net: cadence: macb: Fix a possible deadlock in macb_halt_tx.

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net: cadence: macb: Fix a possible deadlock in macb_halt_tx. There is a situation where after THALT is set high, TGO stays high as well. Because jiffies are never updated, as we are in a context with interrupts disabled, we never exit that loop and have a deadlock. That deadlock was noticed on a sama5d4 device that stayed locked for days. Use retries instead of jiffies so that the timeout really works and we do not have a deadlock anymore.

References

• https://git.kernel.org/stable/c/0772a608d799ac0d127c0a36047a2725777aba9d
• https://git.kernel.org/stable/c/64675a9c00443b2e8af42af08c38fc1b78b68ba2
• https://git.kernel.org/stable/c/aace6b63892ce8307e502a60fe2f5a4bc6e1cfe7
• https://git.kernel.org/stable/c/1d60c0781c1bbeaa1196b0d8aad5c435f06cb7c4
• https://git.kernel.org/stable/c/3e64d35475aa21d13dab71da51de51923c1a3a48
• https://git.kernel.org/stable/c/84f98955a9de0e0f591df85aa1a44f3ebcf1cb37
• https://git.kernel.org/stable/c/c92d6089d8ad7d4d815ebcedee3f3907b539ff1f