In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in SMB request handling
A race condition exists between SMB request handling in
`ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the
workqueue handler `handle_ksmbd_work()`. This leads to a UAF.
- KASAN: slab-use-after-free Read in handle_ksmbd_work
- KASAN: slab-use-after-free in rtlock_slowlock_locked
This race condition arises as follows:
- `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero:
`wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);`
- Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using
`atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls
`ksmbd_conn_free()`, which frees `conn`.
- However, after `handle_ksmbd_work()` decrements `conn->r_count`,
it may still access `conn->r_count_q` in the following line:
`waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)`
This results in a UAF, as `conn` has already been freed.
The discovery of this UAF can be referenced in the following PR for
syzkaller's support for SMB requests.
Metrics
Affected Vendors & Products
References
History
Tue, 14 Jan 2025 17:45:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | CWE-362 CWE-416 |
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CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
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Metrics |
cvssV3_1
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cvssV3_1
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Mon, 30 Dec 2024 01:30:00 +0000
Type | Values Removed | Values Added |
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References |
| |
Metrics |
threat_severity
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cvssV3_1
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Fri, 27 Dec 2024 14:00:00 +0000
Type | Values Removed | Values Added |
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Description | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in SMB request handling A race condition exists between SMB request handling in `ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the workqueue handler `handle_ksmbd_work()`. This leads to a UAF. - KASAN: slab-use-after-free Read in handle_ksmbd_work - KASAN: slab-use-after-free in rtlock_slowlock_locked This race condition arises as follows: - `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero: `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);` - Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls `ksmbd_conn_free()`, which frees `conn`. - However, after `handle_ksmbd_work()` decrements `conn->r_count`, it may still access `conn->r_count_q` in the following line: `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)` This results in a UAF, as `conn` has already been freed. The discovery of this UAF can be referenced in the following PR for syzkaller's support for SMB requests. | |
Title | ksmbd: fix use-after-free in SMB request handling | |
References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-12-27T13:49:29.215Z
Updated: 2024-12-27T13:49:29.215Z
Reserved: 2024-11-19T17:17:25.012Z
Link: CVE-2024-53186
Vulnrichment
No data.
NVD
Status : Analyzed
Published: 2024-12-27T14:15:26.083
Modified: 2025-01-14T17:20:36.107
Link: CVE-2024-53186
Redhat