CVE-2026-31519 (GCVE-0-2026-31519)
Vulnerability from cvelistv5 – Published: 2026-04-22 13:54 – Updated: 2026-11-05 21:45
VLAI
EPSS
VEX
Title
btrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create
Summary
In the Linux kernel, the following vulnerability has been resolved:
btrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create
We have recently observed a number of subvolumes with broken dentries.
ls-ing the parent dir looks like:
drwxrwxrwt 1 root root 16 Jan 23 16:49 .
drwxr-xr-x 1 root root 24 Jan 23 16:48 ..
d????????? ? ? ? ? ? broken_subvol
and similarly stat-ing the file fails.
In this state, deleting the subvol fails with ENOENT, but attempting to
create a new file or subvol over it errors out with EEXIST and even
aborts the fs. Which leaves us a bit stuck.
dmesg contains a single notable error message reading:
"could not do orphan cleanup -2"
2 is ENOENT and the error comes from the failure handling path of
btrfs_orphan_cleanup(), with the stack leading back up to
btrfs_lookup().
btrfs_lookup
btrfs_lookup_dentry
btrfs_orphan_cleanup // prints that message and returns -ENOENT
After some detailed inspection of the internal state, it became clear
that:
- there are no orphan items for the subvol
- the subvol is otherwise healthy looking, it is not half-deleted or
anything, there is no drop progress, etc.
- the subvol was created a while ago and does the meaningful first
btrfs_orphan_cleanup() call that sets BTRFS_ROOT_ORPHAN_CLEANUP much
later.
- after btrfs_orphan_cleanup() fails, btrfs_lookup_dentry() returns -ENOENT,
which results in a negative dentry for the subvolume via
d_splice_alias(NULL, dentry), leading to the observed behavior. The
bug can be mitigated by dropping the dentry cache, at which point we
can successfully delete the subvolume if we want.
i.e.,
btrfs_lookup()
btrfs_lookup_dentry()
if (!sb_rdonly(inode->vfs_inode)->vfs_inode)
btrfs_orphan_cleanup(sub_root)
test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)
btrfs_search_slot() // finds orphan item for inode N
...
prints "could not do orphan cleanup -2"
if (inode == ERR_PTR(-ENOENT))
inode = NULL;
return d_splice_alias(NULL, dentry) // NEGATIVE DENTRY for valid subvolume
btrfs_orphan_cleanup() does test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)
on the root when it runs, so it cannot run more than once on a given
root, so something else must run concurrently. However, the obvious
routes to deleting an orphan when nlinks goes to 0 should not be able to
run without first doing a lookup into the subvolume, which should run
btrfs_orphan_cleanup() and set the bit.
The final important observation is that create_subvol() calls
d_instantiate_new() but does not set BTRFS_ROOT_ORPHAN_CLEANUP, so if
the dentry cache gets dropped, the next lookup into the subvolume will
make a real call into btrfs_orphan_cleanup() for the first time. This
opens up the possibility of concurrently deleting the inode/orphan items
but most typical evict() paths will be holding a reference on the parent
dentry (child dentry holds parent->d_lockref.count via dget in
d_alloc(), released in __dentry_kill()) and prevent the parent from
being removed from the dentry cache.
The one exception is delayed iputs. Ordered extent creation calls
igrab() on the inode. If the file is unlinked and closed while those
refs are held, iput() in __dentry_kill() decrements i_count but does
not trigger eviction (i_count > 0). The child dentry is freed and the
subvol dentry's d_lockref.count drops to 0, making it evictable while
the inode is still alive.
Since there are two races (the race between writeback and unlink and
the race between lookup and delayed iputs), and there are too many moving
parts, the following three diagrams show the complete picture.
(Only the second and third are races)
Phase 1:
Create Subvol in dentry cache without BTRFS_ROOT_ORPHAN_CLEANUP set
btrfs_mksubvol()
lookup_one_len()
__lookup_slow()
d_alloc_parallel()
__d_alloc() // d_lockref.count = 1
create_subvol(dentry)
// doesn't touch the bit..
d_instantiate_new(dentry, inode) // dentry in cache with d_lockref.c
---truncated---
Severity
No CVSS data available.
