Description
In the Linux kernel, the following vulnerability has been resolved:
fsnotify: prevent mark additions during connector teardown
fsnotify_destroy_marks() keeps a reference to its current mark while it
drops conn->lock to destroy the mark. This stabilizes the forward-walk
cursor, but does not prevent a new mark from being inserted before it.
For example, an inotify watch re-added after IN_IGNORED sorts before the
old, detached mark for the same group. The walk can miss the replacement
and then detach the entire connector from the object.
The replacement is still on its group's marks_list and, for inotify, in
the watch IDR. The group mutex no longer protects the connector's object
from disappearing. An unprivileged fdinfo read racing the final detach
can consequently call igrab(NULL):
BUG: KASAN: null-ptr-deref in igrab+0x24/0x100
Write of size 4 at addr 0000000000000148
Call Trace:
igrab+0x24/0x100
inotify_show_fdinfo+0x1dc/0x5e0
seq_show+0x397/0x690
Set a DESTROYING flag under conn->lock before starting the walk, and
reject new marks on that connector with -ENOENT. The existing add-mark
error paths undo the temporary group-list entry and the backend's watch
allocation. Do not wait for teardown while holding the group mutex,
which the destroyer needs. Once the old connector is detached, an add
can install a fresh connector as before.
This closes the insertion race for all object types using the common
connector teardown, without changing the mark reference or SRCU lifetime
rules.
fsnotify: prevent mark additions during connector teardown
fsnotify_destroy_marks() keeps a reference to its current mark while it
drops conn->lock to destroy the mark. This stabilizes the forward-walk
cursor, but does not prevent a new mark from being inserted before it.
For example, an inotify watch re-added after IN_IGNORED sorts before the
old, detached mark for the same group. The walk can miss the replacement
and then detach the entire connector from the object.
The replacement is still on its group's marks_list and, for inotify, in
the watch IDR. The group mutex no longer protects the connector's object
from disappearing. An unprivileged fdinfo read racing the final detach
can consequently call igrab(NULL):
BUG: KASAN: null-ptr-deref in igrab+0x24/0x100
Write of size 4 at addr 0000000000000148
Call Trace:
igrab+0x24/0x100
inotify_show_fdinfo+0x1dc/0x5e0
seq_show+0x397/0x690
Set a DESTROYING flag under conn->lock before starting the walk, and
reject new marks on that connector with -ENOENT. The existing add-mark
error paths undo the temporary group-list entry and the backend's watch
allocation. Do not wait for teardown while holding the group mutex,
which the destroyer needs. Once the old connector is detached, an add
can install a fresh connector as before.
This closes the insertion race for all object types using the common
connector teardown, without changing the mark reference or SRCU lifetime
rules.
Published:
2026-10-28
Score:
n/a
EPSS:
n/a
KEV:
No
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
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 |
|
No data.
No data.
No data available yet.
Remediation
No solution or workaround provided in the CVE record.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
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References
History
Wed, 28 Oct 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: fsnotify: prevent mark additions during connector teardown fsnotify_destroy_marks() keeps a reference to its current mark while it drops conn->lock to destroy the mark. This stabilizes the forward-walk cursor, but does not prevent a new mark from being inserted before it. For example, an inotify watch re-added after IN_IGNORED sorts before the old, detached mark for the same group. The walk can miss the replacement and then detach the entire connector from the object. The replacement is still on its group's marks_list and, for inotify, in the watch IDR. The group mutex no longer protects the connector's object from disappearing. An unprivileged fdinfo read racing the final detach can consequently call igrab(NULL): BUG: KASAN: null-ptr-deref in igrab+0x24/0x100 Write of size 4 at addr 0000000000000148 Call Trace: igrab+0x24/0x100 inotify_show_fdinfo+0x1dc/0x5e0 seq_show+0x397/0x690 Set a DESTROYING flag under conn->lock before starting the walk, and reject new marks on that connector with -ENOENT. The existing add-mark error paths undo the temporary group-list entry and the backend's watch allocation. Do not wait for teardown while holding the group mutex, which the destroyer needs. Once the old connector is detached, an add can install a fresh connector as before. This closes the insertion race for all object types using the common connector teardown, without changing the mark reference or SRCU lifetime rules. | |
| Title | fsnotify: prevent mark additions during connector teardown | |
| 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: 2026-10-28T10:35:29.760Z
Reserved: 2026-09-25T10:25:14.399Z
Link: CVE-2026-99175
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-28T11:17:38.150
Modified: 2026-10-28T11:17:38.150
Link: CVE-2026-99175
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.