CVE-2026-43288 (GCVE-0-2026-43288)
Vulnerability from cvelistv5 – Published: 2026-05-08 13:11 – Updated: 2026-05-09 04:09
VLAI?
Title
ext4: move ext4_percpu_param_init() before ext4_mb_init()
Summary
In the Linux kernel, the following vulnerability has been resolved:
ext4: move ext4_percpu_param_init() before ext4_mb_init()
When running `kvm-xfstests -c ext4/1k -C 1 generic/383` with the
`DOUBLE_CHECK` macro defined, the following panic is triggered:
==================================================================
EXT4-fs error (device vdc): ext4_validate_block_bitmap:423:
comm mount: bg 0: bad block bitmap checksum
BUG: unable to handle page fault for address: ff110000fa2cc000
PGD 3e01067 P4D 3e02067 PUD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 2386 Comm: mount Tainted: G W
6.18.0-gba65a4e7120a-dirty #1152 PREEMPT(none)
RIP: 0010:percpu_counter_add_batch+0x13/0xa0
Call Trace:
<TASK>
ext4_mark_group_bitmap_corrupted+0xcb/0xe0
ext4_validate_block_bitmap+0x2a1/0x2f0
ext4_read_block_bitmap+0x33/0x50
mb_group_bb_bitmap_alloc+0x33/0x80
ext4_mb_add_groupinfo+0x190/0x250
ext4_mb_init_backend+0x87/0x290
ext4_mb_init+0x456/0x640
__ext4_fill_super+0x1072/0x1680
ext4_fill_super+0xd3/0x280
get_tree_bdev_flags+0x132/0x1d0
vfs_get_tree+0x29/0xd0
vfs_cmd_create+0x59/0xe0
__do_sys_fsconfig+0x4f6/0x6b0
do_syscall_64+0x50/0x1f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================
This issue can be reproduced using the following commands:
mkfs.ext4 -F -q -b 1024 /dev/sda 5G
tune2fs -O quota,project /dev/sda
mount /dev/sda /tmp/test
With DOUBLE_CHECK defined, mb_group_bb_bitmap_alloc() reads
and validates the block bitmap. When the validation fails,
ext4_mark_group_bitmap_corrupted() attempts to update
sbi->s_freeclusters_counter. However, this percpu_counter has not been
initialized yet at this point, which leads to the panic described above.
Fix this by moving the execution of ext4_percpu_param_init() to occur
before ext4_mb_init(), ensuring the per-CPU counters are initialized
before they are used.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Affected:
d5e03cbb0c88cd1be39f2adc37d602230045964b , < 0d5fcb063cdabb9aeaa8554b7fedad2092c4150e
(git)
Affected: d5e03cbb0c88cd1be39f2adc37d602230045964b , < 9e9fb259bcddf459a0168f4a964e979e500a68a5 (git) Affected: d5e03cbb0c88cd1be39f2adc37d602230045964b , < bf5b609524497c195f801cd5707252384aed8149 (git) Affected: d5e03cbb0c88cd1be39f2adc37d602230045964b , < aec095f3cc6cf209effd93278ce35be27db81d73 (git) Affected: d5e03cbb0c88cd1be39f2adc37d602230045964b , < 270564513489d98b721a1e4a10017978d5213bff (git) |
||
{
"containers": {
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"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ext4/super.c"
],
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"vendor": "Linux",
"versions": [
{
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"version": "d5e03cbb0c88cd1be39f2adc37d602230045964b",
"versionType": "git"
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{
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"versionType": "git"
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{
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"status": "affected",
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"versionType": "git"
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{
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{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.17"
},
{
"lessThan": "3.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.128",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.75",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.16",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "3.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.75",
"versionStartIncluding": "3.17",
"vulnerable": true
},
{
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"versionEndExcluding": "6.18.16",
"versionStartIncluding": "3.17",
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},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.6",
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"vulnerable": true
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: move ext4_percpu_param_init() before ext4_mb_init()\n\nWhen running `kvm-xfstests -c ext4/1k -C 1 generic/383` with the\n`DOUBLE_CHECK` macro defined, the following panic is triggered:\n\n==================================================================\nEXT4-fs error (device vdc): ext4_validate_block_bitmap:423:\n comm mount: bg 0: bad block bitmap checksum\nBUG: unable to handle page fault for address: ff110000fa2cc000\nPGD 3e01067 P4D 3e02067 PUD 0\nOops: Oops: 0000 [#1] SMP NOPTI\nCPU: 0 UID: 0 PID: 2386 Comm: mount Tainted: G W\n 6.18.0-gba65a4e7120a-dirty #1152 PREEMPT(none)\nRIP: 0010:percpu_counter_add_batch+0x13/0xa0\nCall Trace:\n \u003cTASK\u003e\n ext4_mark_group_bitmap_corrupted+0xcb/0xe0\n ext4_validate_block_bitmap+0x2a1/0x2f0\n ext4_read_block_bitmap+0x33/0x50\n mb_group_bb_bitmap_alloc+0x33/0x80\n ext4_mb_add_groupinfo+0x190/0x250\n ext4_mb_init_backend+0x87/0x290\n ext4_mb_init+0x456/0x640\n __ext4_fill_super+0x1072/0x1680\n ext4_fill_super+0xd3/0x280\n get_tree_bdev_flags+0x132/0x1d0\n vfs_get_tree+0x29/0xd0\n vfs_cmd_create+0x59/0xe0\n __do_sys_fsconfig+0x4f6/0x6b0\n do_syscall_64+0x50/0x1f0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n==================================================================\n\nThis issue can be reproduced using the following commands:\n mkfs.ext4 -F -q -b 1024 /dev/sda 5G\n tune2fs -O quota,project /dev/sda\n mount /dev/sda /tmp/test\n\nWith DOUBLE_CHECK defined, mb_group_bb_bitmap_alloc() reads\nand validates the block bitmap. When the validation fails,\next4_mark_group_bitmap_corrupted() attempts to update\nsbi-\u003es_freeclusters_counter. However, this percpu_counter has not been\ninitialized yet at this point, which leads to the panic described above.\n\nFix this by moving the execution of ext4_percpu_param_init() to occur\nbefore ext4_mb_init(), ensuring the per-CPU counters are initialized\nbefore they are used."
