fkie_cve-2022-50478
Vulnerability from fkie_nvd
Published
2025-10-04 16:15
Modified
2025-10-06 14:56
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset()
Patch series "nilfs2: fix UBSAN shift-out-of-bounds warnings on mount
time".
The first patch fixes a bug reported by syzbot, and the second one fixes
the remaining bug of the same kind. Although they are triggered by the
same super block data anomaly, I divided it into the above two because the
details of the issues and how to fix it are different.
Both are required to eliminate the shift-out-of-bounds issues at mount
time.
This patch (of 2):
If the block size exponent information written in an on-disk superblock is
corrupted, nilfs_sb2_bad_offset helper function can trigger
shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn
is set):
shift exponent 38983 is too large for 64-bit type 'unsigned long long'
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline]
nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523
init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577
nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047
nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317
...
In addition, since nilfs_sb2_bad_offset() performs multiplication without
considering the upper bound, the computation may overflow if the disk
layout parameters are not normal.
This fixes these issues by inserting preliminary sanity checks for those
parameters and by converting the comparison from one involving
multiplication and left bit-shifting to one using division and right
bit-shifting.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset()\n\nPatch series \"nilfs2: fix UBSAN shift-out-of-bounds warnings on mount\ntime\".\n\nThe first patch fixes a bug reported by syzbot, and the second one fixes\nthe remaining bug of the same kind. Although they are triggered by the\nsame super block data anomaly, I divided it into the above two because the\ndetails of the issues and how to fix it are different.\n\nBoth are required to eliminate the shift-out-of-bounds issues at mount\ntime.\n\n\nThis patch (of 2):\n\nIf the block size exponent information written in an on-disk superblock is\ncorrupted, nilfs_sb2_bad_offset helper function can trigger\nshift-out-of-bounds warning followed by a kernel panic (if panic_on_warn\nis set):\n\n shift exponent 38983 is too large for 64-bit type \u0027unsigned long long\u0027\n Call Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106\n ubsan_epilogue lib/ubsan.c:151 [inline]\n __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322\n nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline]\n nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523\n init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577\n nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047\n nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317\n ...\n\nIn addition, since nilfs_sb2_bad_offset() performs multiplication without\nconsidering the upper bound, the computation may overflow if the disk\nlayout parameters are not normal.\n\nThis fixes these issues by inserting preliminary sanity checks for those\nparameters and by converting the comparison from one involving\nmultiplication and left bit-shifting to one using division and right\nbit-shifting."
}
],
"id": "CVE-2022-50478",
"lastModified": "2025-10-06T14:56:47.823",
"metrics": {},
"published": "2025-10-04T16:15:44.417",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1012ff77284e3bec0ec0a35a820b03ec43dec2cc"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/610a2a3d7d8be3537458a378ec69396a76c385b6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/62d11ec205ef14d8acf172cfc9904fdbf200025a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6b0ea3df56cccd53398d0289f399f19d43136b2e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9b3ba54025357440d6c4414c670984f628c6f6bf"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a6f89b10042baca218c8598d6db5a44c7e32625f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b47f5c579c8186f7f5ab5e4254e0734ea5b7bf7a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d464b035c0613856d012cf1704879d3ff3f057fb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d706485dffbbbf848e681edda29c7a46ac55698c"
}
],
"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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