CVE-2026-99175
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
28/10/2026
Última modificación:
28/10/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
fsnotify: prevent mark additions during connector teardown<br />
<br />
fsnotify_destroy_marks() keeps a reference to its current mark while it<br />
drops conn->lock to destroy the mark. This stabilizes the forward-walk<br />
cursor, but does not prevent a new mark from being inserted before it.<br />
For example, an inotify watch re-added after IN_IGNORED sorts before the<br />
old, detached mark for the same group. The walk can miss the replacement<br />
and then detach the entire connector from the object.<br />
<br />
The replacement is still on its group&#39;s marks_list and, for inotify, in<br />
the watch IDR. The group mutex no longer protects the connector&#39;s object<br />
from disappearing. An unprivileged fdinfo read racing the final detach<br />
can consequently call igrab(NULL):<br />
<br />
BUG: KASAN: null-ptr-deref in igrab+0x24/0x100<br />
Write of size 4 at addr 0000000000000148<br />
Call Trace:<br />
igrab+0x24/0x100<br />
inotify_show_fdinfo+0x1dc/0x5e0<br />
seq_show+0x397/0x690<br />
<br />
Set a DESTROYING flag under conn->lock before starting the walk, and<br />
reject new marks on that connector with -ENOENT. The existing add-mark<br />
error paths undo the temporary group-list entry and the backend&#39;s watch<br />
allocation. Do not wait for teardown while holding the group mutex,<br />
which the destroyer needs. Once the old connector is detached, an add<br />
can install a fresh connector as before.<br />
<br />
This closes the insertion race for all object types using the common<br />
connector teardown, without changing the mark reference or SRCU lifetime<br />
rules.