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-05 21:36 UTC
Assigner
References
6 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c71bf099abddf3e0fdc27f251ba76fca1461d49a , < d43da8de0ed376abafbad8a245a1835e8f66cb0f
(git)
Affected: c71bf099abddf3e0fdc27f251ba76fca1461d49a , < c57276ced3c3207f42182dfa2f0d8e860357e111 (git) Affected: c71bf099abddf3e0fdc27f251ba76fca1461d49a , < a41a9b8d19a98b45591528c6e54d31cc66271d1e (git) Affected: c71bf099abddf3e0fdc27f251ba76fca1461d49a , < 2ec578e6452138ab76f6c9a9c18711fcd197649f (git) Affected: c71bf099abddf3e0fdc27f251ba76fca1461d49a , < 696683f214495db3cdacab9a713efaaced8660f8 (git) Affected: c71bf099abddf3e0fdc27f251ba76fca1461d49a , < 5131fa077f9bb386a1b901bf5b247041f0ec8f80 (git) Affected: c4ba0bd9db5e8fd2664be0fd4ec01335fe3268eb (git) Affected: 2.6.32.19 , < 2.6.33 (semver) |
guessed | |
| Linux | Linux |
Affected:
2.6.33
Unaffected: 0 , < 2.6.33 (semver) Unaffected: 6.1.168 , ≤ 6.1.* (semver) Unaffected: 6.6.131 , ≤ 6.6.* (semver) Unaffected: 6.12.80 , ≤ 6.12.* (semver) Unaffected: 6.18.21 , ≤ 6.18.* (semver) Unaffected: 6.19.11 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix) |
guessed |
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create\n\nWe have recently observed a number of subvolumes with broken dentries.\nls-ing the parent dir looks like:\n\ndrwxrwxrwt 1 root root 16 Jan 23 16:49 .\ndrwxr-xr-x 1 root root 24 Jan 23 16:48 ..\nd????????? ? ? ? ? ? broken_subvol\n\nand similarly stat-ing the file fails.\n\nIn this state, deleting the subvol fails with ENOENT, but attempting to\ncreate a new file or subvol over it errors out with EEXIST and even\naborts the fs. Which leaves us a bit stuck.\n\ndmesg contains a single notable error message reading:\n\"could not do orphan cleanup -2\"\n\n2 is ENOENT and the error comes from the failure handling path of\nbtrfs_orphan_cleanup(), with the stack leading back up to\nbtrfs_lookup().\n\nbtrfs_lookup\nbtrfs_lookup_dentry\nbtrfs_orphan_cleanup // prints that message and returns -ENOENT\n\nAfter some detailed inspection of the internal state, it became clear\nthat:\n- there are no orphan items for the subvol\n- the subvol is otherwise healthy looking, it is not half-deleted or\n anything, there is no drop progress, etc.\n- the subvol was created a while ago and does the meaningful first\n btrfs_orphan_cleanup() call that sets BTRFS_ROOT_ORPHAN_CLEANUP much\n later.\n- after btrfs_orphan_cleanup() fails, btrfs_lookup_dentry() returns -ENOENT,\n which results in a negative dentry for the subvolume via\n d_splice_alias(NULL, dentry), leading to the observed behavior. The\n bug can be mitigated by dropping the dentry cache, at which point we\n can successfully delete the subvolume if we want.\n\ni.e.,\nbtrfs_lookup()\n btrfs_lookup_dentry()\n if (!sb_rdonly(inode-\u003evfs_inode)-\u003evfs_inode)\n btrfs_orphan_cleanup(sub_root)\n test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\n btrfs_search_slot() // finds orphan item for inode N\n ...\n prints \"could not do orphan cleanup -2\"\n if (inode == ERR_PTR(-ENOENT))\n inode = NULL;\n return d_splice_alias(NULL, dentry) // NEGATIVE DENTRY for valid subvolume\n\nbtrfs_orphan_cleanup() does test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\non the root when it runs, so it cannot run more than once on a given\nroot, so something else must run concurrently. However, the obvious\nroutes to deleting an orphan when nlinks goes to 0 should not be able to\nrun without first doing a lookup into the subvolume, which should run\nbtrfs_orphan_cleanup() and set the bit.