CVE-2024-47694

/// Technical description

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

IB/mlx5: Fix UMR pd cleanup on error flow of driver init

The cited commit moves the pd allocation from function

mlx5r_umr_resource_cleanup() to a new function mlx5r_umr_cleanup().

So the fix in commit [1] is broken. In error flow, will hit panic [2].

Fix it by checking pd pointer to avoid panic if it is NULL;

[1] RDMA/mlx5: Fix UMR cleanup on error flow of driver init

[2]

[ 347.567063] infiniband mlx5_0: Couldn't register device with driver model

[ 347.591382] BUG: kernel NULL pointer dereference, address: 0000000000000020

[ 347.593438] #PF: supervisor read access in kernel mode

[ 347.595176] #PF: error_code(0x0000) - not-present page

[ 347.596962] PGD 0 P4D 0

[ 347.601361] RIP: 0010:ib_dealloc_pd_user+0x12/0xc0 [ib_core]

[ 347.604171] RSP: 0018:ffff888106293b10 EFLAGS: 00010282

[ 347.604834] RAX: 0000000000000000 RBX: 000000000000000e RCX: 0000000000000000

[ 347.605672] RDX: ffff888106293ad0 RSI:

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References