CVE-2024-50106 (GCVE-0-2024-50106)

Vulnerability from cvelistv5 – Published: 2024-11-05 17:10 – Updated: 2026-08-05 11:41
VLAI
Title
nfsd: fix race between laundromat and free_stateid
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix race between laundromat and free_stateid There is a race between laundromat handling of revoked delegations and a client sending free_stateid operation. Laundromat thread finds that delegation has expired and needs to be revoked so it marks the delegation stid revoked and it puts it on a reaper list but then it unlock the state lock and the actual delegation revocation happens without the lock. Once the stid is marked revoked a racing free_stateid processing thread does the following (1) it calls list_del_init() which removes it from the reaper list and (2) frees the delegation stid structure. The laundromat thread ends up not calling the revoke_delegation() function for this particular delegation but that means it will no release the lock lease that exists on the file. Now, a new open for this file comes in and ends up finding that lease list isn't empty and calls nfsd_breaker_owns_lease() which ends up trying to derefence a freed delegation stateid. Leading to the followint use-after-free KASAN warning: kernel: ================================================================== kernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205 kernel: kernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9 kernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024 kernel: Call trace: kernel: dump_backtrace+0x98/0x120 kernel: show_stack+0x1c/0x30 kernel: dump_stack_lvl+0x80/0xe8 kernel: print_address_description.constprop.0+0x84/0x390 kernel: print_report+0xa4/0x268 kernel: kasan_report+0xb4/0xf8 kernel: __asan_report_load8_noabort+0x1c/0x28 kernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd] kernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd] kernel: nfs4_get_vfs_file+0x634/0x958 [nfsd] kernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd] kernel: nfsd4_open+0xa08/0xe80 [nfsd] kernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd] kernel: nfsd_dispatch+0x22c/0x718 [nfsd] kernel: svc_process_common+0x8e8/0x1960 [sunrpc] kernel: svc_process+0x3d4/0x7e0 [sunrpc] kernel: svc_handle_xprt+0x828/0xe10 [sunrpc] kernel: svc_recv+0x2cc/0x6a8 [sunrpc] kernel: nfsd+0x270/0x400 [nfsd] kernel: kthread+0x288/0x310 kernel: ret_from_fork+0x10/0x20 This patch proposes a fixed that's based on adding 2 new additional stid's sc_status values that help coordinate between the laundromat and other operations (nfsd4_free_stateid() and nfsd4_delegreturn()). First to make sure, that once the stid is marked revoked, it is not removed by the nfsd4_free_stateid(), the laundromat take a reference on the stateid. Then, coordinating whether the stid has been put on the cl_revoked list or we are processing FREE_STATEID and need to make sure to remove it from the list, each check that state and act accordingly. If laundromat has added to the cl_revoke list before the arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove it from the list. If nfsd4_free_stateid() finds that operations arrived before laundromat has placed it on cl_revoke list, it marks the state freed and then laundromat will no longer add it to the list. Also, for nfsd4_delegreturn() when looking for the specified stid, we need to access stid that are marked removed or freeable, it means the laundromat has started processing it but hasn't finished and this delegreturn needs to return nfserr_deleg_revoked and not nfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the lack of it will leave this stid on the cl_revoked list indefinitely.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-12-11 14:48 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 83e733161fde43e2f99cefa68e369944460fce39 , < 967faa26f313a62e7bebc55d5b8122eaee43b929 (git)
Affected: 83e733161fde43e2f99cefa68e369944460fce39 , < 8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a (git)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.11.6 , ≤ 6.11.* (semver)
Unaffected: 6.12 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix race between laundromat and free_stateid\n\nThere is a race between laundromat handling of revoked delegations\nand a client sending free_stateid operation. Laundromat thread\nfinds that delegation has expired and needs to be revoked so it\nmarks the delegation stid revoked and it puts it on a reaper list\nbut then it unlock the state lock and the actual delegation revocation\nhappens without the lock. Once the stid is marked revoked a racing\nfree_stateid processing thread does the following (1) it calls\nlist_del_init() which removes it from the reaper list and (2) frees\nthe delegation stid structure. The laundromat thread ends up not\ncalling the revoke_delegation() function for this particular delegation\nbut that means it will no release the lock lease that exists on\nthe file.