CVE-2022-49274

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

ocfs2: fix crash when mount with quota enabled

There is a reported crash when mounting ocfs2 with quota enabled.

RIP: 0010:ocfs2_qinfo_lock_res_init+0x44/0x50 [ocfs2] Call Trace: ocfs2_local_read_info+0xb9/0x6f0 [ocfs2] dquot_load_quota_sb+0x216/0x470 dquot_load_quota_inode+0x85/0x100 ocfs2_enable_quotas+0xa0/0x1c0 [ocfs2] ocfs2_fill_super.cold+0xc8/0x1bf [ocfs2] mount_bdev+0x185/0x1b0 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x465/0xac0 __x64_sys_mount+0x103/0x140

It is caused by when initializing dqi_gqlock, the corresponding dqi_type and dqi_sb are not properly initialized.

This issue is introduced by commit 6c85c2c72819, which wants to avoid accessing uninitialized variables in error cases. So make global quota info properly initialized.

Red Hat Enterprise Linux is not vulnerable to this flaw as the problematic upstream commit was never incorporated into Red Hat enterprise kernels. Additionally, the Oracle Cluster File System version 2 (OCFS2) is not supported or enabled in standard enterprise distributions. Exploitation would require mounting a filesystem with quota options, an operation restricted to privileged users. As a result, standard deployments face no operational impact or denial-of-service risk from this issue.