Description

In the Linux kernel, the following vulnerability has been resolved:

vhost-scsi: Fix handling of multiple calls to vhost_scsi_set_endpoint

If vhost_scsi_set_endpoint is called multiple times without a
vhost_scsi_clear_endpoint between them, we can hit multiple bugs
found by Haoran Zhang:

1. Use-after-free when no tpgs are found:

This fixes a use after free that occurs when vhost_scsi_set_endpoint is
called more than once and calls after the first call do not find any
tpgs to add to the vs_tpg. When vhost_scsi_set_endpoint first finds
tpgs to add to the vs_tpg array match=true, so we will do:

vhost_vq_set_backend(vq, vs_tpg);
...

kfree(vs->vs_tpg);
vs->vs_tpg = vs_tpg;

If vhost_scsi_set_endpoint is called again and no tpgs are found
match=false so we skip the vhost_vq_set_backend call leaving the
pointer to the vs_tpg we then free via:

kfree(vs->vs_tpg);
vs->vs_tpg = vs_tpg;

If a scsi request is then sent we do:

vhost_scsi_handle_vq -> vhost_scsi_get_req -> vhost_vq_get_backend

which sees the vs_tpg we just did a kfree on.

2. Tpg dir removal hang:

This patch fixes an issue where we cannot remove a LIO/target layer
tpg (and structs above it like the target) dir due to the refcount
dropping to -1.

The problem is that if vhost_scsi_set_endpoint detects a tpg is already
in the vs->vs_tpg array or if the tpg has been removed so
target_depend_item fails, the undepend goto handler will do
target_undepend_item on all tpgs in the vs_tpg array dropping their
refcount to ...

Classification

CVE ID: CVE-2025-22083

Affected Products

Vendor: Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 3.07% (scored less or equal to compared to others)

EPSS Date: 2025-04-20 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-22083
https://git.kernel.org/stable/c/2b34bdc42df047794542f3e220fe989124e4499a
https://git.kernel.org/stable/c/3a19eb3d9818e28f14c818a18dc913344a52ca92
https://git.kernel.org/stable/c/3fd054baf382a426bbf5135ede0fc5673db74d3e
https://git.kernel.org/stable/c/63b449f73ab0dcc0ba11ceaa4c5c70bc86ccf03c
https://git.kernel.org/stable/c/5dd639a1646ef5fe8f4bf270fad47c5c3755b9b6

Timeline