\n\nNow, a new open for this file comes in and ends up finding that\nlease list isn\u0027t empty and calls nfsd_breaker_owns_lease() which ends\nup trying to derefence a freed delegation stateid. Leading to the\nfollowint use-after-free KASAN warning:\n\nkernel: ==================================================================\nkernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205\nkernel:\nkernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9\nkernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024\nkernel: Call trace:\nkernel: dump_backtrace+0x98/0x120\nkernel: show_stack+0x1c/0x30\nkernel: dump_stack_lvl+0x80/0xe8\nkernel: print_address_description.constprop.0+0x84/0x390\nkernel: print_report+0xa4/0x268\nkernel: kasan_report+0xb4/0xf8\nkernel: __asan_report_load8_noabort+0x1c/0x28\nkernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]\nkernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]\nkernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]\nkernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]\nkernel: nfsd4_open+0xa08/0xe80 [nfsd]\nkernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]\nkernel: nfsd_dispatch+0x22c/0x718 [nfsd]\nkernel: svc_process_common+0x8e8/0x1960 [sunrpc]\nkernel: svc_process+0x3d4/0x7e0 [sunrpc]\nkernel: svc_handle_xprt+0x828/0xe10 [sunrpc]\nkernel: svc_recv+0x2cc/0x6a8 [sunrpc]\nkernel: nfsd+0x270/0x400 [nfsd]\nkernel: kthread+0x288/0x310\nkernel: ret_from_fork+0x10/0x20\n\nThis patch proposes a fixed that\u0027s based on adding 2 new additional\nstid\u0027s sc_status values that help coordinate between the laundromat\nand other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).\n\nFirst to make sure, that once the stid is marked revoked, it is not\nremoved by the nfsd4_free_stateid(), the laundromat take a reference\non the stateid. Then, coordinating whether the stid has been put\non the cl_revoked list or we are processing FREE_STATEID and need to\nmake sure to remove it from the list, each check that state and act\naccordingly. If laundromat has added to the cl_revoke list before\nthe arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove\nit from the list. If nfsd4_free_stateid() finds that operations arrived\nbefore laundromat has placed it on cl_revoke list, it marks the state\nfreed and then laundromat will no longer add it to the list.\n\nAlso, for nfsd4_delegreturn() when looking for the specified stid,\nwe need to access stid that are marked removed or freeable, it means\nthe laundromat has started processing it but hasn\u0027t finished and this\ndelegreturn needs to return nfserr_deleg_revoked and not\nnfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the\nlack of it will leave this stid on the cl_revoked list indefinitely."
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              "value": "AV:N - The vulnerability is in the in-kernel NFS server (nfsd) and is driven entirely by NFSv4.1 protocol operations (OPEN, FREE_STATEID, DELEGRETURN) arriving over TCP/2049 from a remote client, as shown by the `svc_recv`/`svc_process`/`nfsd4_proc_compound` call chain in the report. No local access to the server is needed.\nAC:L - The attacker controls both sides: it creates the delegation, forces the recall with its own conflicting OPEN, learns the exact revocation deadline from the server-supplied FATTR4_LEASE_TIME attribute, and then issues FREE_STATEID at will; queuing many delegations stretches the laundromat\u0027s per-item `kernel_setlease(F_UNLCK)` window to milliseconds and the whole sequence can be retried indefinitely.\nPR:N - Reaching `nfsd4_free_stateid()` requires only an NFSv4.1 session established via EXCHANGE_ID/CREATE_SESSION plus an OPEN, and under the default AUTH_SYS security flavor no credentials are ever verified \u2014 the client merely asserts an identity, with only host-based export matching as a gate, matching the treatment of client-triggerable nfsd state-handling flaws.\nUI:N - The attacker performs every step itself \u2014 obtaining the delegation, triggering the recall from a second client identity, letting the lease expire, racing FREE_STATEID, and then re-opening the file to trip the dangling lease. No action by any local user or administrator is required.\nS:U - The freed `nfs4_delegation`, the `file_lease` on the inode, and the corrupted slab memory all belong to the kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a slab use-after-free: `nfsd_breaker_owns_lease()` and `nfsd_break_deleg_cb()` read `dl_stid.sc_client`, `sc_file` and `dl_recall` out of the freed `nfs4_delegation`, and since `deleg_slab` is created with flags 0 (mergeable) and can be refilled at will by acquiring new delegations, the attacker controls the reclaimed contents and can turn the dereferences into an arbitrary kernel-memory read.\nI:H - The dangling lease gives direct write primitives \u2014 `dp-\u003edl_recalled = true` into freed memory, `atomic_inc(\u0026clp-\u003ecl_delegs_in_recall)` and `fp-\u003efi_had_conflict = true` through pointers sourced from the freed object, `refcount_inc()` on freed state \u2014 and `nfsd4_run_cb(\u0026dp-\u003edl_recall)` performs an indirect call through a `cb-\u003ecb_ops` table read from reclaimed memory, a direct path to heap corruption and control-flow hijack.\nA:H - The changelog documents a KASAN slab-use-after-free oops in `nfsd_breaker_owns_lease()` inside an nfsd kthread, and the leaked lease plus the `DELEGRETURN` returning `nfserr_bad_stateid` strands stateids on `cl_revoked` and pins `nfsd_file`/inode references indefinitely; the crash kills the NFS service and can be reproduced at will."
