Vulnerability Details CVE-2024-53186
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 5.6%
CVSS Severity
CVSS v3 Score 7.0
Products affected by CVE-2024-53186
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cpe:2.3:o:linux:linux_kernel:6.10.14
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cpe:2.3:o:linux:linux_kernel:6.11.10
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cpe:2.3:o:linux:linux_kernel:6.11.3
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cpe:2.3:o:linux:linux_kernel:6.11.4
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cpe:2.3:o:linux:linux_kernel:6.11.5
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cpe:2.3:o:linux:linux_kernel:6.11.6
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cpe:2.3:o:linux:linux_kernel:6.11.7
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cpe:2.3:o:linux:linux_kernel:6.11.8
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cpe:2.3:o:linux:linux_kernel:6.11.9
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cpe:2.3:o:linux:linux_kernel:6.12
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cpe:2.3:o:linux:linux_kernel:6.12.1
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cpe:2.3:o:linux:linux_kernel:6.6.55
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cpe:2.3:o:linux:linux_kernel:6.6.56
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cpe:2.3:o:linux:linux_kernel:6.6.57
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cpe:2.3:o:linux:linux_kernel:6.6.58
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cpe:2.3:o:linux:linux_kernel:6.6.59
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cpe:2.3:o:linux:linux_kernel:6.6.60
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cpe:2.3:o:linux:linux_kernel:6.6.61
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cpe:2.3:o:linux:linux_kernel:6.6.62
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cpe:2.3:o:linux:linux_kernel:6.6.63