CVE-2026-90140

CVE CVE-2026-90140EUVD EUVD-2026-81733Published 2026-09-17T16:06:37.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: cuse: wait for pending RCU callbacks on module exit Since commit 053fc4f755ad ("fuse: fix UAF in rcu pathwalks"), fuse_conn_put() frees the fuse_conn through call_rcu() rather than synchronously. For cuse, fc->release is cuse_fc_release(), which lives in the cuse module. If the module is removed before the RCU grace period ends, the callback jumps into freed module memory: userspace / module unload | RCU softirq ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ close(/dev/cuse) | cuse_channel_release() | fuse_dev_release() | fuse_conn_put(fch->conn) | call_rcu(delayed_release) ------+---> callback queued | rmmod cuse | cuse_exit() | cuse_channel_destroy() | ... | return | | <module text freed> | | rcu_do_batch() | delayed_release() | fc->release() | -> cuse_fc_release() | ^^^ freed text! The freed module text is unmapped by vfree(), so the jump into the stale callback triggers a page-fault Oops. If the virtual address is subsequently reused, the callback could execute unrelated code (undefined behaviour). Fix this by calling rcu_barrier() in cuse_exit() so that any pending fuse_conn release callback completes before the module is removed.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 6.12.110; 6.6.48 <6.6.157; 5.15.166 <5.15.221; 053fc4f755ad43cf35210677bcba798ccdc48d0c <c40f3f24839f8404325a2099e26c2a04786ae309; patch: 6.1.188; patch: 7.2.6; 053fc4f755ad43cf35210677bcba798ccdc48d0c <a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9; patch: 6.18.52; 535e9bd0e8f8d8cfdc29de7cdb902b5041427fe6 <ac5c499413385cea3e0220d6050408d50842891d; patch: 7.3-rc1; a8f650b93e55764ca9ff8e1ddebc151f57024086 <45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e; 6.1.107 <6.1.188; patch: 6.6.157; 053fc4f755ad43cf35210677bcba798ccdc48d0c <4deb3edead0c0e172cc7349e8855d741d3c5e162; 6.8; 053fc4f755ad43cf35210677bcba798ccdc48d0c <389bd349ddbcf90dbd8a4f2a4ab6e552d53df134; patch: 5.15.221; patch: 0; bfbab62ca69f72bcd14ea30de1fb98f6080ad464 <7fe415e1cd8fa875be263670c0ab47109818abb6

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.