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          "url": "https://git.kernel.org/stable/c/8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix race between laundromat and free_stateid\n\nThere is a race between laundromat handling of revoked delegations\nand a client sending free_stateid operation. Laundromat thread\nfinds that delegation has expired and needs to be revoked so it\nmarks the delegation stid revoked and it puts it on a reaper list\nbut then it unlock the state lock and the actual delegation revocation\nhappens without the lock. Once the stid is marked revoked a racing\nfree_stateid processing thread does the following (1) it calls\nlist_del_init() which removes it from the reaper list and (2) frees\nthe delegation stid structure. The laundromat thread ends up not\ncalling the revoke_delegation() function for this particular delegation\nbut that means it will no release the lock lease that exists on\nthe file.\n\nNow, a new open for this file comes in and ends up finding that\nlease list isn\u0027t empty and calls nfsd_breaker_owns_lease() which ends\nup trying to derefence a freed delegation stateid. Leading to the\nfollowint use-after-free KASAN warning:\n\nkernel: ==================================================================\nkernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205\nkernel:\nkernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9\nkernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024\nkernel: Call trace:\nkernel: dump_backtrace+0x98/0x120\nkernel: show_stack+0x1c/0x30\nkernel: dump_stack_lvl+0x80/0xe8\nkernel: print_address_description.constprop.0+0x84/0x390\nkernel: print_report+0xa4/0x268\nkernel: kasan_report+0xb4/0xf8\nkernel: __asan_report_load8_noabort+0x1c/0x28\nkernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]\nkernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]\nkernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]\nkernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]\nkernel: nfsd4_open+0xa08/0xe80 [nfsd]\nkernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]\nkernel: nfsd_dispatch+0x22c/0x718 [nfsd]\nkernel: svc_process_common+0x8e8/0x1960 [sunrpc]\nkernel: svc_process+0x3d4/0x7e0 [sunrpc]\nkernel: svc_handle_xprt+0x828/0xe10 [sunrpc]\nkernel: svc_recv+0x2cc/0x6a8 [sunrpc]\nkernel: nfsd+0x270/0x400 [nfsd]\nkernel: kthread+0x288/0x310\nkernel: ret_from_fork+0x10/0x20\n\nThis patch proposes a fixed that\u0027s based on adding 2 new additional\nstid\u0027s sc_status values that help coordinate between the laundromat\nand other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).\n\nFirst to make sure, that once the stid is marked revoked, it is not\nremoved by the nfsd4_free_stateid(), the laundromat take a reference\non the stateid. Then, coordinating whether the stid has been put\non the cl_revoked list or we are processing FREE_STATEID and need to\nmake sure to remove it from the list, each check that state and act\naccordingly. If laundromat has added to the cl_revoke list before\nthe arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove\nit from the list. If nfsd4_free_stateid() finds that operations arrived\nbefore laundromat has placed it on cl_revoke list, it marks the state\nfreed and then laundromat will no longer add it to the list.\n\nAlso, for nfsd4_delegreturn() when looking for the specified stid,\nwe need to access stid that are marked removed or freeable, it means\nthe laundromat has started processing it but hasn\u0027t finished and this\ndelegreturn needs to return nfserr_deleg_revoked and not\nnfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the\nlack of it will leave this stid on the cl_revoked list indefinitely."
