nilfs2: fix potential deadlock with newly created symlinks (Linux Linux)

CVE-2024-50229
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.21 % · centile 11 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential deadlock with newly created symlinks Syzbot reported that page_symlink(), called by nilfs_symlink(), triggers memory reclamation involving the filesystem layer, which can result in circular lock dependencies among the reader/writer semaphore nilfs->ns_segctor_sem, s_writers percpu_rwsem (intwrite) and the fs_reclaim pseudo lock. This is because after commit 21fc61c73c39 ("don't put symlink bodies in pagecache into highmem"), the gfp flags of the page cache for symbolic links are overwritten to GFP_KERNEL via inode_nohighmem(). This is not a problem for symlinks read from the backing device, because the __GFP_FS flag is dropped after inode_nohighmem() is called. However, when a new symlink is created with nilfs_symlink(), the gfp flags remain overwritten to GFP_KERNEL. Then, memory allocation called from page_symlink() etc. triggers memory reclamation including the FS layer, which may call nilfs_evict_inode() or nilfs_dirty_inode(). And these can cause a deadlock if they are called while nilfs->ns_segctor_sem is held: Fix this issue by dropping the __GFP_FS flag from the page cache GFP flags of newly created symlinks in the same way that nilfs_new_inode() and __nilfs_read_inode() do, as a workaround until we adopt nofs allocation scope consistently or improve the locking constraints.

Faiblesses (CWE)

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:HCISA-ADP
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)
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 21fc61c73c3903c4c312d0802da01ec2b323d174 < cc38c596e648575ce58bfc31623a6506eda4b94a ; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 < a1686db1e59f8fc016c4c9361e2119dd206f479a ; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 < c72e0df0b56c1166736dc8eb62070ebb12591447 ; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 < 69548bb663fcb63f9ee0301be808a36b9d78dac3 ; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 < 58c7f44c7b9e5ac7e3b1e5da2572ed7767a12f38 ; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 < 1246d86e7bbde265761932c6e2dce28c69cdcb91
Linux · Linuxaffected 4.5 ; unaffected 0 < 4.5 ; unaffected 4.19.323 ≤ 4.19.* ; unaffected 5.4.285 ≤ 5.4.* ; unaffected 5.10.229 ≤ 5.10.* ; unaffected 5.15.171 ≤ 5.15.*

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