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.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-6999-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6999-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7004-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7008-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7029-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7166-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7166-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7166-3 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7166-4 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7186-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-7186-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7194-1 | Linux kernel (Azure) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Thu, 17 Oct 2024 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:o:linux:linux_kernel:5.11:*:*:*:*:*:*:* | |
| Metrics |
ssvc
|
Thu, 17 Oct 2024 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Tue, 10 Sep 2024 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Thu, 29 Aug 2024 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
threat_severity
|
threat_severity
|
Mon, 19 Aug 2024 21:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T09:16:20.926Z
Reserved: 2024-06-25T14:23:23.744Z
Link: CVE-2024-39463
Updated: 2024-08-02T04:26:15.245Z
Status : Modified
Published: 2024-06-25T15:15:14.760
Modified: 2024-11-21T09:27:43.050
Link: CVE-2024-39463
OpenCVE Enrichment
No data.
Ubuntu USN