CVE-2026-23427 (GCVE-0-2026-23427)
Vulnerability from cvelistv5
Published
2026-04-03 15:15
Modified
2026-04-27 14:02
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in durable v2 replay of active file handles
parse_durable_handle_context() unconditionally assigns dh_info->fp->conn
to the current connection when handling a DURABLE_REQ_V2 context with
SMB2_FLAGS_REPLAY_OPERATION. ksmbd_lookup_fd_cguid() does not filter by
fp->conn, so it returns file handles that are already actively connected.
The unconditional overwrite replaces fp->conn, and when the overwriting
connection is subsequently freed, __ksmbd_close_fd() dereferences the
stale fp->conn via spin_lock(&fp->conn->llist_lock), causing a
use-after-free.
KASAN report:
[ 7.349357] ==================================================================
[ 7.349607] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x75/0xe0
[ 7.349811] Write of size 4 at addr ffff8881056ac18c by task kworker/1:2/108
[ 7.350010]
[ 7.350064] CPU: 1 UID: 0 PID: 108 Comm: kworker/1:2 Not tainted 7.0.0-rc3+ #58 PREEMPTLAZY
[ 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
[ 7.350070] Workqueue: ksmbd-io handle_ksmbd_work
[ 7.350083] Call Trace:
[ 7.350087] <TASK>
[ 7.350087] dump_stack_lvl+0x64/0x80
[ 7.350094] print_report+0xce/0x660
[ 7.350100] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 7.350101] ? __pfx___mod_timer+0x10/0x10
[ 7.350106] ? _raw_spin_lock+0x75/0xe0
[ 7.350108] kasan_report+0xce/0x100
[ 7.350109] ? _raw_spin_lock+0x75/0xe0
[ 7.350114] kasan_check_range+0x105/0x1b0
[ 7.350116] _raw_spin_lock+0x75/0xe0
[ 7.350118] ? __pfx__raw_spin_lock+0x10/0x10
[ 7.350119] ? __call_rcu_common.constprop.0+0x25e/0x780
[ 7.350125] ? close_id_del_oplock+0x2cc/0x4e0
[ 7.350128] __ksmbd_close_fd+0x27f/0xaf0
[ 7.350131] ksmbd_close_fd+0x135/0x1b0
[ 7.350133] smb2_close+0xb19/0x15b0
[ 7.350142] ? __pfx_smb2_close+0x10/0x10
[ 7.350143] ? xas_load+0x18/0x270
[ 7.350146] ? _raw_spin_lock+0x84/0xe0
[ 7.350148] ? __pfx__raw_spin_lock+0x10/0x10
[ 7.350150] ? _raw_spin_unlock+0xe/0x30
[ 7.350151] ? ksmbd_smb2_check_message+0xeb2/0x24c0
[ 7.350153] ? ksmbd_tree_conn_lookup+0xcd/0xf0
[ 7.350154] handle_ksmbd_work+0x40f/0x1080
[ 7.350156] process_one_work+0x5fa/0xef0
[ 7.350162] ? assign_work+0x122/0x3e0
[ 7.350163] worker_thread+0x54b/0xf70
[ 7.350165] ? __pfx_worker_thread+0x10/0x10
[ 7.350166] kthread+0x346/0x470
[ 7.350170] ? recalc_sigpending+0x19b/0x230
[ 7.350176] ? __pfx_kthread+0x10/0x10
[ 7.350178] ret_from_fork+0x4fb/0x6c0
[ 7.350183] ? __pfx_ret_from_fork+0x10/0x10
[ 7.350185] ? __switch_to+0x36c/0xbe0
[ 7.350188] ? __pfx_kthread+0x10/0x10
[ 7.350190] ret_from_fork_asm+0x1a/0x30
[ 7.350197] </TASK>
[ 7.350197]
[ 7.355160] Allocated by task 123:
[ 7.355261] kasan_save_stack+0x33/0x60
[ 7.355373] kasan_save_track+0x14/0x30
[ 7.355484] __kasan_kmalloc+0x8f/0xa0
[ 7.355593] ksmbd_conn_alloc+0x44/0x6d0
[ 7.355711] ksmbd_kthread_fn+0x243/0xd70
[ 7.355839] kthread+0x346/0x470
[ 7.355942] ret_from_fork+0x4fb/0x6c0
[ 7.356051] ret_from_fork_asm+0x1a/0x30
[ 7.356164]
[ 7.356214] Freed by task 134:
[ 7.356305] kasan_save_stack+0x33/0x60
[ 7.356416] kasan_save_track+0x14/0x30
[ 7.356527] kasan_save_free_info+0x3b/0x60
[ 7.356646] __kasan_slab_free+0x43/0x70
[ 7.356761] kfree+0x1ca/0x430
[ 7.356862] ksmbd_tcp_disconnect+0x59/0xe0
[ 7.356993] ksmbd_conn_handler_loop+0x77e/0xd40
