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scsi: core: Fix unremoved procfs host directory regression (Linux Linux)

CVE-2024-26935
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.24 % · centile 15 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Modified

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Description

In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix unremoved procfs host directory regression Commit fc663711b944 ("scsi: core: Remove the /proc/scsi/${proc_name} directory earlier") fixed a bug related to modules loading/unloading, by adding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led to a potential duplicate call to the hostdir_rm() routine, since it's also called from scsi_host_dev_release(). That triggered a regression report, which was then fixed by commit be03df3d4bfe ("scsi: core: Fix a procfs host directory removal regression"). The fix just dropped the hostdir_rm() call from dev_release(). But it happens that this proc directory is created on scsi_host_alloc(), and that function "pairs" with scsi_host_dev_release(), while scsi_remove_host() pairs with scsi_add_host(). In other words, it seems the reason for removing the proc directory on dev_release() was meant to cover cases in which a SCSI host structure was allocated, but the call to scsi_add_host() didn't happen. And that pattern happens to exist in some error paths, for example. Syzkaller causes that by using USB raw gadget device, error'ing on usb-storage driver, at usb_stor_probe2(). By checking that path, we can see that the BadDevice label leads to a scsi_host_put() after a SCSI host allocation, but there's no call to scsi_add_host() in such path. That leads to messages like this in dmesg (and a leak of the SCSI host proc structure): usb-storage 4-1:87.51: USB Mass Storage device detected proc_dir_entry 'scsi/usb-storage' already registered WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376 The proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(), but guard that with the state check for SHOST_CREATED; there is even a comment in scsi_host_dev_release() detailing that: such conditional is meant for cases where the SCSI host was allocated but there was no calls to {add,remove}_host(), like the usb-storage case. This is what we propose here and with that, the error path of usb-storage does not trigger the warning anymore.

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 88c3d3bb6469cea929ac68fd326bdcbefcdfdd83 < 0053f15d50d50c9312d8ab9c11e2e405812dfcac ; affected 68c665bb185037e7eb66fb792c61da9d7151e99c < 5c2386ba80e779a92ec3bb64ccadbedd88f779b1 ; affected 2a764d55e938743efa7c2cba7305633bcf227f09 < cea234bb214b17d004dfdccce4491e6ff57c96ee ; affected 7e0ae8667fcdd99d1756922e1140cac75f5fa279 < 3678cf67ff7136db1dd3bf63c361650db5d92889 ; affected be03df3d4bfe7e8866d4aa43d62e648ffe884f5f < d4c34782b6d7b1e68d18d9549451b19433bd4c6c ; affected be03df3d4bfe7e8866d4aa43d62e648ffe884f5f < e293c773c13b830cdc251f155df2254981abc320
Linux · Linuxaffected 6.3 ; unaffected 0 < 6.3 ; unaffected 5.4.274 ≤ 5.4.* ; unaffected 5.10.215 ≤ 5.10.* ; unaffected 5.15.154 ≤ 5.15.* ; unaffected 6.1.84 ≤ 6.1.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD