CVE-2022-48745

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: Use del_timer_sync in fw reset flow of halting poll

Substitute del_timer() with del_timer_sync() in fw reset polling deactivation flow, in order to prevent a race condition which occurs when del_timer() is called and timer is deactivated while another process is handling the timer interrupt. A situation that led to the following call trace: RIP: 0010:run_timer_softirq+0x137/0x420 recalibrate_cpu_khz+0x10/0x10 ktime_get+0x3e/0xa0 ? sched_clock_cpu+0xb/0xc0 __do_softirq+0xf5/0x2ea irq_exit_rcu+0xc1/0xf0 sysvec_apic_timer_interrupt+0x9e/0xc0 asm_sysvec_apic_timer_interrupt+0x12/0x20

Weakness

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Software

Extended Description

A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Potential Mitigations

• Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
• Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://git.kernel.org/stable/c/2a038dd1d942f8fbc495c58fa592ff24af05f1c2
• https://git.kernel.org/stable/c/3c5193a87b0fea090aa3f769d020337662d87b5e
• https://git.kernel.org/stable/c/502c37b033fab7cde3e95a570af4f073306be45e
• https://git.kernel.org/stable/c/f895ebeb44d09d02674cfdd0cfc2bf687603918c
• https://git.kernel.org/stable/c/2a038dd1d942f8fbc495c58fa592ff24af05f1c2
• https://git.kernel.org/stable/c/3c5193a87b0fea090aa3f769d020337662d87b5e
• https://git.kernel.org/stable/c/502c37b033fab7cde3e95a570af4f073306be45e
• https://git.kernel.org/stable/c/f895ebeb44d09d02674cfdd0cfc2bf687603918c