Описание
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 forconn->r_countto reach zero:wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);- Meanwhile, 
handle_ksmbd_work()decrementsconn->r_countusingatomic_dec_return(&conn->r_count), and if it reaches zero, callsksmbd_conn_free(), which freesconn. - However, after 
handle_ksmbd_work()decrementsconn->r_count, it may still accessconn->r_count_qin the following line:waitqueue_active(&conn->r_count_q)orwake_up(&conn->r_count_q)This results in a UAF,... 
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 forconn->r_countto reach zero:wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);- Meanwhile, 
handle_ksmbd_work()decrementsconn->r_countusingatomic_dec_return(&conn->r_count), and if it reaches zero, callsksmbd_conn_free(), which freesconn. - However, after 
handle_ksmbd_work()decrementsconn->r_count, it may still accessconn->r_count_qin the following line:waitqueue_active(&conn->r_count_q)orwake_up(&conn->r_count_q)This results in a UAF, asconnhas already been freed. 
The discovery of this UAF can be referenced in the following PR for syzkaller's support for SMB requests.
Ссылки
- https://nvd.nist.gov/vuln/detail/CVE-2024-53186
 - https://git.kernel.org/stable/c/96261adb998a3b513468b6ce17dbec76be5507d4
 - https://git.kernel.org/stable/c/9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e
 - https://git.kernel.org/stable/c/a96f9eb7add30ba0fafcfe7b7aca090978196800
 - https://git.kernel.org/stable/c/f20b77f7897e6aab9ce5527e6016ad2be5d70a33
 
Связанные уязвимости
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 ...
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 ...
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
In the Linux kernel, the following vulnerability has been resolved: k ...