWLs2l0Okd+gObhrJtqomGnCXTNFboymhfQ9N9xhSD2lK bWlAapwE195DUJdPPTEECDYKvW5RnMfHczPAoLfP4f2Bhx2t7SOsuzkTgfJewhPCdB /u4yRlAvtfiMfFKupFpLadvjS5TS4g1vc6hePML0= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80983: net/smc: fix socket refcount leak in smc_switch_conns() Date: Fri, 11 Sep 2026 21:41:29 +0200 Message-ID: <2026091147-CVE-2026-80983-1ce7@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=3672; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=ahQyAGSgfueRBIHTEAKyW6A5K1dmAcRqDOPtVDoTqa0=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIu0n6H8MtXKyXRj75nF9wjV+ZQvJmW9T/aS/p83a1 LxP7rJARywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzk3luG+f5al5/qc31qYk9l amq0qDR0u5GnwjBX9rph1Kkj2olNnmvNpdJOZm9ON1cDAA== 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: net/smc: fix socket refcount leak in smc_switch_conns() smc_switch_conns() takes a reference on the SMC socket before dropping lgr->conns_lock, so the connection stays alive while the CDC slot is fetched: sock_hold(&smc->sk); read_unlock_bh(&lgr->conns_lock); /* pre-fetch buffer outside of send_lock, might sleep */ rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend); if (rc) goto err_out; The err_out label only drops the wr_tx link reference, so this early exit returns without the matching sock_put(). The second error exit is not affected, because sock_put() has already run by then. A leaked sk_refcnt means the smc_sock is never destroyed. Its send and receive buffers stay allocated, and for a user socket the reference held on the network namespace is never released, so the netns can no longer be torn down. smc_cdc_get_free_slot() fails when the target link goes down or when the connection has been killed while the switch is in progress. Both are reachable during the link failover this function implements, so the leak is triggered by the same hardware events that make smc_switch_conns() run in the first place. Restructure so there is a single sock_put() covering both outcomes, instead of adding a second one to the error path. The Linux kernel CVE team has assigned CVE-2026-80983 to this issue. Affected and fixed versions =========================== Issue introduced in 5.15 with commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a and fixed in 6.12.109 with commit 84dea0585f6b538ae895a8b1d025f4897737f3b1 Issue introduced in 5.15 with commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a and fixed in 6.18.50 with commit d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d Issue introduced in 5.15 with commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a and fixed in 7.2.4 with commit d9a879ac25958bdaecb669ce70e58f8e2ff170de Issue introduced in 5.15 with commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a and fixed in 7.3-rc1 with commit 719296c4aa8213d4ac8002e77d5956d436bc98d0 Issue introduced in 5.10.90 with commit 99f19566b1c4d3dc4d934ee2ef43faadebb56d70 Issue introduced in 5.14.14 with commit 0d9ddf515cde793841f738490037560fd6559c63 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-2026-80983 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/smc/smc_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/84dea0585f6b538ae895a8b1d025f4897737f3b1 https://git.kernel.org/stable/c/d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d https://git.kernel.org/stable/c/d9a879ac25958bdaecb669ce70e58f8e2ff170de https://git.kernel.org/stable/c/719296c4aa8213d4ac8002e77d5956d436bc98d0