{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-23427", "tracking": { "current_release_date": "2026-04-03T16:54:19.582524Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-23427", "initial_release_date": "2026-04-03T15:41:00.237668Z", "revision_history": [ { "date": "2026-04-03T15:41:00.237668Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| Products created (5).| Products connected (7).| References created (5)." }, { "date": "2026-04-03T15:41:06.629495Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-04-03T16:47:42.182200Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (5)." } ], "status": "interim", "version": "3" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:git/8df4bcdb0a4232192b2445256c39b787d58ef14d|fp->conn\nto the current connection when handling a DURABLE_REQ_V2 context with\nSMB2_FLAGS_REPLAY_OPERATION. ksmbd_lookup_fd_cguid() does not filter by\nfp->conn, so it returns file handles that are already actively connected.\nThe unconditional overwrite replaces fp->conn, and when the overwriting\nconnection is subsequently freed, __ksmbd_close_fd() dereferences the\nstale fp->conn via spin_lock(&fp->conn->llist_lock), causing a\nuse-after-free.\n\nKASAN report:\n\n[ 7.349357] ==================================================================\n[ 7.349607] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x75/0xe0\n[ 7.349811] Write of size 4 at addr ffff8881056ac18c by task kworker/1:2/108\n[ 7.350010]\n[ 7.350064] CPU: 1 UID: 0 PID: 108 Comm: kworker/1:2 Not tainted 7.0.0-rc3+ #58 PREEMPTLAZY\n[ 7.350068] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[ 7.350070] Workqueue: ksmbd-io handle_ksmbd_work\n[ 7.350083] Call Trace:\n[ 7.350087] \n[ 7.350087] dump_stack_lvl+0x64/0x80\n[ 7.350094] print_report+0xce/0x660\n[ 7.350100] ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n[ 7.350101] ? __pfx___mod_timer+0x10/0x10\n[ 7.350106] ? _raw_spin_lock+0x75/0xe0\n[ 7.350108] kasan_report+0xce/0x100\n[ 7.350109] ? _raw_spin_lock+0x75/0xe0\n[ 7.350114] kasan_check_range+0x105/0x1b0\n[ 7.350116] _raw_spin_lock+0x75/0xe0\n[ 7.350118] ? __pfx__raw_spin_lock+0x10/0x10\n[ 7.350119] ? __call_rcu_common.constprop.0+0x25e/0x780\n[ 7.350125] ? close_id_del_oplock+0x2cc/0x4e0\n[ 7.350128] __ksmbd_close_fd+0x27f/0xaf0\n[ 7.350131] ksmbd_close_fd+0x135/0x1b0\n[ 7.350133] smb2_close+0xb19/0x15b0\n[ 7.350142] ? __pfx_smb2_close+0x10/0x10\n[ 7.350143] ? xas_load+0x18/0x270\n[ 7.350146] ? _raw_spin_lock+0x84/0xe0\n[ 7.350148] ? __pfx__raw_spin_lock+0x10/0x10\n[ 7.350150] ? _raw_spin_unlock+0xe/0x30\n[ 7.350151] ? ksmbd_smb2_check_message+0xeb2/0x24c0\n[ 7.350153] ? ksmbd_tree_conn_lookup+0xcd/0xf0\n[ 7.350154] handle_ksmbd_work+0x40f/0x1080\n[ 7.350156] process_one_work+0x5fa/0xef0\n[ 7.350162] ? assign_work+0x122/0x3e0\n[ 7.350163] worker_thread+0x54b/0xf70\n[ 7.350165] ? __pfx_worker_thread+0x10/0x10\n[ 7.350166] kthread+0x346/0x470\n[ 7.350170] ? recalc_sigpending+0x19b/0x230\n[ 7.350176] ? __pfx_kthread+0x10/0x10\n[ 7.350178] ret_from_fork+0x4fb/0x6c0\n[ 7.350183] ? __pfx_ret_from_fork+0x10/0x10\n[ 7.350185] ? __switch_to+0x36c/0xbe0\n[ 7.350188] ? __pfx_kthread+0x10/0x10\n[ 7.350190] ret_from_fork_asm+0x1a/0x30\n[ 7.350197] \n[ 7.350197]\n[ 7.355160] Allocated by task 123:\n[ 7.355261] kasan_save_stack+0x33/0x60\n[ 7.355373] kasan_save_track+0x14/0x30\n[ 7.355484] __kasan_kmalloc+0x8f/0xa0\n[ 7.355593] ksmbd_conn_alloc+0x44/0x6d0\n[ 7.355711] ksmbd_kthread_fn+0x243/0xd70\n[ 7.355839] kthread+0x346/0x470\n[ 7.355942] ret_from_fork+0x4fb/0x6c0\n[ 7.356051] ret_from_fork_asm+0x1a/0x30\n[ 7.356164]\n[ 7.356214] Freed by task 134:\n[ 7.356305] kasan_save_stack+0x33/0x60\n[ 7.356416] kasan_save_track+0x14/0x30\n[ 7.356527] kasan_save_free_info+0x3b/0x60\n[ 7.356646] __kasan_slab_free+0x43/0x70\n[ 7.356761] kfree+0x1ca/0x430\n[ 7.356862] ksmbd_tcp_disconnect+0x59/0xe0\n[ 7.356993] ksmbd_conn_handler_loop+0x77e/0xd40\n[ 7.357138] kthread+0x346/0x470\n[ 7.357240] ret_from_fork+0x4fb/0x6c0\n[ 7.357350] ret_from_fork_asm+0x1a/0x30\n[ 7.357463]\n[ 7.357513] The buggy address belongs to the object at ffff8881056ac000\n[ 7.357513] which belongs to the cache kmalloc-1k of size 1024\n[ 7.357857] The buggy address is located 396 bytes inside of\n[ 7.357857] freed 1024-byte region \n---truncated---", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23427.json" }, { "category": "description", "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in durable v2 replay of active file handles\n\nparse_durable_handle_context() unconditionally assigns dh_info->fp->conn\nto the current connection when handling a DURABLE_REQ_V2 context with\nSMB2_FLAGS_REPLAY_OPERATION. ksmbd_lookup_fd_cguid() does not filter by\nfp->conn, so it returns file handles that are already actively connected.\nThe unconditional overwrite replaces fp->conn, and when the overwriting\nconnection is subsequently freed, __ksmbd_close_fd() dereferences the\nstale fp->conn via spin_lock(&fp->conn->llist_lock), causing a\nuse-after-free.\n\nKASAN report:\n\n[ 7.349357] ==================================================================\n[ 7.349607] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x75/0xe0\n[ 7.349811] Write of size 4 at addr ffff8881056ac18c by task kworker/1:2/108\n[ 7.350010]\n[ 7.350064] CPU: 1 UID: 0 PID: 108 Comm: kworker/1:2 Not tainted 7.0.0-rc3+ #58 PREEMPTLAZY\n[ 7.350068] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[ 7.350070] Workqueue: ksmbd-io handle_ksmbd_work\n[ 7.350083] Call Trace:\n[ 7.350087] \n[ 7.350087] dump_stack_lvl+0x64/0x80\n[ 7.350094] print_report+0xce/0x660\n[ 7.350100] ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n[ 7.350101] ? __pfx___mod_timer+0x10/0x10\n[ 7.350106] ? _raw_spin_lock+0x75/0xe0\n[ 7.350108] kasan_report+0xce/0x100\n[ 7.350109] ? _raw_spin_lock+0x75/0xe0\n[ 7.350114] kasan_check_range+0x105/0x1b0\n[ 7.350116] _raw_spin_lock+0x75/0xe0\n[ 7.350118] ? __pfx__raw_spin_lock+0x10/0x10\n[ 7.350119] ? __call_rcu_common.constprop.0+0x25e/0x780\n[ 7.350125] ? close_id_del_oplock+0x2cc/0x4e0\n[ 7.350128] __ksmbd_close_fd+0x27f/0xaf0\n[ 7.350131] ksmbd_close_fd+0x135/0x1b0\n[ 7.350133] smb2_close+0xb19/0x15b0\n[ 7.350142] ? __pfx_smb2_close+0x10/0x10\n[ 