CVE-2024-46682

/// Technical description

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

nfsd: prevent panic for nfsv4.0 closed files in nfs4_show_open

Prior to commit 3f29cc82a84c ("nfsd: split sc_status out of

sc_type") states_show() relied on sc_type field to be of valid

type before calling into a subfunction to show content of a

particular stateid. From that commit, we split the validity of

the stateid into sc_status and no longer changed sc_type to 0

while unhashing the stateid. This resulted in kernel oopsing

for nfsv4.0 opens that stay around and in nfs4_show_open()

would derefence sc_file which was NULL.

Instead, for closed open stateids forgo displaying information

that relies of having a valid sc_file.

To reproduce: mount the server with 4.0, read and close

a file and then on the server cat /proc/fs/nfsd/clients/2/states

[ 513.590804] Call trace:

[ 513.590925] _raw_spin_lock+0xcc/0x160

[ 513.591119] nfs4_show_open+0x78/0x2c0 [nfsd]

[ 513.591412] states_show+0x44c/0x488 [nfsd]

[ 513.5

/// 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