\n\nThe final important observation is that create_subvol() calls\nd_instantiate_new() but does not set BTRFS_ROOT_ORPHAN_CLEANUP, so if\nthe dentry cache gets dropped, the next lookup into the subvolume will\nmake a real call into btrfs_orphan_cleanup() for the first time. This\nopens up the possibility of concurrently deleting the inode/orphan items\nbut most typical evict() paths will be holding a reference on the parent\ndentry (child dentry holds parent-\u003ed_lockref.count via dget in\nd_alloc(), released in __dentry_kill()) and prevent the parent from\nbeing removed from the dentry cache.\n\nThe one exception is delayed iputs. Ordered extent creation calls\nigrab() on the inode. If the file is unlinked and closed while those\nrefs are held, iput() in __dentry_kill() decrements i_count but does\nnot trigger eviction (i_count \u003e 0). The child dentry is freed and the\nsubvol dentry\u0027s d_lockref.count drops to 0, making it evictable while\nthe inode is still alive.\n\nSince there are two races (the race between writeback and unlink and\nthe race between lookup and delayed iputs), and there are too many moving\nparts, the following three diagrams show the complete picture.\n(Only the second and third are races)\n\nPhase 1:\nCreate Subvol in dentry cache without BTRFS_ROOT_ORPHAN_CLEANUP set\n\nbtrfs_mksubvol()\n lookup_one_len()\n __lookup_slow()\n d_alloc_parallel()\n __d_alloc() // d_lockref.count = 1\n create_subvol(dentry)\n // doesn\u0027t touch the bit..\n d_instantiate_new(dentry, inode) // dentry in cache with d_lockref.c\n---truncated---"
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create\n\nWe have recently observed a number of subvolumes with broken dentries.\nls-ing the parent dir looks like:\n\ndrwxrwxrwt 1 root root 16 Jan 23 16:49 .\ndrwxr-xr-x 1 root root 24 Jan 23 16:48 ..\nd????????? ? ? ? ? ? broken_subvol\n\nand similarly stat-ing the file fails.\n\nIn this state, deleting the subvol fails with ENOENT, but attempting to\ncreate a new file or subvol over it errors out with EEXIST and even\naborts the fs. Which leaves us a bit stuck.\n\ndmesg contains a single notable error message reading:\n\"could not do orphan cleanup -2\"\n\n2 is ENOENT and the error comes from the failure handling path of\nbtrfs_orphan_cleanup(), with the stack leading back up to\nbtrfs_lookup().\n\nbtrfs_lookup\nbtrfs_lookup_dentry\nbtrfs_orphan_cleanup // prints that message and returns -ENOENT\n\nAfter some detailed inspection of the internal state, it became clear\nthat:\n- there are no orphan items for the subvol\n- the subvol is otherwise healthy looking, it is not half-deleted or\n anything, there is no drop progress, etc.\n- the subvol was created a while ago and does the meaningful first\n btrfs_orphan_cleanup() call that sets BTRFS_ROOT_ORPHAN_CLEANUP much\n later.\n- after btrfs_orphan_cleanup() fails, btrfs_lookup_dentry() returns -ENOENT,\n which results in a negative dentry for the subvolume via\n d_splice_alias(NULL, dentry), leading to the observed behavior. The\n bug can be mitigated by dropping the dentry cache, at which point we\n can successfully delete the subvolume if we want.\n\ni.e.,\nbtrfs_lookup()\n btrfs_lookup_dentry()\n if (!sb_rdonly(inode-\u003evfs_inode)-\u003evfs_inode)\n btrfs_orphan_cleanup(sub_root)\n test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\n btrfs_search_slot() // finds orphan item for inode N\n ...\n prints \"could not do orphan cleanup -2\"\n if (inode == ERR_PTR(-ENOENT))\n inode = NULL;\n return d_splice_alias(NULL, dentry) // NEGATIVE DENTRY for valid subvolume\n\nbtrfs_orphan_cleanup() does test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\non the root when it runs, so it cannot run more than once on a given\nroot, so something else must run concurrently. However, the obvious\nroutes to deleting an orphan when nlinks goes to 0 should not be able to\nrun without first doing a lookup into the subvolume, which should run\nbtrfs_orphan_cleanup() and set the bit.