Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: nvme-fabrics: use reserved tag for reg read/write command In some scenarios, if too many commands are issued by nvme command in the same time by user tasks, this may exhaust all tags of admin_q. If a reset (nvme reset or IO timeout) occurs before these commands finish, reconnect routine may fail to update nvme regs due to insufficient tags, which will cause kernel hang forever. In order to workaround this issue, maybe we can let reg_read32()/reg_read64()/reg_write32() use reserved tags. This maybe safe for nvmf: 1. For the disable ctrl path, we will not issue connect command 2. For the enable ctrl / fw activate path, since connect and reg_xx() are called serially. So the reserved tags may still be enough while reg_xx() use reserved tags.

Affected versions

Linux: e7832cb48a654cd12b2bc9181b2f0ad49d526ac6 through before cc91c461cf3902993364ea85d8814ba7786c95b1 (git); e7832cb48a654cd12b2bc9181b2f0ad49d526ac6 through before 165da9c67a26f08c9b956c15d701da7690f45bcb (git); e7832cb48a654cd12b2bc9181b2f0ad49d526ac6 through before 7dc3bfcb4c9cc58970fff6aaa48172cb224d85aa (git); 5.4 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.