In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix circular locking dependency in ocfs2_init_acl()
A lockdep warning indicates a circular locking dependency between
`&oi->ip_xattr_sem` and `&journal->j_trans_barrier`:
WARNING: possible circular locking dependency detected
is trying to acquire lock:
(&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_init_acl+0x2fd/0x7e0
fs/ocfs2/acl.c:367
but task is already holding lock:
(&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3ab/0x700
fs/ocfs2/journal.c:369
The deadlock involves two code paths: Path 1 (setxattr) where
`ocfs2_xattr_set()` acquires `ip_xattr_sem` (write) and then starts a
transaction, which acquires `j_trans_barrier` (read); and Path 2
(mkdir/mknod) where `ocfs2_mknod()` starts a transaction (`j_trans_barrier`
read) and then calls `ocfs2_init_acl()`, which attempts to acquire
`ip_xattr_sem` (read) on the parent directory to retrieve the default ACL.
Because rw_semaphores are subject to writer priority, a pending writer on
`j_trans_barrier` (e.g., the journal commit thread) can cause Path 1 to
block, while Path 2 is blocked waiting for Path 1 to release
`ip_xattr_sem`.
The patch fixes the lock ordering by precomputing the ACL state before
starting the OCFS2 transaction, while preserving POSIX ACL storage
semantics and the existing inode/security initialization order. By reading
the parent directory's default ACL and preparing the new inode's ACLs
outside the transaction, `ip_xattr_sem` is always acquired before
`j_trans_barrier`.
`struct ocfs2_acl_state` encapsulates the prepared ACL state, while
`ocfs2_acl_init_prepare()` and `ocfs2_acl_init_release()` avoid code
duplication between `ocfs2_mknod()` and `ocfs2_init_security_and_acl()`.
`ocfs2_calc_xattr_init()` and `ocfs2_init_acl()` use this precomputed
state, removing internal `ip_xattr_sem` acquisition and redundant disk
reads.
Additionally, remove the `ip_xattr_sem` acquisition from
`ocfs2_xattr_set_handle()`. This function is only used while initializing a
new inode that has not yet been inserted into the inode hash or attached to
a dentry, meaning there is no risk of concurrent access and the lock is
unnecessary.
ocfs2: fix circular locking dependency in ocfs2_init_acl()
A lockdep warning indicates a circular locking dependency between
`&oi->ip_xattr_sem` and `&journal->j_trans_barrier`:
WARNING: possible circular locking dependency detected
is trying to acquire lock:
(&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_init_acl+0x2fd/0x7e0
fs/ocfs2/acl.c:367
but task is already holding lock:
(&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3ab/0x700
fs/ocfs2/journal.c:369
The deadlock involves two code paths: Path 1 (setxattr) where
`ocfs2_xattr_set()` acquires `ip_xattr_sem` (write) and then starts a
transaction, which acquires `j_trans_barrier` (read); and Path 2
(mkdir/mknod) where `ocfs2_mknod()` starts a transaction (`j_trans_barrier`
read) and then calls `ocfs2_init_acl()`, which attempts to acquire
`ip_xattr_sem` (read) on the parent directory to retrieve the default ACL.
Because rw_semaphores are subject to writer priority, a pending writer on
`j_trans_barrier` (e.g., the journal commit thread) can cause Path 1 to
block, while Path 2 is blocked waiting for Path 1 to release
`ip_xattr_sem`.
The patch fixes the lock ordering by precomputing the ACL state before
starting the OCFS2 transaction, while preserving POSIX ACL storage
semantics and the existing inode/security initialization order. By reading
the parent directory's default ACL and preparing the new inode's ACLs
outside the transaction, `ip_xattr_sem` is always acquired before
`j_trans_barrier`.
`struct ocfs2_acl_state` encapsulates the prepared ACL state, while
`ocfs2_acl_init_prepare()` and `ocfs2_acl_init_release()` avoid code
duplication between `ocfs2_mknod()` and `ocfs2_init_security_and_acl()`.
`ocfs2_calc_xattr_init()` and `ocfs2_init_acl()` use this precomputed
state, removing internal `ip_xattr_sem` acquisition and redundant disk
reads.
Additionally, remove the `ip_xattr_sem` acquisition from
`ocfs2_xattr_set_handle()`. This function is only used while initializing a
new inode that has not yet been inserted into the inode hash or attached to
a dentry, meaning there is no risk of concurrent access and the lock is
unnecessary.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
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Advisories
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Fixes
Solution
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Workaround
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References
History
Thu, 24 Sep 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix circular locking dependency in ocfs2_init_acl() A lockdep warning indicates a circular locking dependency between `&oi->ip_xattr_sem` and `&journal->j_trans_barrier`: WARNING: possible circular locking dependency detected is trying to acquire lock: (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_init_acl+0x2fd/0x7e0 fs/ocfs2/acl.c:367 but task is already holding lock: (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3ab/0x700 fs/ocfs2/journal.c:369 The deadlock involves two code paths: Path 1 (setxattr) where `ocfs2_xattr_set()` acquires `ip_xattr_sem` (write) and then starts a transaction, which acquires `j_trans_barrier` (read); and Path 2 (mkdir/mknod) where `ocfs2_mknod()` starts a transaction (`j_trans_barrier` read) and then calls `ocfs2_init_acl()`, which attempts to acquire `ip_xattr_sem` (read) on the parent directory to retrieve the default ACL. Because rw_semaphores are subject to writer priority, a pending writer on `j_trans_barrier` (e.g., the journal commit thread) can cause Path 1 to block, while Path 2 is blocked waiting for Path 1 to release `ip_xattr_sem`. The patch fixes the lock ordering by precomputing the ACL state before starting the OCFS2 transaction, while preserving POSIX ACL storage semantics and the existing inode/security initialization order. By reading the parent directory's default ACL and preparing the new inode's ACLs outside the transaction, `ip_xattr_sem` is always acquired before `j_trans_barrier`. `struct ocfs2_acl_state` encapsulates the prepared ACL state, while `ocfs2_acl_init_prepare()` and `ocfs2_acl_init_release()` avoid code duplication between `ocfs2_mknod()` and `ocfs2_init_security_and_acl()`. `ocfs2_calc_xattr_init()` and `ocfs2_init_acl()` use this precomputed state, removing internal `ip_xattr_sem` acquisition and redundant disk reads. Additionally, remove the `ip_xattr_sem` acquisition from `ocfs2_xattr_set_handle()`. This function is only used while initializing a new inode that has not yet been inserted into the inode hash or attached to a dentry, meaning there is no risk of concurrent access and the lock is unnecessary. | |
| Title | ocfs2: fix circular locking dependency in ocfs2_init_acl() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T15:51:28.355Z
Reserved: 2026-09-17T16:02:15.096Z
Link: CVE-2026-93252
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-24T16:17:21.463
Modified: 2026-09-24T16:17:21.463
Link: CVE-2026-93252
Redhat
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OpenCVE Enrichment
No data.
Weaknesses
No weakness.