fkie_cve-2025-40150
Vulnerability from fkie_nvd
Published
2025-11-12 11:15
Modified
2025-11-12 16:19
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid migrating empty section
It reports a bug from device w/ zufs:
F2FS-fs (dm-64): Inconsistent segment (173822) type [1, 0] in SSA and SIT
F2FS-fs (dm-64): Stopped filesystem due to reason: 4
Thread A Thread B
- f2fs_expand_inode_data
- f2fs_allocate_pinning_section
- f2fs_gc_range
- do_garbage_collect w/ segno #x
- writepage
- f2fs_allocate_data_block
- new_curseg
- allocate segno #x
The root cause is: fallocate on pinning file may race w/ block allocation
as above, result in do_garbage_collect() from fallocate() may migrate
segment which is just allocated by a log, the log will update segment type
in its in-memory structure, however GC will get segment type from on-disk
SSA block, once segment type changes by log, we can detect such
inconsistency, then shutdown filesystem.
In this case, on-disk SSA shows type of segno #173822 is 1 (SUM_TYPE_NODE),
however segno #173822 was just allocated as data type segment, so in-memory
SIT shows type of segno #173822 is 0 (SUM_TYPE_DATA).
Change as below to fix this issue:
- check whether current section is empty before gc
- add sanity checks on do_garbage_collect() to avoid any race case, result
in migrating segment used by log.
- btw, it fixes misc issue in printed logs: "SSA and SIT" -> "SIT and SSA".
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid migrating empty section\n\nIt reports a bug from device w/ zufs:\n\nF2FS-fs (dm-64): Inconsistent segment (173822) type [1, 0] in SSA and SIT\nF2FS-fs (dm-64): Stopped filesystem due to reason: 4\n\nThread A\t\t\t\tThread B\n- f2fs_expand_inode_data\n - f2fs_allocate_pinning_section\n - f2fs_gc_range\n - do_garbage_collect w/ segno #x\n\t\t\t\t\t- writepage\n\t\t\t\t\t - f2fs_allocate_data_block\n\t\t\t\t\t - new_curseg\n\t\t\t\t\t - allocate segno #x\n\nThe root cause is: fallocate on pinning file may race w/ block allocation\nas above, result in do_garbage_collect() from fallocate() may migrate\nsegment which is just allocated by a log, the log will update segment type\nin its in-memory structure, however GC will get segment type from on-disk\nSSA block, once segment type changes by log, we can detect such\ninconsistency, then shutdown filesystem.\n\nIn this case, on-disk SSA shows type of segno #173822 is 1 (SUM_TYPE_NODE),\nhowever segno #173822 was just allocated as data type segment, so in-memory\nSIT shows type of segno #173822 is 0 (SUM_TYPE_DATA).\n\nChange as below to fix this issue:\n- check whether current section is empty before gc\n- add sanity checks on do_garbage_collect() to avoid any race case, result\nin migrating segment used by log.\n- btw, it fixes misc issue in printed logs: \"SSA and SIT\" -\u003e \"SIT and SSA\"."
}
],
"id": "CVE-2025-40150",
"lastModified": "2025-11-12T16:19:12.850",
"metrics": {},
"published": "2025-11-12T11:15:44.923",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d625a2b08c089397d3a03bff13fa8645e4ec7a01"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/eec1589be36fcf7440755703e4faeee2c01e360b"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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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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