CVE-2026-80528

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ceph: avoid fs reclaim while using current-&gt;journal_info<br /> <br /> handle_reply() stores a `ceph_mds_request` pointer in<br /> `current-&gt;journal_info` while filling the inode and dentry cache from<br /> an MDS reply.<br /> <br /> An allocation in this section can enter direct reclaim and prune<br /> dentries from another filesystem. If this dirties an ext4 inode, ext4<br /> starts a JBD2 transaction. JBD2 interprets the Ceph request in<br /> `current-&gt;journal_info` as a journal handle and dereferences the<br /> request&amp;#39;s `r_tid` as `h_transaction`, causing a kernel crash, e.g.:<br /> <br /> Unable to handle kernel paging request at virtual address 00000000077b4818<br /> [...]<br /> Internal error: Oops: 0000000096000004 [#1] SMP<br /> Modules linked in:<br /> CPU: 6 UID: 0 PID: 2699135 Comm: kworker/6:3 Tainted: G W 6.18.38-i3 #1113 NONE<br /> [...]<br /> Workqueue: ceph-msgr ceph_con_workfn<br /> pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> pc : jbd2__journal_start+0x2c/0x208<br /> lr : __ext4_journal_start_sb+0x100/0x178<br /> [...]<br /> Call trace:<br /> jbd2__journal_start+0x2c/0x208 (P)<br /> __ext4_journal_start_sb+0x100/0x178<br /> ext4_dirty_inode+0x3c/0x90<br /> __mark_inode_dirty+0x58/0x400<br /> iput.part.0+0x2b0/0x370<br /> iput+0x18/0x30<br /> dentry_unlink_inode+0xc0/0x158<br /> __dentry_kill+0x80/0x250<br /> shrink_dentry_list+0x90/0x130<br /> prune_dcache_sb+0x60/0x98<br /> super_cache_scan+0xe8/0x190<br /> do_shrink_slab+0x174/0x388<br /> shrink_slab+0xd8/0x4c0<br /> shrink_node+0x31c/0x908<br /> do_try_to_free_pages+0xd0/0x508<br /> try_to_free_pages+0x11c/0x238<br /> __alloc_frozen_pages_noprof+0x4d0/0xdd0<br /> __folio_alloc_noprof+0x18/0x70<br /> __filemap_get_folio+0x248/0x440<br /> ceph_readdir_prepopulate+0x570/0x9e8<br /> mds_dispatch+0x1424/0x1ba0<br /> ceph_con_process_message+0x74/0xa0<br /> ceph_con_v1_try_read+0x3a0/0x1510<br /> ceph_con_workfn+0x260/0x460<br /> <br /> Enter a scoped NOFS allocation context and leave it after clearing<br /> `journal_info`. This prevents filesystem reclaim from recursing into<br /> another filesystem while the field contains Ceph-private data.