In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on ino and xnid
syzbot reported a f2fs bug as below:
INFO: task syz-executor140:5308 blocked for more than 143 seconds.
Not tainted 6.14.0-rc7-syzkaller-00069-g81e4f8d68c66 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor140 state:D stack:24016 pid:5308 tgid:5308 ppid:5306 task_flags:0x400140 flags:0x00000006
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x190e/0x4c90 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6857
io_schedule+0x8d/0x110 kernel/sched/core.c:7690
folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1317
__folio_lock mm/filemap.c:1664 [inline]
folio_lock include/linux/pagemap.h:1163 [inline]
__filemap_get_folio+0x147/0xb40 mm/filemap.c:1917
pagecache_get_page+0x2c/0x130 mm/folio-compat.c:87
find_get_page_flags include/linux/pagemap.h:842 [inline]
f2fs_grab_cache_page+0x2b/0x320 fs/f2fs/f2fs.h:2776
__get_node_page+0x131/0x11b0 fs/f2fs/node.c:1463
read_xattr_block+0xfb/0x190 fs/f2fs/xattr.c:306
lookup_all_xattrs fs/f2fs/xattr.c:355 [inline]
f2fs_getxattr+0x676/0xf70 fs/f2fs/xattr.c:533
__f2fs_get_acl+0x52/0x870 fs/f2fs/acl.c:179
f2fs_acl_create fs/f2fs/acl.c:375 [inline]
f2fs_init_acl+0xd7/0x9b0 fs/f2fs/acl.c:418
f2fs_init_inode_metadata+0xa0f/0x1050 fs/f2fs/dir.c:539
f2fs_add_inline_entry+0x448/0x860 fs/f2fs/inline.c:666
f2fs_add_dentry+0xba/0x1e0 fs/f2fs/dir.c:765
f2fs_do_add_link+0x28c/0x3a0 fs/f2fs/dir.c:808
f2fs_add_link fs/f2fs/f2fs.h:3616 [inline]
f2fs_mknod+0x2e8/0x5b0 fs/f2fs/namei.c:766
vfs_mknod+0x36d/0x3b0 fs/namei.c:4191
unix_bind_bsd net/unix/af_unix.c:1286 [inline]
unix_bind+0x563/0xe30 net/unix/af_unix.c:1379
__sys_bind_socket net/socket.c:1817 [inline]
__sys_bind+0x1e4/0x290 net/socket.c:1848
__do_sys_bind net/socket.c:1853 [inline]
__se_sys_bind net/socket.c:1851 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1851
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Let's dump and check metadata of corrupted inode, it shows its xattr_nid
is the same to its i_ino.
dump.f2fs -i 3 chaseyu.img.raw
i_xattr_nid [0x 3 : 3]
So that, during mknod in the corrupted directory, it tries to get and
lock inode page twice, result in deadlock.
- f2fs_mknod
- f2fs_add_inline_entry
- f2fs_get_inode_page --- lock dir's inode page
- f2fs_init_acl
- f2fs_acl_create(dir,..)
- __f2fs_get_acl
- f2fs_getxattr
- lookup_all_xattrs
- __get_node_page --- try to lock dir's inode page
In order to fix this, let's add sanity check on ino and xnid.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it