\n\nThe final important observation is that create_subvol() calls\nd_instantiate_new() but does not set BTRFS_ROOT_ORPHAN_CLEANUP, so if\nthe dentry cache gets dropped, the next lookup into the subvolume will\nmake a real call into btrfs_orphan_cleanup() for the first time. This\nopens up the possibility of concurrently deleting the inode/orphan items\nbut most typical evict() paths will be holding a reference on the parent\ndentry (child dentry holds parent-\u003ed_lockref.count via dget in\nd_alloc(), released in __dentry_kill()) and prevent the parent from\nbeing removed from the dentry cache.\n\nThe one exception is delayed iputs. Ordered extent creation calls\nigrab() on the inode. If the file is unlinked and closed while those\nrefs are held, iput() in __dentry_kill() decrements i_count but does\nnot trigger eviction (i_count \u003e 0). The child dentry is freed and the\nsubvol dentry\u0027s d_lockref.count drops to 0, making it evictable while\nthe inode is still alive.\n\nSince there are two races (the race between writeback and unlink and\nthe race between lookup and delayed iputs), and there are too many moving\nparts, the following three diagrams show the complete picture.\n(Only the second and third are races)\n\nPhase 1:\nCreate Subvol in dentry cache without BTRFS_ROOT_ORPHAN_CLEANUP set\n\nbtrfs_mksubvol()\n lookup_one_len()\n __lookup_slow()\n d_alloc_parallel()\n __d_alloc() // d_lockref.count = 1\n create_subvol(dentry)\n // doesn\u0027t touch the bit..\n d_instantiate_new(dentry, inode) // dentry in cache with d_lockref.c\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: btrfs: establecer BTRFS_ROOT_ORPHAN_CLEANUP durante la creaci\u00f3n de un subvolumen Hemos observado recientemente varios subvol\u00famenes con dentries rotos.\nAl ejecutar \u2019ls\u2019 en el directorio padre, se ve as\u00ed: drwxrwxrwt 1 root root 16 Jan 23 16:49 .\ndrwxr-xr-x 1 root root 24 Jan 23 16:48 ..\nd????????? ? ? ? ? ? broken_subvol y de manera similar, la operaci\u00f3n \u2019stat\u2019 sobre el archivo falla. En este estado, eliminar el subvolumen falla con ENOENT, pero intentar crear un nuevo archivo o subvolumen sobre \u00e9l produce un error con EEXIST e incluso aborta el sistema de archivos (fs). Lo que nos deja un poco atascados. dmesg contiene un \u00fanico mensaje de error notable que dice:\n\u2019could not do orphan cleanup -2\u2019 2 es ENOENT y el error proviene de la ruta de manejo de fallos de btrfs_orphan_cleanup(), con la pila de llamadas remont\u00e1ndose hasta btrfs_lookup(). btrfs_lookup\nbtrfs_lookup_dentry\nbtrfs_orphan_cleanup // imprime ese mensaje y devuelve -ENOENT Despu\u00e9s de una inspecci\u00f3n detallada del estado interno, qued\u00f3 claro que:\n- no hay elementos hu\u00e9rfanos para el subvolumen\n- el subvolumen, por lo dem\u00e1s, parece saludable, no est\u00e1 medio eliminado ni nada por el estilo, no hay progreso de eliminaci\u00f3n, etc.\n- el subvolumen fue creado hace un tiempo y realiza la primera llamada significativa a btrfs_orphan_cleanup() que establece BTRFS_ROOT_ORPHAN_CLEANUP mucho m\u00e1s tarde.