CVE-2026-90174
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds read in ksmbd_alloc_user() ksmbd_alloc_user() copies resp->hash_sz bytes out of the mountd IPC login response with user->passkey_sz = resp->hash_sz; user->passkey = kmalloc(resp->hash_sz, KSMBD_DEFAULT_GFP); if (user->passkey) memcpy(user->passkey, resp->hash, resp->hash_sz); resp->hash_sz is a __u16 supplied by the response, but resp->hash[] is only KSMBD_REQ_MAX_HASH_SZ bytes. A malformed or malicious login response can set hash_sz well beyond that (up to 65535), so the memcpy() reads past the end of the response object. ipc_validate_msg() does not bound hash_sz, so reject any response whose hash_sz exceeds the on-stack hash[] buffer before allocating and copying. [ 2030.238706] BUG: KASAN: slab-out-of-bounds in ksmbd_alloc_user+0x278/0x680 [ 2030.240549] Read of size 65535 at addr ffff888121bb6680 by task kworker/4:1/18611 [ 2030.242296] [ 2030.242710] CPU: 4 UID: 0 PID: 18611 Comm: kworker/4:1 Not tainted 7.1.0-next-20260623-virtme #96 PREEMPT(lazy) [ 2030.242732] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 2030.242743] Workqueue: ksmbd-io handle_ksmbd_work [ 2030.242763] Call Trace: [ 2030.242769] <TASK> [ 2030.242776] dump_stack_lvl+0xa2/0xd0 [ 2030.242794] print_address_description+0x77/0x200 [ 2030.242815] ? ksmbd_alloc_user+0x278/0x680 [ 2030.242831] print_report+0x58/0x70 [ 2030.242848] kasan_report+0x117/0x150 [ 2030.242869] ? ksmbd_alloc_user+0x278/0x680 [ 2030.242888] kasan_check_range+0x3c7/0x3f0 [ 2030.242908] ? ksmbd_alloc_user+0x278/0x680 [ 2030.242925] __asan_memcpy+0x29/0x70 [ 2030.242942] ksmbd_alloc_user+0x278/0x680 [ 2030.242960] ksmbd_login_user+0xc3/0x120 [ 2030.242978] ntlm_authenticate+0x5e6/0x1b00 [ 2030.243017] ? __pfx_ntlm_authenticate+0x10/0x10 [ 2030.243035] ? ksmbd_session_lookup+0x188/0x1d0 [ 2030.243054] ? __pfx_ksmbd_session_lookup+0x10/0x10 [ 2030.243090] ? __sanitizer_cov_trace_switch+0x7b/0x140 [ 2030.243108] smb2_sess_setup+0x1e4a/0x27b0 [ 2030.243126] ? copy_from_kernel_nofault+0x199/0x300 [ 2030.243156] ? __pfx_smb2_sess_setup+0x10/0x10 [ 2030.243173] ? get_smb2_cmd_val+0xe3/0x1c0 [ 2030.243208] handle_ksmbd_work+0x954/0x1280 [ 2030.243230] ? __pfx_handle_ksmbd_work+0x10/0x10 [ 2030.243249] ? process_scheduled_works+0xa07/0x1490 [ 2030.243270] ? process_scheduled_works+0xa07/0x1490 [ 2030.243291] process_scheduled_works+0xa70/0x1490 [ 2030.243320] ? __pfx_process_scheduled_works+0x10/0x10 [ 2030.243340] ? do_raw_spin_lock+0x130/0x300 [ 2030.243358] ? lock_is_held_type+0x7b/0x110 [ 2030.243388] worker_thread+0x932/0xe20 [ 2030.243415] kthread+0x38a/0x470 [ 2030.243431] ? __pfx_worker_thread+0x10/0x10 [ 2030.243451] ? __pfx_kthread+0x10/0x10 [ 2030.243467] ret_from_fork+0x484/0x910 [ 2030.243485] ? __pfx_ret_from_fork+0x10/0x10 [ 2030.243501] ? __switch_to+0xc77/0x12c0 [ 2030.243523] ? __pfx_kthread+0x10/0x10 [ 2030.243540] ret_from_fork_asm+0x1a/0x30 [ 2030.243564] </TASK> [ 2030.243570] [ 2030.290164] Allocated by task 19279: [ 2030.290911] kasan_save_track+0x3e/0x80 [ 2030.292179] __kasan_kmalloc+0x72/0x90 [ 2030.293217] __kvmalloc_node_noprof+0x3ff/0x6b0 [ 2030.294467] handle_generic_event+0x59b/0x750 [ 2030.295345] genl_family_rcv_msg_doit+0x238/0x340 [ 2030.296553] genl_rcv_msg+0x606/0x7b0 [ 2030.297129] netlink_rcv_skb+0x22b/0x4a0 [ 2030.298500] genl_rcv+0x2d/0x40 [ 2030.299273] netlink_unicast+0x7ba/0x930 [ 2030.300019] netlink_sendmsg+0x8c3/0xb00 [ 2030.301073] __sock_sendmsg+0xec/0x140 [ 2030.301579] __sys_sendto+0x357/0x470 [ 2030.302255] __x64_sys_sendto+0xe3/0x100 [ 2030.303425] do_syscall_64+0x135/0x460 [ 2030.304763] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 2030.305594] [ 2030.305819] The buggy address belongs to the object at ffff888121bb6640 [ 2030.305819] which belongs to the cache kmalloc-192 of size 192 [ 2030.309595] The buggy address ---truncated---
View original CVE JSON
{
"id": "CVE-2026-90174",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-17T17:17:11.083",
"lastModified": "2026-10-30T13:20:45.187",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix slab-out-of-bounds read in ksmbd_alloc_user()\n\nksmbd_alloc_user() copies resp->hash_sz bytes out of the mountd IPC\nlogin response with\n\n\tuser->passkey_sz = resp->hash_sz;\n\tuser->passkey = kmalloc(resp->hash_sz, KSMBD_DEFAULT_GFP);\n\tif (user->passkey)\n\t\tmemcpy(user->passkey, resp->hash, resp->hash_sz);\n\nresp->hash_sz is a __u16 supplied by the response, but resp->hash[] is\nonly KSMBD_REQ_MAX_HASH_SZ bytes. A malformed or malicious login\nresponse can set hash_sz well beyond that (up to 65535), so the memcpy()\nreads past the end of the response object. ipc_validate_msg() does not\nbound hash_sz, so reject any response whose hash_sz exceeds the on-stack\nhash[] buffer before allocating and copying.\n\n[ 2030.238706] BUG: KASAN: slab-out-of-bounds in ksmbd_alloc_user+0x278/0x680\n[ 2030.240549] Read of size 65535 at addr ffff888121bb6680 by task kworker/4:1/18611\n[ 2030.242296]\n[ 2030.242710] CPU: 4 UID: 0 PID: 18611 Comm: kworker/4:1 Not tainted 7.1.0-next-20260623-virtme #96 PREEMPT(lazy)\n[ 2030.242732] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 2030.242743] Workqueue: ksmbd-io handle_ksmbd_work\n[ 2030.242763] Call Trace:\n[ 2030.242769] <TASK>\n[ 2030.242776] dump_stack_lvl+0xa2/0xd0\n[ 2030.242794] print_address_description+0x77/0x200\n[ 2030.242815] ? ksmbd_alloc_user+0x278/0x680\n[ 2030.242831] print_report+0x58/0x70\n[ 2030.242848] kasan_report+0x117/0x150\n[ 2030.242869] ? ksmbd_alloc_user+0x278/0x680\n[ 2030.242888] kasan_check_range+0x3c7/0x3f0\n[ 2030.242908] ? ksmbd_alloc_user+0x278/0x680\n[ 2030.242925] __asan_memcpy+0x29/0x70\n[ 2030.242942] ksmbd_alloc_user+0x278/0x680\n[ 2030.242960] ksmbd_login_user+0xc3/0x120\n[ 2030.242978] ntlm_authenticate+0x5e6/0x1b00\n[ 2030.243017] ? __pfx_ntlm_authenticate+0x10/0x10\n[ 2030.243035] ? ksmbd_session_lookup+0x188/0x1d0\n[ 2030.243054] ? __pfx_ksmbd_session_lookup+0x10/0x10\n[ 2030.243090] ? __sanitizer_cov_trace_switch+0x7b/0x140\n[ 2030.243108] smb2_sess_setup+0x1e4a/0x27b0\n[ 2030.243126] ? copy_from_kernel_nofault+0x199/0x300\n[ 2030.243156] ? __pfx_smb2_sess_setup+0x10/0x10\n[ 2030.243173] ? get_smb2_cmd_val+0xe3/0x1c0\n[ 2030.243208] handle_ksmbd_work+0x954/0x1280\n[ 2030.243230] ? __pfx_handle_ksmbd_work+0x10/0x10\n[ 2030.243249] ? process_scheduled_works+0xa07/0x1490\n[ 2030.243270] ? process_scheduled_works+0xa07/0x1490\n[ 2030.243291] process_scheduled_works+0xa70/0x1490\n[ 2030.243320] ? __pfx_process_scheduled_works+0x10/0x10\n[ 