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 DB76D3E92BB for ; Sat, 15 Aug 2026 12:29:10 +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=1786796952; cv=none; b=C16vSR/79UTODwCbUIFp398pGQwy9pu6k5F+7shOhzGGtQUX8/eDVtOmhkN1rn+zuOIJpPBsb0344QYk9hFMcAJtFwz8ML/8fuiy5AnhYjP55/Y2PjFkjMwBKrKkKr7Jo6w3uHVxLwOnoe7wv4kuraviNhpdKWI9qkpkz2rrwPk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786796952; c=relaxed/simple; bh=SCynQGAMAqMM5kQ5A/N7L2mf9d6GMgGZ5By55S/qtHU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nKlRfHdlhF5OBS0juMBN9ElS2C9g8rJD7BQHjNbAt/9Jtmt6XqbvhKjzdmth7rLOW+VrN4e0yanC3/0a9QhutszKsrzO8+SsyUhdm4N0o2KUePyFELudrcqQs/6xWo2EuKVBsP2oSz2E2VU2H+u5qkiwRdpuC8AQLl8pOD6Yecw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pxe4HT/w; 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="pxe4HT/w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 378861F000E9; Sat, 15 Aug 2026 12:29:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786796950; bh=udqzMHlPb7/unASWS1dzTuVB3brVgPTi+rnczN6szDU=; h=From:To:Cc:Subject:Date:Reply-To; b=pxe4HT/wHbZ5lZzuHJczRwApuqu62oD4TQpyrfCrfqeAqFh2Xbr8XCbnkbtCuMLKV F/sUkPvlgSlJBX3Rbq++qXk5I63SsbGguZDLs+DH/OThw2qY/jAk6ZAt4w6W3U5E7Z Bv8SASoQjZ/vF+BmOvoBGVHRcQO3Hvt1CVq6Uoo0= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-74479: net: pktgen: fix proc entry use-after-free Date: Sat, 15 Aug 2026 21:26:00 +0900 Message-ID: <2026081536-CVE-2026-74479-0cd6@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=3468; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=TcMHEuTnWGGIiCSMr2sFUwBzRAs0Tv08f5SAjaBFqjY=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNUQdcw+2qokzlJvzb9e9P3tU5517ufH6xQU1w+jmut cfz53ULd8SyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEzroyLFikHMLOFP3/+aQd R7WDzmxYwDCRvZ5hwYpblum6epPM0vfO2rR237MzNxWPGwAA 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: pktgen: fix proc entry use-after-free pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock. pktgen_remove_device() removes the same entry before _rem_dev_from_if_list() takes that lock. This allows the following interleaving: CPU 0 (NETDEV_CHANGENAME) CPU 1 (kpktgend) if_lock(t) proc_remove(pkt_dev->entry) proc_remove(pkt_dev->entry) pkt_dev->entry = proc_create_data(...) if_unlock(t) The kthread can pass the stale proc_dir_entry to proc_remove() after the rename path has freed it. A reproducer with a widened race window reports: BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80 Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67 Call Trace: proc_remove+0x78/0x80 pktgen_remove_device.isra.0+0x11c/0x4c0 pktgen_thread_worker+0x1214/0x6bc0 kthread+0x2c6/0x3b0 Allocated by task 95: __proc_create+0x204/0x790 proc_create_data+0x72/0xe0 pktgen_thread_write+0xd61/0x1510 Freed by task 28: kmem_cache_free+0xcb/0x3d0 proc_free_inode+0x5b/0x80 rcu_core+0x50a/0x1850 The buggy address belongs to the object at ffff8881478fea00 which belongs to the cache proc_dir_entry of size 192 Move proc_remove() into the if_lock-protected list removal helper. Keep it before list_del_rcu() to preserve the ordering required by add_device(). The rename path must then finish replacing the entry before removal, or it observes that the device is no longer on the list. The Linux kernel CVE team has assigned CVE-2026-74479 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.22 with commit 39df232f1a9ba48d41c68ee7d4046756e709cf91 and fixed in 6.18.44 with commit 4ef801b838d85c0ea5852c50667f7344ce3b6cd0 Issue introduced in 2.6.22 with commit 39df232f1a9ba48d41c68ee7d4046756e709cf91 and fixed in 7.1.8 with commit b006a5404470bd3eb2aa0425fc447183032047ef Issue introduced in 2.6.22 with commit 39df232f1a9ba48d41c68ee7d4046756e709cf91 and fixed in 7.2-rc6 with commit 817ff6efdb7f484ea547218e11e17d8e43daa3b4 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-2026-74479 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/core/pktgen.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/4ef801b838d85c0ea5852c50667f7344ce3b6cd0 https://git.kernel.org/stable/c/b006a5404470bd3eb2aa0425fc447183032047ef https://git.kernel.org/stable/c/817ff6efdb7f484ea547218e11e17d8e43daa3b4