\n- despu\u00e9s de que btrfs_orphan_cleanup() falla, btrfs_lookup_dentry() devuelve -ENOENT, lo que resulta en un dentry negativo para el subvolumen a trav\u00e9s de d_splice_alias(NULL, dentry), lo que lleva al comportamiento observado. El error puede mitigarse eliminando la cach\u00e9 de dentries, momento en el que podemos eliminar exitosamente el subvolumen si lo deseamos. Es decir,\nbtrfs_lookup() btrfs_lookup_dentry() if (!sb_rdonly(inode-mayor que vfs_inode)-mayor que vfs_inode) btrfs_orphan_cleanup(sub_root) test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP) btrfs_search_slot() // encuentra el elemento hu\u00e9rfano para el inodo N ... imprime \u2019could not do orphan cleanup -2\u2019 if (inode == ERR_PTR(-ENOENT)) inode = NULL; return d_splice_alias(NULL, dentry) // DENTRY NEGATIVO para un subvolumen v\u00e1lido btrfs_orphan_cleanup() ejecuta test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP) en la ra\u00edz cuando se ejecuta, por lo que no puede ejecutarse m\u00e1s de una vez en una ra\u00edz determinada, por lo que algo m\u00e1s debe ejecutarse concurrentemente. Sin embargo, las rutas obvias para eliminar un hu\u00e9rfano cuando nlinks llega a 0 no deber\u00edan poder ejecutarse sin antes realizar una b\u00fasqueda en el subvolumen, lo que deber\u00eda ejecutar btrfs_orphan_cleanup() y establecer el bit. La \u00faltima observaci\u00f3n importante es que create_subvol() llama a d_instantiate_new() pero no establece BTRFS_ROOT_ORPHAN_CLEANUP, por lo que si la cach\u00e9 de dentries se elimina, la siguiente b\u00fasqueda en el subvolumen realizar\u00e1 una llamada real a btrfs_orphan_cleanup() por primera vez. Esto abre la posibilidad de eliminar concurrentemente los elementos inodo/hu\u00e9rfano, pero la mayor\u00eda de las rutas t\u00edpicas de evict() mantendr\u00e1n una referencia al dentry padre (el dentry hijo mantiene parent -\u003e d_lockref.count a trav\u00e9s de dget en d_alloc(), liberado en __dentry_kill()) y evitar\u00e1n que el padre sea eliminado de la cach\u00e9 de dentries. La \u00fanica excepci\u00f3n son los iputs retrasados. La creaci\u00f3n ordenada de extensiones llama a igrab() en el inodo. Si el archivo se desvincula y se cierra mientras se mantienen esas referencias, iput() en __dentry_kill() decrementa i_count pero no activa la expulsi\u00f3n (i_count mayor que 0). El dentry hijo se libera y d_lockref.count del dentry del subvolumen cae a 0, haci\u00e9ndolo expulsable mientras el inodo a\u00fan est\u00e1 vivo. Dado que hay dos condiciones de carrera (la condici\u00f3n de carrera entre writeback y unlink y la condici\u00f3n de carrera entre lookup e iputs retrasados), y hay demasiadas partes m\u00f3viles, los siguientes tres diagramas muestran el panorama completo.\n(Solo la segunda y la tercera son --TRUNCADO--"
}
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"id": "CVE-2026-31519",
"lastModified": "2026-11-11T23:10:00.263",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create\n\nWe have recently observed a number of subvolumes with broken dentries.\nls-ing the parent dir looks like:\n\ndrwxrwxrwt 1 root root 16 Jan 23 16:49 .\ndrwxr-xr-x 1 root root 24 Jan 23 16:48 ..\nd????????? ? ? ? ? ? broken_subvol\n\nand similarly stat-ing the file fails.\n\nIn this state, deleting the subvol fails with ENOENT, but attempting to\ncreate a new file or subvol over it errors out with EEXIST and even\naborts the fs. Which leaves us a bit stuck.\n\ndmesg contains a single notable error message reading:\n\"could not do orphan cleanup -2\"\n\n2 is ENOENT and the error comes from the failure handling path of\nbtrfs_orphan_cleanup(), with the stack leading back up to\nbtrfs_lookup().\n\nbtrfs_lookup\nbtrfs_lookup_dentry\nbtrfs_orphan_cleanup // prints that message and returns -ENOENT\n\nAfter some detailed inspection of the internal state, it became clear\nthat:\n- there are no orphan items for the subvol\n- the subvol is otherwise healthy looking, it is not half-deleted or\n anything, there is no drop progress, etc.