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.
Metrics
Affected Vendors & Products
References
History
Tue, 10 Sep 2024 07:30:00 +0000
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References |
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Thu, 29 Aug 2024 14:45:00 +0000
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threat_severity
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threat_severity
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Mon, 19 Aug 2024 21:30:00 +0000
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First Time appeared |
Linux
Linux linux Kernel |
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CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:* |
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Vendors & Products |
Linux
Linux linux Kernel |
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Metrics |
cvssV3_1
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cvssV3_1
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-06-25T14:25:02.887Z
Updated: 2024-09-10T15:36:18.860Z
Reserved: 2024-06-25T14:23:23.744Z
Link: CVE-2024-39463
Vulnrichment
Updated: 2024-08-02T04:26:15.245Z
NVD
Status : Modified
Published: 2024-06-25T15:15:14.760
Modified: 2024-09-10T16:35:04.250
Link: CVE-2024-39463
Redhat