Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Add recursion protection in kernel stack trace recording A bug was reported about an infinite recursion caused by tracing the rcu events with the kernel stack trace trigger enabled. The stack trace code called back into RCU which then called the stack trace again. Expand the ftrace recursion protection to add a set of bits to protect events from recursion. Each bit represents the context that the event is in (normal, softirq, interrupt and NMI). Have the stack trace code use the interrupt context to protect against recursion. Note, the bug showed an issue in both the RCU code as well as the tracing stacktrace code. This only handles the tracing stack trace side of the bug. The RCU fix will be handled separately.

Affected Products 5

References 4

• git.kernel.org https://git.kernel.org/stable/c/19e18e6dabb1bbba76d2809ca7d8ae9e1f5975fe
• git.kernel.org https://git.kernel.org/stable/c/5b7f91acffd2c4c000971553d22efa1e1bb4feae
  Patch
• git.kernel.org https://git.kernel.org/stable/c/5f1ef0dfcb5b7f4a91a9b0e0ba533efd9f7e2cdb
  Patch
• git.kernel.org https://git.kernel.org/stable/c/9b03768037d91ce727effb1c5d92d2c7781bf692

Remediation

• git.kernel.org https://git.kernel.org/stable/c/5b7f91acffd2c4c000971553d22efa1e1bb4feae
  Patch
• git.kernel.org https://git.kernel.org/stable/c/5f1ef0dfcb5b7f4a91a9b0e0ba533efd9f7e2cdb
  Patch