Description
In the Linux kernel, the following vulnerability has been resolved: ceph: fix num_ops off-by-one when crypto allocation fails move_dirty_folio_in_page_array() may fail if the file is encrypted, the dirty folio is not the first in the batch, and it fails to allocate a bounce buffer to hold the ciphertext. When that happens, ceph_process_folio_batch() simply redirties the folio and flushes the current batch -- it can retry that folio in a future batch. However, if this failed folio is not contiguous with the last folio that did make it into the batch, then ceph_process_folio_batch() has already incremented `ceph_wbc->num_ops`; because it doesn-t follow through and add the discontiguous folio to the array, ceph_submit_write() -- which expects that `ceph_wbc->num_ops` accurately reflects the number of contiguous ranges (and therefore the required number of -write extent- ops) in the writeback -- will panic the kernel: BUG_ON(ceph_wbc->op_idx + 1 != req->r_num_ops); This issue can be reprod...
- Published
- 2026-05-27 14:17:27
- Affected versions
- unknown
- Type
- Core software
- Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Operating systems
- Linux