[ 7.357138] kthread+0x346/0x470
[ 7.357240] ret_from_fork+0x4fb/0x6c0
[ 7.357350] ret_from_fork_asm+0x1a/0x30
[ 7.357463]
[ 7.357513] The buggy address belongs to the object at ffff8881056ac000
[ 7.357513] which belongs to the cache kmalloc-1k of size 1024
[ 7.357857] The buggy address is located 396 bytes inside of
[ 7.357857] freed 1024-byte region
---truncated---
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b0158d9d6f4ec5941e49a0b812735db2844f9975",
"status": "affected",
"version": "8df4bcdb0a4232192b2445256c39b787d58ef14d",
"versionType": "git"
},
{
"lessThan": "568a25fd7bcdfb2790f7d42aa2a440dca4435c96",
"status": "affected",
"version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
"versionType": "git"
},
{
"lessThan": "a5828c14a9e3d5eeed0bcc0a58f0f3fbca0cdcb2",
"status": "affected",
"version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
"versionType": "git"
},
{
"lessThan": "9b0792c3eacf01e67f356d6ef9707b0ae5022419",
"status": "affected",
"version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
"versionType": "git"
},
{
"lessThan": "b425e4d0eb321a1116ddbf39636333181675d8f4",
"status": "affected",
"version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"lessThan": "6.9",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.130",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.78",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.20",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.130",
"versionStartIncluding": "6.6.32",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.78",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.20",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.10",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
"versionStartIncluding": "6.9",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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-\u003efp-\u003econn\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-\u003econn, so it returns file handles that are already actively connected.\nThe unconditional overwrite replaces fp-\u003econn, and when the overwriting\nconnection is subsequently freed, __ksmbd_close_fd() dereferences the\nstale fp-\u003econn via spin_lock(\u0026fp-\u003econn-\u003ellist_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] \u003cTASK\u003e\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] \u003c/TASK\u003e\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---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-27T14:02:18.220Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/b0158d9d6f4ec5941e49a0b812735db2844f9975"
},
{
"url": "https://git.kernel.org/stable/c/568a25fd7bcdfb2790f7d42aa2a440dca4435c96"
},
{
"url": "https://git.kernel.org/stable/c/a5828c14a9e3d5eeed0bcc0a58f0f3fbca0cdcb2"
},
{
"url": "https://git.kernel.org/stable/c/9b0792c3eacf01e67f356d6ef9707b0ae5022419"
},
{
"url": "https://git.kernel.org/stable/c/b425e4d0eb321a1116ddbf39636333181675d8f4"
}
],
"title": "ksmbd: fix use-after-free in durable v2 replay of active file handles",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-23427",
"datePublished": "2026-04-03T15:15:14.183Z",
"dateReserved": "2026-01-13T15:37:46.015Z",
"dateUpdated": "2026-04-27T14:02:18.220Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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