Description
In the Linux kernel, the following vulnerability has been resolved: ceph: fix multifs mds auth caps issue The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph cluster. The bug causes multiple issues w.r.t user authentication, following is one such example. Steps to Reproduce (on vstart cluster): 1. Create two file systems in a cluster, say 'fsname1' and 'fsname2' 2. Authorize read only permission to the user 'client.usr' on fs 'fsname1' $ceph fs authorize fsname1 client.usr / r 3. Authorize read and write permission to the same user 'client.usr' on fs 'fsname2' $ceph fs authorize fsname2 client.usr / rw 4. Update the keyring $ceph auth get client.usr >> ./keyring With above permssions for the user 'client.usr', following is the expectation. a. The 'client.usr' should be able to only read the contents and not allowed to create or delete files on file system 'fsname1'. b. The 'client.usr' should be able to read/write on file system 'fsname2'. But, with this bug, the 'client.usr' is allowed to read/write on file system 'fsname1'. See below. 5. Mount the file system 'fsname1' with the user 'client.usr' $sudo bin/mount.ceph usr@.fsname1=/ /kmnt_fsname1_usr/ 6. Try creating a file on file system 'fsname1' with user 'client.usr'. This should fail but passes with this bug. $touch /kmnt_fsname1_usr/file1 7. Mount the file system 'fsname1' with the user 'client.admin' and create a file. $sudo bin/mount.ceph admin@.fsname1=/ /kmnt_fsname1_admin $echo "data" > /kmnt_fsname1_admin/admin_file1 8. Try removing an existing file on file system 'fsname1' with the user 'client.usr'. This shoudn't succeed but succeeds with the bug. $rm -f /kmnt_fsname1_usr/admin_file1 For more information, please take a look at the corresponding mds/fuse patch and tests added by looking into the tracker mentioned below. v2: Fix a possible null dereference in doutc v3: Don't store fsname from mdsmap, validate against ceph_mount_options's fsname and use it v4: Code refactor, better warning message and fix possible compiler warning [ Slava.Dubeyko: "fsname check failed" -> "fsname mismatch" ]
Product status
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 07640d34a781bb2e39020a39137073c03c4aa932
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 22c73d52a6d05c5a2053385c0d6cd9984732799d
6.12.58 (semver)
6.17.8 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/07640d34a781bb2e39020a39137073c03c4aa932
git.kernel.org/...c/ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523
git.kernel.org/...c/22c73d52a6d05c5a2053385c0d6cd9984732799d
Data based on CVE®. Copyright © 1999-2025, The MITRE Corporation. All rights reserved.
