RDMA/irdma: Prevent user-triggered null deref on QP create

Overview

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

RDMA/irdma: Prevent user-triggered null deref on QP create

Previously, the user QP creation path would only attempt to populate iwqp->iwpbl if the user-provided req.user_wqe_bufs field was non-zero. The problem is that iwqp->iwpbl is unconditionally dereferenced later on in irdma_setup_virt_qp.

While there was a check for iwqp->iwpbl != NULL, this check would only occur if req.user_wqe_bufs was non-zero. The end result is that a user could send a zero user_wqe_bufs value and trigger a null ptr deref.

Fix this by unconditionally calling irdma_get_pbl and bailing if it fails, similar to the CQ and SRQ paths.

Affected

• Linux >= b48c24c2d710cf34810c555dcef883a3d35a9c08 < d52ff592abfcd56234f266aa245c489f70b1c554
• Linux >= b48c24c2d710cf34810c555dcef883a3d35a9c08 < ad68e0b759f9569f0dfea84f035c91eadb979802
• Linux >= b48c24c2d710cf34810c555dcef883a3d35a9c08 < ec675b4cdfd378d8c9dd8c93126c024f2469bd79
• Linux >= b48c24c2d710cf34810c555dcef883a3d35a9c08 < 728211c815f6eef28dd3df2a5b6297483185aa20
• Linux >= b48c24c2d710cf34810c555dcef883a3d35a9c08 < b9b0889071569d43623c260074e159cd8f26adb1
• Linux 5.14

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.