Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: atm/fore200e: Fix possible data race in fore200e_open() Protect access to fore200e->available_cell_rate with rate_mtx lock in the error handling path of fore200e_open() to prevent a data race. The field fore200e->available_cell_rate is a shared resource used to track available bandwidth. It is concurrently accessed by fore200e_open(), fore200e_close(), and fore200e_change_qos(). In fore200e_open(), the lock rate_mtx is correctly held when subtracting vcc->qos.txtp.max_pcr from available_cell_rate to reserve bandwidth. However, if the subsequent call to fore200e_activate_vcin() fails, the function restores the reserved bandwidth by adding back to available_cell_rate without holding the lock. This introduces a race condition because available_cell_rate is a global device resource shared across all VCCs. If the error path in fore200e_open() executes concurrently with operations like fore200e_close() or fore200e_change_qos() on other VCCs, a read-modify-write race occurs. Specifically, the error path reads the rate without the lock. If another CPU acquires the lock and modifies the rate (e.g., releasing bandwidth in fore200e_close()) between this read and the subsequent write, the error path will overwrite the concurrent update with a stale value. This results in incorrect bandwidth accounting.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 1b60f42a639999c37da7f1fbfa1ad29cf4cbdd2d; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before bd1415efbab507b9b995918105eef953013449dd; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before ed34c70d88e2b8b9bc6c3ede88751186d6c6d5d1; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 9917ba597cf95f307778e495f71ff25a5064d167; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 667ac868823224374f819500adc5baa2889c7bc5; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 6610361458e7eb6502dd3182f586f91fcc218039; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 82fca3d8a4a34667f01ec2351a607135249c9cff |
| Linux / Linux | affected 2.6.12; unaffected 0 before 2.6.12; unaffected 5.10.247 through 5.10.*; unaffected 5.15.197 through 5.15.*; unaffected 6.1.159 through 6.1.*; unaffected 6.6.119 through 6.6.*; unaffected 6.12.61 through 6.12.*; unaffected 6.17.11 through 6.17.*; unaffected 6.18 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/1b60f42a639999c37da7f1fbfa1ad29cf4cbdd2d
- https://git.kernel.org/stable/c/bd1415efbab507b9b995918105eef953013449dd
- https://git.kernel.org/stable/c/ed34c70d88e2b8b9bc6c3ede88751186d6c6d5d1
- https://git.kernel.org/stable/c/9917ba597cf95f307778e495f71ff25a5064d167
- https://git.kernel.org/stable/c/667ac868823224374f819500adc5baa2889c7bc5
- https://git.kernel.org/stable/c/6610361458e7eb6502dd3182f586f91fcc218039
- https://git.kernel.org/stable/c/82fca3d8a4a34667f01ec2351a607135249c9cff