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        {
          "lang": "es",
          "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nfsd: arregla la ejecuci\u00f3n entre laundromat y free_stateid. Hay una ejecuci\u00f3n entre el manejo de laundromat de delegaciones revocadas y un cliente que env\u00eda la operaci\u00f3n free_stateid. El hilo de laundromat encuentra que la delegaci\u00f3n ha expirado y necesita ser revocada, por lo que marca el stid de delegaci\u00f3n revocado y lo pone en una lista de reaper, pero luego desbloquea el bloqueo de estado y la revocaci\u00f3n de delegaci\u00f3n real ocurre sin el bloqueo. Una vez que el stid est\u00e1 marcado como revocado, un hilo de procesamiento de free_stateid en ejecuci\u00f3n hace lo siguiente: (1) llama a list_del_init() que lo elimina de la lista de reaper y (2) libera la estructura del stid de delegaci\u00f3n. El hilo de laundromat termina sin llamar a la funci\u00f3n revoke_delegation() para esta delegaci\u00f3n en particular, pero eso significa que no liberar\u00e1 la concesi\u00f3n de bloqueo que existe en el archivo. Ahora, una nueva apertura para este archivo llega y termina encontrando que la lista de arrendamientos no est\u00e1 vac\u00eda y llama a nfsd_breaker_owns_lease() que termina intentando desreferenciar un stateid de delegaci\u00f3n liberado. Lo que genera la siguiente advertencia de KASAN de use-after-free: kernel: == ... 2069.0.0.0.0 08/03/2024 n\u00facleo: Seguimiento de llamadas: n\u00facleo: dump_backtrace+0x98/0x120 n\u00facleo: show_stack+0x1c/0x30 n\u00facleo: dump_stack_lvl+0x80/0xe8 n\u00facleo: print_address_description.constprop.0+0x84/0x390 n\u00facleo: print_report+0xa4/0x268 n\u00facleo: kasan_report+0xb4/0xf8 n\u00facleo: __asan_report_load8_noabort+0x1c/0x28 n\u00facleo: nfsd_breaker_owns_lease+0x140/0x160 [nfsd] n\u00facleo: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd] n\u00facleo: nfsd_file_acquire_opened+0x84/0x110 [nfsd] n\u00facleo: nfs4_get_vfs_file+0x634/0x958 [nfsd] n\u00facleo: nfsd4_process_open2+0xa40/0x1a40 [nfsd] n\u00facleo: nfsd4_open+0xa08/0xe80 [nfsd] n\u00facleo: nfsd4_proc_compound+0xb8c/0x2130 [nfsd] n\u00facleo: nfsd_dispatch+0x22c/0x718 [nfsd] n\u00facleo: svc_process_common+0x8e8/0x1960 [sunrpc] n\u00facleo: svc_process+0x3d4/0x7e0 [sunrpc] n\u00facleo: svc_handle_xprt+0x828/0xe10 [sunrpc] kernel: svc_recv+0x2cc/0x6a8 [sunrpc] kernel: nfsd+0x270/0x400 [nfsd] kernel: kthread+0x288/0x310 kernel: ret_from_fork+0x10/0x20 Este parche propone una soluci\u00f3n basada en agregar 2 nuevos valores de stid adicionales sc_status que ayudan a coordinar entre la lavander\u00eda y otras operaciones (nfsd4_free_stateid() y nfsd4_delegreturn()). Primero, para asegurarse de que una vez que el stid est\u00e9 marcado como revocado, no sea eliminado por nfsd4_free_stateid(), la lavander\u00eda tome una referencia en el stateid. Luego, al coordinar si el stid se ha colocado en la lista cl_revoked o si estamos procesando FREE_STATEID y debemos asegurarnos de eliminarlo de la lista, cada uno verifica ese estado y act\u00faa en consecuencia. Si laundromat ha agregado a la lista cl_revoke antes de la llegada de FREE_STATEID, entonces nfsd4_free_stateid() sabe eliminarlo de la lista. Si nfsd4_free_stateid() encuentra que las operaciones llegaron antes de que laundromat lo haya colocado en la lista cl_revoke, marca el estado como liberado y luego laundromat ya no lo agregar\u00e1 a la lista. Adem\u00e1s, para nfsd4_delegreturn() cuando buscamos el stid especificado, necesitamos acceder a los stid que est\u00e1n marcados como eliminados o liberables, significa que laundromat ha comenzado a procesarlo pero no ha terminado y este delegreturn debe devolver nfserr_deleg_revoked y no nfserr_bad_stateid. Este \u00faltimo no activar\u00e1 un FREE_STATEID y la falta del mismo dejar\u00e1 este stid en la lista cl_revoked indefinidamente."
