In the Linux kernel, the following vulnerability has been resolved:
nilfs2: Fix potential block overflow that cause system hang
When a user executes the FITRIM command, an underflow can occur when
calculating nblocks if end_block is too small. Since nblocks is of
type sector_t, which is u64, a negative nblocks value will become a
very large positive integer. This ultimately leads to the block layer
function __blkdev_issue_discard() taking an excessively long time to
process the bio chain, and the ns_segctor_sem lock remains held for a
long period. This prevents other tasks from acquiring the ns_segctor_sem
lock, resulting in the hang reported by syzbot in [1].
If the ending block is too small, typically if it is smaller than 4KiB
range, depending on the usage of the segment 0, it may be possible to
attempt a discard request beyond the device size causing the hang.
Exiting successfully and assign the discarded size (0 in this case)
to range->len.
Although the start and len values in the user input range are too small,
a conservative strategy is adopted here to safely ignore them, which is
equivalent to a no-op; it will not perform any trimming and will not
throw an error.
[1]
task:segctord state:D stack:28968 pid:6093 tgid:6093 ppid:2 task_flags:0x200040 flags:0x00080000
Call Trace:
rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272
nilfs_transaction_lock+0x253/0x4c0 fs/nilfs2/segment.c:357
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline]
nilfs_segctor_thread+0x6ec/0xe00 fs/nilfs2/segment.c:2684
[ryusuke: corrected part of the commit message about the consequences]
nilfs2: Fix potential block overflow that cause system hang
When a user executes the FITRIM command, an underflow can occur when
calculating nblocks if end_block is too small. Since nblocks is of
type sector_t, which is u64, a negative nblocks value will become a
very large positive integer. This ultimately leads to the block layer
function __blkdev_issue_discard() taking an excessively long time to
process the bio chain, and the ns_segctor_sem lock remains held for a
long period. This prevents other tasks from acquiring the ns_segctor_sem
lock, resulting in the hang reported by syzbot in [1].
If the ending block is too small, typically if it is smaller than 4KiB
range, depending on the usage of the segment 0, it may be possible to
attempt a discard request beyond the device size causing the hang.
Exiting successfully and assign the discarded size (0 in this case)
to range->len.
Although the start and len values in the user input range are too small,
a conservative strategy is adopted here to safely ignore them, which is
equivalent to a no-op; it will not perform any trimming and will not
throw an error.
[1]
task:segctord state:D stack:28968 pid:6093 tgid:6093 ppid:2 task_flags:0x200040 flags:0x00080000
Call Trace:
rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272
nilfs_transaction_lock+0x253/0x4c0 fs/nilfs2/segment.c:357
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline]
nilfs_segctor_thread+0x6ec/0xe00 fs/nilfs2/segment.c:2684
[ryusuke: corrected part of the commit message about the consequences]
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
Configuration 1 [-]
|
No data.
| Vendor | Product | Confidence | Versions |
|---|---|---|---|
| Linux | Linux Kernel | — | — |
Found an issue or want to improve our Enrichment? You can suggest it directly by opening an issue on our dedicated GitHub repository .
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
 Debian DLA |
DLA-4498-1 | linux security update |
| Debian DLA |
DLA-4499-1 | linux-6.1 security update |
 Debian DSA |
DSA-6141-1 | linux security update |
| Debian DSA |
DSA-6163-1 | linux security update |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 18 Mar 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | NVD-CWE-noinfo | |
| Metrics |
cvssV3_1
|
Mon, 23 Feb 2026 03:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Thu, 19 Feb 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Thu, 19 Feb 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Wed, 18 Feb 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: nilfs2: Fix potential block overflow that cause system hang When a user executes the FITRIM command, an underflow can occur when calculating nblocks if end_block is too small. Since nblocks is of type sector_t, which is u64, a negative nblocks value will become a very large positive integer. This ultimately leads to the block layer function __blkdev_issue_discard() taking an excessively long time to process the bio chain, and the ns_segctor_sem lock remains held for a long period. This prevents other tasks from acquiring the ns_segctor_sem lock, resulting in the hang reported by syzbot in [1]. If the ending block is too small, typically if it is smaller than 4KiB range, depending on the usage of the segment 0, it may be possible to attempt a discard request beyond the device size causing the hang. Exiting successfully and assign the discarded size (0 in this case) to range->len. Although the start and len values in the user input range are too small, a conservative strategy is adopted here to safely ignore them, which is equivalent to a no-op; it will not perform any trimming and will not throw an error. [1] task:segctord state:D stack:28968 pid:6093 tgid:6093 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272 nilfs_transaction_lock+0x253/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline] nilfs_segctor_thread+0x6ec/0xe00 fs/nilfs2/segment.c:2684 [ryusuke: corrected part of the commit message about the consequences] | |
| Title | nilfs2: Fix potential block overflow that cause system hang | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-02-23T03:16:22.003Z
Reserved: 2026-02-18T14:25:13.845Z
Link: CVE-2025-71237
Vulnrichment
No data.
NVD
Status : Analyzed
Published: 2026-02-18T16:22:30.517
Modified: 2026-03-18T14:58:45.933
Link: CVE-2025-71237
Redhat
OpenCVE Enrichment
Updated: 2026-02-19T10:11:51Z
Weaknesses