2030.243340] ? do_raw_spin_lock+0x130/0x300\n[ 2030.243358] ? lock_is_held_type+0x7b/0x110\n[ 2030.243388] worker_thread+0x932/0xe20\n[ 2030.243415] kthread+0x38a/0x470\n[ 2030.243431] ? __pfx_worker_thread+0x10/0x10\n[ 2030.243451] ? __pfx_kthread+0x10/0x10\n[ 2030.243467] ret_from_fork+0x484/0x910\n[ 2030.243485] ? __pfx_ret_from_fork+0x10/0x10\n[ 2030.243501] ? __switch_to+0xc77/0x12c0\n[ 2030.243523] ? __pfx_kthread+0x10/0x10\n[ 2030.243540] ret_from_fork_asm+0x1a/0x30\n[ 2030.243564] </TASK>\n[ 2030.243570]\n[ 2030.290164] Allocated by task 19279:\n[ 2030.290911] kasan_save_track+0x3e/0x80\n[ 2030.292179] __kasan_kmalloc+0x72/0x90\n[ 2030.293217] __kvmalloc_node_noprof+0x3ff/0x6b0\n[ 2030.294467] handle_generic_event+0x59b/0x750\n[ 2030.295345] genl_family_rcv_msg_doit+0x238/0x340\n[ 2030.296553] genl_rcv_msg+0x606/0x7b0\n[ 2030.297129] netlink_rcv_skb+0x22b/0x4a0\n[ 2030.298500] genl_rcv+0x2d/0x40\n[ 2030.299273] netlink_unicast+0x7ba/0x930\n[ 2030.300019] netlink_sendmsg+0x8c3/0xb00\n[ 2030.301073] __sock_sendmsg+0xec/0x140\n[ 2030.301579] __sys_sendto+0x357/0x470\n[ 2030.302255] __x64_sys_sendto+0xe3/0x100\n[ 2030.303425] do_syscall_64+0x135/0x460\n[ 2030.304763] entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[ 2030.305594]\n[ 2030.305819] The buggy address belongs to the object at ffff888121bb6640\n[ 2030.305819] which belongs to the cache kmalloc-192 of size 192\n[ 2030.309595] The buggy address \n---truncated---"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/smb/server/mgmt/user_config.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "792dd35013427995e742c7928ef5b564434a4321",
"versionType": "git",
"status": "affected"
},
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "67223b1150a9edea52350d8cd085ea9081beaa45",
"versionType": "git",
"status": "affected"
},
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "863f74ad158fef2987b9146f29d4b3149bb95953",
"versionType": "git",
"status": "affected"
},
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "272c05a51285fe3495ab2f7eb77a48ad831b929f",
"versionType": "git",
"status": "affected"
},
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "497c221bf6b2f659511719a6acfae84cc1be1caf",
"versionType": "git",
"status": "affected"
},
{
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"lessThan": "7405d0ba294306721843bc551611775e6edef516",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/smb/server/mgmt/user_config.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.15",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.15",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.2
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/272c05a51285fe3495ab2f7eb77a48ad831b929f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/497c221bf6b2f659511719a6acfae84cc1be1caf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/67223b1150a9edea52350d8cd085ea9081beaa45",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7405d0ba294306721843bc551611775e6edef516",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/792dd35013427995e742c7928ef5b564434a4321",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/863f74ad158fef2987b9146f29d4b3149bb95953",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}