        }
      ],
      "id": "CVE-2024-50106",
      "lastModified": "2024-12-11T15:15:11.693",
      "metrics": {
        "cvssMetricV31": [
          {
            "cvssData": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
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              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
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              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
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            "source": "nvd@nist.gov",
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              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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            },
            "exploitabilityScore": 1.8,
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            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
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      },
      "published": "2024-11-05T18:15:14.120",
      "references": [
        {
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "tags": [
            "Patch"
          ],
          "url": "https://git.kernel.org/stable/c/8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a"
        },
        {
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        }
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      "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "vulnStatus": "Modified",
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              "value": "CWE-416"
            }
          ],
          "source": "nvd@nist.gov",
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        },
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              "value": "CWE-416"
            }
          ],
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          "type": "Secondary"
        }
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    },
    "nvd": {
      "cve": {
        "affected": [
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            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "fs/nfsd/nfs4state.c",
                  "fs/nfsd/state.h"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
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                    "status": "affected",
                    "version": "83e733161fde43e2f99cefa68e369944460fce39",
                    "versionType": "git"
                  },
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                    "status": "affected",
                    "version": "83e733161fde43e2f99cefa68e369944460fce39",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "fs/nfsd/nfs4state.c",
                  "fs/nfsd/state.h"
                ],
                "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": "6.11.*",
                    "status": "unaffected",
                    "version": "6.11.6",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "6.12",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "570099BE-0B19-4950-8FD5-4E24B814E579",
                    "versionEndExcluding": "6.11.6",
                    "versionStartIncluding": "3.17",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*",
                    "matchCriteriaId": "7F361E1D-580F-4A2D-A509-7615F73167A1",
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                  },
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                    "matchCriteriaId": "925478D0-3E3D-4E6F-ACD5-09F28D5DF82C",
                    "vulnerable": true
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                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*",
                    "matchCriteriaId": "3C95E234-D335-4B6C-96BF-E2CEBD8654ED",
                    "vulnerable": true
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                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:*",
                    "matchCriteriaId": "E0F717D8-3014-4F84-8086-0124B2111379",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix race between laundromat and free_stateid\n\nThere is a race between laundromat handling of revoked delegations\nand a client sending free_stateid operation. Laundromat thread\nfinds that delegation has expired and needs to be revoked so it\nmarks the delegation stid revoked and it puts it on a reaper list\nbut then it unlock the state lock and the actual delegation revocation\nhappens without the lock. Once the stid is marked revoked a racing\nfree_stateid processing thread does the following (1) it calls\nlist_del_init() which removes it from the reaper list and (2) frees\nthe delegation stid structure. The laundromat thread ends up not\ncalling the revoke_delegation() function for this particular delegation\nbut that means it will no release the lock lease that exists on\nthe file.