\n- the subvol was created a while ago and does the meaningful first\n btrfs_orphan_cleanup() call that sets BTRFS_ROOT_ORPHAN_CLEANUP much\n later.\n- after btrfs_orphan_cleanup() fails, btrfs_lookup_dentry() returns -ENOENT,\n which results in a negative dentry for the subvolume via\n d_splice_alias(NULL, dentry), leading to the observed behavior. The\n bug can be mitigated by dropping the dentry cache, at which point we\n can successfully delete the subvolume if we want.\n\ni.e.,\nbtrfs_lookup()\n btrfs_lookup_dentry()\n if (!sb_rdonly(inode-\u003evfs_inode)-\u003evfs_inode)\n btrfs_orphan_cleanup(sub_root)\n test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\n btrfs_search_slot() // finds orphan item for inode N\n ...\n prints \"could not do orphan cleanup -2\"\n if (inode == ERR_PTR(-ENOENT))\n inode = NULL;\n return d_splice_alias(NULL, dentry) // NEGATIVE DENTRY for valid subvolume\n\nbtrfs_orphan_cleanup() does test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP)\non the root when it runs, so it cannot run more than once on a given\nroot, so something else must run concurrently. However, the obvious\nroutes to deleting an orphan when nlinks goes to 0 should not be able to\nrun without first doing a lookup into the subvolume, which should run\nbtrfs_orphan_cleanup() and set the bit.\n\nThe final important observation is that create_subvol() calls\nd_instantiate_new() but does not set BTRFS_ROOT_ORPHAN_CLEANUP, so if\nthe dentry cache gets dropped, the next lookup into the subvolume will\nmake a real call into btrfs_orphan_cleanup() for the first time. This\nopens up the possibility of concurrently deleting the inode/orphan items\nbut most typical evict() paths will be holding a reference on the parent\ndentry (child dentry holds parent-\u003ed_lockref.count via dget in\nd_alloc(), released in __dentry_kill()) and prevent the parent from\nbeing removed from the dentry cache.\n\nThe one exception is delayed iputs. Ordered extent creation calls\nigrab() on the inode. If the file is unlinked and closed while those\nrefs are held, iput() in __dentry_kill() decrements i_count but does\nnot trigger eviction (i_count \u003e 0). The child dentry is freed and the\nsubvol dentry\u0027s d_lockref.count drops to 0, making it evictable while\nthe inode is still alive.\n\nSince there are two races (the race between writeback and unlink and\nthe race between lookup and delayed iputs), and there are too many moving\nparts, the following three diagrams show the complete picture.\n(Only the second and third are races)\n\nPhase 1:\nCreate Subvol in dentry cache without BTRFS_ROOT_ORPHAN_CLEANUP set\n\nbtrfs_mksubvol()\n lookup_one_len()\n __lookup_slow()\n d_alloc_parallel()\n __d_alloc() // d_lockref.count = 1\n create_subvol(dentry)\n // doesn\u0027t touch the bit..\n d_instantiate_new(dentry, inode) // dentry in cache with d_lockref.c\n---truncated---"
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},
{
"url": "https://git.kernel.org/stable/c/696683f214495db3cdacab9a713efaaced8660f8"
},
{
"url": "https://git.kernel.org/stable/c/5131fa077f9bb386a1b901bf5b247041f0ec8f80"
}
],
"title": "btrfs: set BTRFS_ROOT_ORPHAN_CLEANUP during subvol create",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-31519",
"datePublished": "2026-04-22T13:54:34.860Z",
"dateReserved": "2026-03-09T15:48:24.108Z",
"dateUpdated": "2026-11-05T21:45:04.959Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
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Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.