{"id":"DEBIAN-CVE-2024-39463","details":"In the Linux kernel, the following vulnerability has been resolved:  9p: add missing locking around taking dentry fid list  Fix a use-after-free on dentry's d_fsdata fid list when a thread looks up a fid through dentry while another thread unlinks it:  UAF thread: refcount_t: addition on 0; use-after-free.  p9_fid_get linux/./include/net/9p/client.h:262  v9fs_fid_find+0x236/0x280 linux/fs/9p/fid.c:129  v9fs_fid_lookup_with_uid linux/fs/9p/fid.c:181  v9fs_fid_lookup+0xbf/0xc20 linux/fs/9p/fid.c:314  v9fs_vfs_getattr_dotl+0xf9/0x360 linux/fs/9p/vfs_inode_dotl.c:400  vfs_statx+0xdd/0x4d0 linux/fs/stat.c:248  Freed by:  p9_fid_destroy (inlined)  p9_client_clunk+0xb0/0xe0 linux/net/9p/client.c:1456  p9_fid_put linux/./include/net/9p/client.h:278  v9fs_dentry_release+0xb5/0x140 linux/fs/9p/vfs_dentry.c:55  v9fs_remove+0x38f/0x620 linux/fs/9p/vfs_inode.c:518  vfs_unlink+0x29a/0x810 linux/fs/namei.c:4335  The problem is that d_fsdata was not accessed under d_lock, because d_release() normally is only called once the dentry is otherwise no longer accessible but since we also call it explicitly in v9fs_remove that lock is required: move the hlist out of the dentry under lock then unref its fids once they are no longer accessible.","modified":"2026-09-15T09:03:09.311330159Z","published":"2024-06-25T15:15:14.760Z","upstream":["CVE-2024-39463"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2024-39463"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.94-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-39463.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.9.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-39463.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.9.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-39463.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}