\n\nNow, a new open for this file comes in and ends up finding that\nlease list isn\u0027t empty and calls nfsd_breaker_owns_lease() which ends\nup trying to derefence a freed delegation stateid. Leading to the\nfollowint use-after-free KASAN warning:\n\nkernel: ==================================================================\nkernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205\nkernel:\nkernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9\nkernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024\nkernel: Call trace:\nkernel: dump_backtrace+0x98/0x120\nkernel: show_stack+0x1c/0x30\nkernel: dump_stack_lvl+0x80/0xe8\nkernel: print_address_description.constprop.0+0x84/0x390\nkernel: print_report+0xa4/0x268\nkernel: kasan_report+0xb4/0xf8\nkernel: __asan_report_load8_noabort+0x1c/0x28\nkernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]\nkernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]\nkernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]\nkernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]\nkernel: nfsd4_open+0xa08/0xe80 [nfsd]\nkernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]\nkernel: nfsd_dispatch+0x22c/0x718 [nfsd]\nkernel: svc_process_common+0x8e8/0x1960 [sunrpc]\nkernel: svc_process+0x3d4/0x7e0 [sunrpc]\nkernel: svc_handle_xprt+0x828/0xe10 [sunrpc]\nkernel: svc_recv+0x2cc/0x6a8 [sunrpc]\nkernel: nfsd+0x270/0x400 [nfsd]\nkernel: kthread+0x288/0x310\nkernel: ret_from_fork+0x10/0x20\n\nThis patch proposes a fixed that\u0027s based on adding 2 new additional\nstid\u0027s sc_status values that help coordinate between the laundromat\nand other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).\n\nFirst to make sure, that once the stid is marked revoked, it is not\nremoved by the nfsd4_free_stateid(), the laundromat take a reference\non the stateid. Then, coordinating whether the stid has been put\non the cl_revoked list or we are processing FREE_STATEID and need to\nmake sure to remove it from the list, each check that state and act\naccordingly. If laundromat has added to the cl_revoke list before\nthe arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove\nit from the list. If nfsd4_free_stateid() finds that operations arrived\nbefore laundromat has placed it on cl_revoke list, it marks the state\nfreed and then laundromat will no longer add it to the list.\n\nAlso, for nfsd4_delegreturn() when looking for the specified stid,\nwe need to access stid that are marked removed or freeable, it means\nthe laundromat has started processing it but hasn\u0027t finished and this\ndelegreturn needs to return nfserr_deleg_revoked and not\nnfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the\nlack of it will leave this stid on the cl_revoked list indefinitely."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nfsd: arregla la ejecuci\u00f3n entre laundromat y free_stateid. Hay una ejecuci\u00f3n entre el manejo de laundromat de delegaciones revocadas y un cliente que env\u00eda la operaci\u00f3n free_stateid. El hilo de laundromat encuentra que la delegaci\u00f3n ha expirado y necesita ser revocada, por lo que marca el stid de delegaci\u00f3n revocado y lo pone en una lista de reaper, pero luego desbloquea el bloqueo de estado y la revocaci\u00f3n de delegaci\u00f3n real ocurre sin el bloqueo. Una vez que el stid est\u00e1 marcado como revocado, un hilo de procesamiento de free_stateid en ejecuci\u00f3n hace lo siguiente: (1) llama a list_del_init() que lo elimina de la lista de reaper y (2) libera la estructura del stid de delegaci\u00f3n. El hilo de laundromat termina sin llamar a la funci\u00f3n revoke_delegation() para esta delegaci\u00f3n en particular, pero eso significa que no liberar\u00e1 la concesi\u00f3n de bloqueo que existe en el archivo. Ahora, una nueva apertura para este archivo llega y termina encontrando que la lista de arrendamientos no est\u00e1 vac\u00eda y llama a nfsd_breaker_owns_lease() que termina intentando desreferenciar un stateid de delegaci\u00f3n liberado. Lo que genera la siguiente advertencia de KASAN de use-after-free: kernel: == ... 2069.0.0.0.0 08/03/2024 n\u00facleo: Seguimiento de llamadas: n\u00facleo: dump_backtrace+0x98/0x120 n\u00facleo: show_stack+0x1c/0x30 n\u00facleo: dump_stack_lvl+0x80/0xe8 n\u00facleo: print_address_description.constprop.0+0x84/0x390 n\u00facleo: print_report+0xa4/0x268 n\u00facleo: kasan_report+0xb4/0xf8 n\u00facleo: __asan_report_load8_noabort+0x1c/0x28 n\u00facleo: nfsd_breaker_owns_lease+0x140/0x160 [nfsd] n\u00facleo: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd] n\u00facleo: nfsd_file_acquire_opened+0x84/0x110 [nfsd] n\u00facleo: nfs4_get_vfs_file+0x634/0x958 [nfsd] n\u00facleo: nfsd4_process_open2+0xa40/0x1a40 [nfsd] n\u00facleo: nfsd4_open+0xa08/0xe80 [nfsd] n\u00facleo: nfsd4_proc_compound+0xb8c/0x2130 [nfsd] n\u00facleo: nfsd_dispatch+0x22c/0x718 [nfsd] n\u00facleo: svc_process_common+0x8e8/0x1960 [sunrpc] n\u00facleo: svc_process+0x3d4/0x7e0 [sunrpc] n\u00facleo: svc_handle_xprt+0x828/0xe10 [sunrpc] kernel: svc_recv+0x2cc/0x6a8 [sunrpc] kernel: nfsd+0x270/0x400 [nfsd] kernel: kthread+0x288/0x310 kernel: ret_from_fork+0x10/0x20 Este parche propone una soluci\u00f3n basada en agregar 2 nuevos valores de stid adicionales sc_status que ayudan a coordinar entre la lavander\u00eda y otras operaciones (nfsd4_free_stateid() y nfsd4_delegreturn()). Primero, para asegurarse de que una vez que el stid est\u00e9 marcado como revocado, no sea eliminado por nfsd4_free_stateid(), la lavander\u00eda tome una referencia en el stateid. Luego, al coordinar si el stid se ha colocado en la lista cl_revoked o si estamos procesando FREE_STATEID