{ "cveId": "CVE-2026-23428", "url": "https://patchblox.com/security/cve/CVE-2026-23428", "summary": "CVE-2026-23428 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-23428, released April 3, 2026. It is not reported as exploited. Patch Radar priority: High.", "title": "ksmbd: fix use-after-free of share_conf in compound request", "description": "In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of share_conf in compound request smb2_get_ksmbd_tcon() reuses work-\u003Etcon in compound requests without validating tcon-\u003Et_state. ksmbd_tree_conn_lookup() checks t_state == TREE_CONNECTED on the initial lookup path, but the compound reuse path bypasses this check entirely. If a prior command in the compound (SMB2_TREE_DISCONNECT) sets t_state to TREE_DISCONNECTED and frees share_conf via ksmbd_share_config_put(), subsequent commands dereference the freed share_conf through work-\u003Etcon-\u003Eshare_conf. KASAN report: [ 4.144653] ================================================================== [ 4.145059] BUG: KASAN: slab-use-after-free in smb2_write\u002B0xc74/0xe70 [ 4.145415] Read of size 4 at addr ffff88810430c194 by task kworker/1:1/44 [ 4.145772] [ 4.145867] CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted 7.0.0-rc3\u002B #60 PREEMPTLAZY [ 4.145871] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX \u002B PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 4.145875] Workqueue: ksmbd-io handle_ksmbd_work [ 4.145888] Call Trace: [ 4.145892] \u003CTASK\u003E [ 4.145894] dump_stack_lvl\u002B0x64/0x80 [ 4.145910] print_report\u002B0xce/0x660 [ 4.145919] ? __pfx__raw_spin_lock_irqsave\u002B0x10/0x10 [ 4.145928] ? smb2_write\u002B0xc74/0xe70 [ 4.145931] kasan_report\u002B0xce/0x100 [ 4.145934] ? smb2_write\u002B0xc74/0xe70 [ 4.145937] smb2_write\u002B0xc74/0xe70 [ 4.145939] ? __pfx_smb2_write\u002B0x10/0x10 [ 4.145942] ? _raw_spin_unlock\u002B0xe/0x30 [ 4.145945] ? ksmbd_smb2_check_message\u002B0xeb2/0x24c0 [ 4.145948] ? smb2_tree_disconnect\u002B0x31c/0x480 [ 4.145951] handle_ksmbd_work\u002B0x40f/0x1080 [ 4.145953] process_one_work\u002B0x5fa/0xef0 [ 4.145962] ? assign_work\u002B0x122/0x3e0 [ 4.145964] worker_thread\u002B0x54b/0xf70 [ 4.145967] ? __pfx_worker_thread\u002B0x10/0x10 [ 4.145970] kthread\u002B0x346/0x470 [ 4.145976] ? recalc_sigpending\u002B0x19b/0x230 [ 4.145980] ? __pfx_kthread\u002B0x10/0x10 [ 4.145984] ret_from_fork\u002B0x4fb/0x6c0 [ 4.145992] ? __pfx_ret_from_fork\u002B0x10/0x10 [ 4.145995] ? __switch_to\u002B0x36c/0xbe0 [ 4.145999] ? __pfx_kthread\u002B0x10/0x10 [ 4.146003] ret_from_fork_asm\u002B0x1a/0x30 [ 4.146013] \u003C/TASK\u003E [ 4.146014] [ 4.149858] Allocated by task 44: [ 4.149953] kasan_save_stack\u002B0x33/0x60 [ 4.150061] kasan_save_track\u002B0x14/0x30 [ 4.150169] __kasan_kmalloc\u002B0x8f/0xa0 [ 4.150274] ksmbd_share_config_get\u002B0x1dd/0xdd0 [ 4.150401] ksmbd_tree_conn_connect\u002B0x7e/0x600 [ 4.150529] smb2_tree_connect\u002B0x2e6/0x1000 [ 4.150645] handle_ksmbd_work\u002B0x40f/0x1080 [ 4.150761] process_one_work\u002B0x5fa/0xef0 [ 4.150873] worker_thread\u002B0x54b/0xf70 [ 4.150978] kthread\u002B0x346/0x470 [ 4.151071] ret_from_fork\u002B0x4fb/0x6c0 [ 4.151176] ret_from_fork_asm\u002B0x1a/0x30 [ 4.151286] [ 4.151332] Freed by task 44: [ 4.151418] kasan_save_stack\u002B0x33/0x60 [ 4.151526] kasan_save_track\u002B0x14/0x30 [ 4.151634] kasan_save_free_info\u002B0x3b/0x60 [ 4.151751] __kasan_slab_free\u002B0x43/0x70 [ 4.151861] kfree\u002B0x1ca/0x430 [ 4.151952] __ksmbd_tree_conn_disconnect\u002B0xc8/0x190 [ 4.152088] smb2_tree_disconnect\u002B0x1cd/0x480 [ 4.152211] handle_ksmbd_work\u002B0x40f/0x1080 [ 4.152326] process_one_work\u002B0x5fa/0xef0 [ 4.152438] worker_thread\u002B0x54b/0xf70 [ 4.152545] kthread\u002B0x346/0x470 [ 4.152638] ret_from_fork\u002B0x4fb/0x6c0 [ 4.152743] ret_from_fork_asm\u002B0x1a/0x30 [ 4.152853] [ 4.152900] The buggy address belongs to the object at ffff88810430c180 [ 4.152900] which belongs to the cache kmalloc-96 of size 96 [ 4.153226] The buggy address is located 20 bytes inside of [ 4.153226] freed 96-byte region [ffff88810430c180, ffff88810430c1e0) [ 4.153549] [ 4.153596] The buggy address belongs to the physical page: [ 4.153750] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88810430ce80 pfn:0x10430c [ 4.154000] flags: 0x ---truncated---", "published": "2026-04-03T16:16:23Z", "severity": "Important", "cvss": 7.8, "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "epss": 0.00344, "epssPercentile": 0.28129, "priority": "High", "priorityTier": 3, "exploited": false, "vendorExploited": false, "disclosed": false, "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23428", "fixes": [ { "platform": "linux", "product": "linux", "release": "Debian 12.15 (bookworm)", "fixedVersion": "6.1.170-1", "fix": "DEBIAN-CVE-2026-23428", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-23428", "released": "2026-04-03T16:16:23Z" }, { "platform": "linux", "product": "linux", "release": "Debian 13.5 (trixie)", "fixedVersion": "6.12.85-1", "fix": "DEBIAN-CVE-2026-23428", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-23428", "released": "2026-04-03T16:16:23Z" }, { "platform": "linux", "product": "linux", "release": "Debian 14", "fixedVersion": "6.19.10-1", "fix": "DEBIAN-CVE-2026-23428", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-23428", "released": "2026-04-03T16:16:23Z" } ], "noFixYet": [], "dataAsOf": "2026-11-09T01:18:40Z", "attribution": { "text": "Data: Patchblox Patch Radar", "url": "https://patchblox.com/security/patch-radar", "terms": "https://patchblox.com/security/patch-radar/use-the-data" } }