}
],
"providerMetadata": {
"dateUpdated": "2026-05-09T04:09:57.796Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/0d5fcb063cdabb9aeaa8554b7fedad2092c4150e"
},
{
"url": "https://git.kernel.org/stable/c/9e9fb259bcddf459a0168f4a964e979e500a68a5"
},
{
"url": "https://git.kernel.org/stable/c/bf5b609524497c195f801cd5707252384aed8149"
},
{
"url": "https://git.kernel.org/stable/c/aec095f3cc6cf209effd93278ce35be27db81d73"
},
{
"url": "https://git.kernel.org/stable/c/270564513489d98b721a1e4a10017978d5213bff"
}
],
"title": "ext4: move ext4_percpu_param_init() before ext4_mb_init()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-43288",
"datePublished": "2026-05-08T13:11:13.195Z",
"dateReserved": "2026-05-01T14:12:55.999Z",
"dateUpdated": "2026-05-09T04:09:57.796Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-43288\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-08T14:16:35.737\",\"lastModified\":\"2026-05-08T14:16:35.737\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\next4: move ext4_percpu_param_init() before ext4_mb_init()\\n\\nWhen running `kvm-xfstests -c ext4/1k -C 1 generic/383` with the\\n`DOUBLE_CHECK` macro defined, the following panic is triggered:\\n\\n==================================================================\\nEXT4-fs error (device vdc): ext4_validate_block_bitmap:423:\\n comm mount: bg 0: bad block bitmap checksum\\nBUG: unable to handle page fault for address: ff110000fa2cc000\\nPGD 3e01067 P4D 3e02067 PUD 0\\nOops: Oops: 0000 [#1] SMP NOPTI\\nCPU: 0 UID: 0 PID: 2386 Comm: mount Tainted: G W\\n 6.18.0-gba65a4e7120a-dirty #1152 PREEMPT(none)\\nRIP: 0010:percpu_counter_add_batch+0x13/0xa0\\nCall Trace:\\n \u003cTASK\u003e\\n ext4_mark_group_bitmap_corrupted+0xcb/0xe0\\n ext4_validate_block_bitmap+0x2a1/0x2f0\\n ext4_read_block_bitmap+0x33/0x50\\n mb_group_bb_bitmap_alloc+0x33/0x80\\n ext4_mb_add_groupinfo+0x190/0x250\\n ext4_mb_init_backend+0x87/0x290\\n ext4_mb_init+0x456/0x640\\n __ext4_fill_super+0x1072/0x1680\\n ext4_fill_super+0xd3/0x280\\n get_tree_bdev_flags+0x132/0x1d0\\n vfs_get_tree+0x29/0xd0\\n vfs_cmd_create+0x59/0xe0\\n __do_sys_fsconfig+0x4f6/0x6b0\\n do_syscall_64+0x50/0x1f0\\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n==================================================================\\n\\nThis issue can be reproduced using the following commands:\\n mkfs.ext4 -F -q -b 1024 /dev/sda 5G\\n tune2fs -O quota,project /dev/sda\\n mount /dev/sda /tmp/test\\n\\nWith DOUBLE_CHECK defined, mb_group_bb_bitmap_alloc() reads\\nand validates the block bitmap. When the validation fails,\\next4_mark_group_bitmap_corrupted() attempts to update\\nsbi-\u003es_freeclusters_counter. However, this percpu_counter has not been\\ninitialized yet at this point, which leads to the panic described above.\\n\\nFix this by moving the execution of ext4_percpu_param_init() to occur\\nbefore ext4_mb_init(), ensuring the per-CPU counters are initialized\\nbefore they are used.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0d5fcb063cdabb9aeaa8554b7fedad2092c4150e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/270564513489d98b721a1e4a10017978d5213bff\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9e9fb259bcddf459a0168f4a964e979e500a68a5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/aec095f3cc6cf209effd93278ce35be27db81d73\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bf5b609524497c195f801cd5707252384aed8149\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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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.
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