y debemos asegurarnos de eliminarlo de la lista, cada uno verifica ese estado y act\u00faa en consecuencia. Si laundromat ha agregado a la lista cl_revoke antes de la llegada de FREE_STATEID, entonces nfsd4_free_stateid() sabe eliminarlo de la lista. Si nfsd4_free_stateid() encuentra que las operaciones llegaron antes de que laundromat lo haya colocado en la lista cl_revoke, marca el estado como liberado y luego laundromat ya no lo agregar\u00e1 a la lista. Adem\u00e1s, para nfsd4_delegreturn() cuando buscamos el stid especificado, necesitamos acceder a los stid que est\u00e1n marcados como eliminados o liberables, significa que laundromat ha comenzado a procesarlo pero no ha terminado y este delegreturn debe devolver nfserr_deleg_revoked y no nfserr_bad_stateid. Este \u00faltimo no activar\u00e1 un FREE_STATEID y la falta del mismo dejar\u00e1 este stid en la lista cl_revoked indefinidamente."
          }
        ],
        "id": "CVE-2024-50106",
        "lastModified": "2026-08-04T11:21:20.310",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
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                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
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              "exploitabilityScore": 3.9,
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              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
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                "integrityImpact": "HIGH",
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                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.0,
              "impactScore": 5.9,
              "source": "nvd@nist.gov",
              "type": "Primary"
            },
            {
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                "availabilityImpact": "HIGH",
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                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2024-50106",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-12-11T14:48:58.818962Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2024-11-05T18:15:14.120",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
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            "url": "https://git.kernel.org/stable/c/967faa26f313a62e7bebc55d5b8122eaee43b929"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-05T12:22:44+00:00",
      "cve": "CVE-2024-50106",
      "id": "CVE-2024-50106",
      "initial_release_date": "2024-11-05T00:00:00+00:00",
      "product_status:fixed": "305",
      "product_status:known_affected": "112",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: nfsd: fix race between laundromat and free_stateid",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2024/cve-2024-50106.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-23T00:49:33Z",
      "cve": "CVE-2024-50106",
      "id": "CVE-2024-50106",
      "initial_release_date": "2024-11-06T03:49:07Z",
      "product_status:known_affected": "811",
      "product_status:known_not_affected": "33",
      "product_status:recommended": "419",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2024-50106",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2024-50106.json",
      "version": "99"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "LOCAL",
                  "availabilityImpact": "HIGH",
                  "baseScore": 7.8,
                  "baseSeverity": "HIGH",
                  "confidentialityImpact": "HIGH",
                  "integrityImpact": "HIGH",
                  "privilegesRequired": "LOW",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2024-50106",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2024-12-11T14:48:58.818962Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "cweId": "CWE-416",
                    "description": "CWE-416 Use After Free",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2024-12-11T14:49:00.556Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "Linux",
              "programFiles": [
                "fs/nfsd/nfs4state.c",
                "fs/nfsd/state.h"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
                  "lessThan": "967faa26f313a62e7bebc55d5b8122eaee43b929",
                  "status": "affected",
                  "version": "83e733161fde43e2f99cefa68e369944460fce39",
                  "versionType": "git"
                },
                {
                  "lessThan": "8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a",
                  "status": "affected",
                  "version": "83e733161fde43e2f99cefa68e369944460fce39",
                  "versionType": "git"
                }
              ]
            },
            {
              "defaultStatus": "affected",
              "product": "Linux",
              "programFiles": [
                "fs/nfsd/nfs4state.c",
                "fs/nfsd/state.h"
              ],
              "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": "6.11.*",
                  "status": "unaffected",
                  "version": "6.11.6",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "*",
                  "status": "unaffected",
                  "version": "6.12",