7.350143] ? xas_load+0x18/0x270\n[ 7.350146] ? _raw_spin_lock+0x84/0xe0\n[ 7.350148] ? __pfx__raw_spin_lock+0x10/0x10\n[ 7.350150] ? _raw_spin_unlock+0xe/0x30\n[ 7.350151] ? ksmbd_smb2_check_message+0xeb2/0x24c0\n[ 7.350153] ? ksmbd_tree_conn_lookup+0xcd/0xf0\n[ 7.350154] handle_ksmbd_work+0x40f/0x1080\n[ 7.350156] process_one_work+0x5fa/0xef0\n[ 7.350162] ? assign_work+0x122/0x3e0\n[ 7.350163] worker_thread+0x54b/0xf70\n[ 7.350165] ? __pfx_worker_thread+0x10/0x10\n[ 7.350166] kthread+0x346/0x470\n[ 7.350170] ? recalc_sigpending+0x19b/0x230\n[ 7.350176] ? __pfx_kthread+0x10/0x10\n[ 7.350178] ret_from_fork+0x4fb/0x6c0\n[ 7.350183] ? __pfx_ret_from_fork+0x10/0x10\n[ 7.350185] ? __switch_to+0x36c/0xbe0\n[ 7.350188] ? __pfx_kthread+0x10/0x10\n[ 7.350190] ret_from_fork_asm+0x1a/0x30\n[ 7.350197] \n[ 7.350197]\n[ 7.355160] Allocated by task 123:\n[ 7.355261] kasan_save_stack+0x33/0x60\n[ 7.355373] kasan_save_track+0x14/0x30\n[ 7.355484] __kasan_kmalloc+0x8f/0xa0\n[ 7.355593] ksmbd_conn_alloc+0x44/0x6d0\n[ 7.355711] ksmbd_kthread_fn+0x243/0xd70\n[ 7.355839] kthread+0x346/0x470\n[ 7.355942] ret_from_fork+0x4fb/0x6c0\n[ 7.356051] ret_from_fork_asm+0x1a/0x30\n[ 7.356164]\n[ 7.356214] Freed by task 134:\n[ 7.356305] kasan_save_stack+0x33/0x60\n[ 7.356416] kasan_save_track+0x14/0x30\n[ 7.356527] kasan_save_free_info+0x3b/0x60\n[ 7.356646] __kasan_slab_free+0x43/0x70\n[ 7.356761] kfree+0x1ca/0x430\n[ 7.356862] ksmbd_tcp_disconnect+0x59/0xe0\n[ 7.356993] ksmbd_conn_handler_loop+0x77e/0xd40\n[ 7.357138] kthread+0x346/0x470\n[ 7.357240] ret_from_fork+0x4fb/0x6c0\n[ 7.357350] ret_from_fork_asm+0x1a/0x30\n[ 7.357463]\n[ 7.357513] The buggy address belongs to the object at ffff8881056ac000\n[ 7.357513] which belongs to the cache kmalloc-1k of size 1024\n[ 7.357857] The buggy address is located 396 bytes inside of\n[ 7.357857] freed 1024-byte region \n---truncated---", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23427" }, { "category": "other", "text": "4.1", "title": "NCSC Score" }, { "category": "other", "text": "The value of the most recent CVSS (V3) score, Is related to a product by vendor Linux", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-1286675", "CSAFPID-5992450", "CSAFPID-5992451", "CSAFPID-5992452", "CSAFPID-5992453", "CSAFPID-5992454" ], "known_not_affected": [ "CSAFPID-1286676", "CSAFPID-5904647", "CSAFPID-5904671", "CSAFPID-5905005", "CSAFPID-5905006", "CSAFPID-5905027" ] }, "references": [ { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23427.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23427" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/b0158d9d6f4ec5941e49a0b812735db2844f9975" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/568a25fd7bcdfb2790f7d42aa2a440dca4435c96" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/a5828c14a9e3d5eeed0bcc0a58f0f3fbca0cdcb2" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/9b0792c3eacf01e67f356d6ef9707b0ae5022419" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://git.kernel.org/stable/c/b425e4d0eb321a1116ddbf39636333181675d8f4" } ], "title": "CVE-2026-23427" } ] }