// For flags

CVE-2025-38347

f2fs: fix to do sanity check on ino and xnid

Severity Score

6.6
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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: <TASK> 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.

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: <TASK> 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.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
Complete
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2025-04-16 CVE Reserved
  • 2025-07-10 CVE Published
  • 2025-07-11 CVE Updated
  • 2025-07-16 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.8 < 6.6.95
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.8 < 6.6.95"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.8 < 6.12.35
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.8 < 6.12.35"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.8 < 6.15.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.8 < 6.15.4"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.8 < 6.16-rc1
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.8 < 6.16-rc1"
en
Affected