                  "versionType": "original_commit_for_fix"
                }
              ]
            }
          ],
          "cpeApplicability": [
            {
              "nodes": [
                {
                  "cpeMatch": [
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "6.11.6",
                      "versionStartIncluding": "6.9",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "6.12",
                      "versionStartIncluding": "6.9",
                      "vulnerable": true
                    }
                  ],
                  "negate": false,
                  "operator": "OR"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix race between laundromat and free_stateid\n\nThere is a race between laundromat handling of revoked delegations\nand a client sending free_stateid operation. Laundromat thread\nfinds that delegation has expired and needs to be revoked so it\nmarks the delegation stid revoked and it puts it on a reaper list\nbut then it unlock the state lock and the actual delegation revocation\nhappens without the lock. Once the stid is marked revoked a racing\nfree_stateid processing thread does the following (1) it calls\nlist_del_init() which removes it from the reaper list and (2) frees\nthe delegation stid structure. The laundromat thread ends up not\ncalling the revoke_delegation() function for this particular delegation\nbut that means it will no release the lock lease that exists on\nthe file.\n\nNow, a new open for this file comes in and ends up finding that\nlease list isn\u0027t empty and calls nfsd_breaker_owns_lease() which ends\nup trying to derefence a freed delegation stateid. Leading to the\nfollowint use-after-free KASAN warning:\n\nkernel: ==================================================================\nkernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205\nkernel:\nkernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9\nkernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024\nkernel: Call trace:\nkernel: dump_backtrace+0x98/0x120\nkernel: show_stack+0x1c/0x30\nkernel: dump_stack_lvl+0x80/0xe8\nkernel: print_address_description.constprop.0+0x84/0x390\nkernel: print_report+0xa4/0x268\nkernel: kasan_report+0xb4/0xf8\nkernel: __asan_report_load8_noabort+0x1c/0x28\nkernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]\nkernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]\nkernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]\nkernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]\nkernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]\nkernel: nfsd4_open+0xa08/0xe80 [nfsd]\nkernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]\nkernel: nfsd_dispatch+0x22c/0x718 [nfsd]\nkernel: svc_process_common+0x8e8/0x1960 [sunrpc]\nkernel: svc_process+0x3d4/0x7e0 [sunrpc]\nkernel: svc_handle_xprt+0x828/0xe10 [sunrpc]\nkernel: svc_recv+0x2cc/0x6a8 [sunrpc]\nkernel: nfsd+0x270/0x400 [nfsd]\nkernel: kthread+0x288/0x310\nkernel: ret_from_fork+0x10/0x20\n\nThis patch proposes a fixed that\u0027s based on adding 2 new additional\nstid\u0027s sc_status values that help coordinate between the laundromat\nand other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).\n\nFirst to make sure, that once the stid is marked revoked, it is not\nremoved by the nfsd4_free_stateid(), the laundromat take a reference\non the stateid. Then, coordinating whether the stid has been put\non the cl_revoked list or we are processing FREE_STATEID and need to\nmake sure to remove it from the list, each check that state and act\naccordingly. If laundromat has added to the cl_revoke list before\nthe arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove\nit from the list. If nfsd4_free_stateid() finds that operations arrived\nbefore laundromat has placed it on cl_revoke list, it marks the state\nfreed and then laundromat will no longer add it to the list.\n\nAlso, for nfsd4_delegreturn() when looking for the specified stid,\nwe need to access stid that are marked removed or freeable, it means\nthe laundromat has started processing it but hasn\u0027t finished and this\ndelegreturn needs to return nfserr_deleg_revoked and not\nnfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the\nlack of it will leave this stid on the cl_revoked list indefinitely."
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2025-05-04T09:46:08.479Z",
            "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "shortName": "Linux"
          },
          "references": [
            {
              "url": "https://git.kernel.org/stable/c/967faa26f313a62e7bebc55d5b8122eaee43b929"
            },
            {
              "url": "https://git.kernel.org/stable/c/8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a"
            }
          ],
          "title": "nfsd: fix race between laundromat and free_stateid",
          "x_generator": {
            "engine": "bippy-1.2.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "assignerShortName": "Linux",
        "cveId": "CVE-2024-50106",
        "datePublished": "2024-11-05T17:10:40.747Z",
        "dateReserved": "2024-10-21T19:36:19.946Z",
        "dateUpdated": "2025-05-04T09:46:08.479Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}



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