CVE-2024-49875

/// Technical description

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

nfsd: map the EBADMSG to nfserr_io to avoid warning

Ext4 will throw -EBADMSG through ext4_readdir when a checksum error

occurs, resulting in the following WARNING.

Fix it by mapping EBADMSG to nfserr_io.

nfsd_buffered_readdir

iterate_dir // -EBADMSG -74

ext4_readdir // .iterate_shared

ext4_dx_readdir

ext4_htree_fill_tree

htree_dirblock_to_tree

ext4_read_dirblock

__ext4_read_dirblock

ext4_dirblock_csum_verify

warn_no_space_for_csum

__warn_no_space_for_csum

return ERR_PTR(-EFSBADCRC) // -EBADMSG -74

nfserrno // WARNING

[ 161.115610] ------------[ cut here ]------------

[ 161.116465] nfsd: non-standard errno: -74

[ 161.117315] WARNING: CPU: 1 PID: 780 at fs/nfsd/nfsproc.c:878 nfserrno+0x9d/0xd0

[ 161.118596] Modules linked in:

[ 161.119243] CPU: 1 PID: 780 Comm: nfsd Not tainted 5.10.0-00014-g79679361fd5d #138

[ 161.120684] Hardware name: QEMU Stan

/// 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