IMA measurement of a configfs file causes process_measurement() to hold iint->mutex while performing a kernel_read() to hash it, which re-enters configfs's own file locking (buffer->mutex, frag_sem).
Separately, opening any file with O_TRUNC now causes ima_file_truncate() to take iint->mutex to reset the cached action flags, while sb_writers is already held for that mount. When a configfs-backed nvmet namespace is involved, these two independent lock chains combine into a cycle: iint->mutex -> configfs locks -> subsys->lock -> sb_writers -> iint->mutex Add configfs to the builtin don't measure/appraise rules, similarly to other pseudo file systems, so IMA never takes iint->mutex for configfs file in the first place. Link: https://lore.kernel.org/all/[email protected]/#t Signed-off-by: Frederick Lawler <[email protected]> --- Changes in v2: - Add CONFIGFS_MAGIC to IMA documentation in patch 2 (per shashiko) - Update cover letter + commit message as suggested - Link to v1: https://lore.kernel.org/r/[email protected] --- Frederick Lawler (2): configfs: move CONFIGFS_MAGIC definition to magic.h ima: don't measure/appraise files on configfs Documentation/ABI/testing/ima_policy | 3 +++ fs/configfs/mount.c | 4 +--- include/uapi/linux/magic.h | 1 + security/integrity/ima/ima_policy.c | 7 ++++++- 4 files changed, 11 insertions(+), 4 deletions(-) --- base-commit: f1e10b10874051e4d99911dae0dd7b75a9f8ae66 change-id: 20260818-configfs-a248c410b083 Best regards, -- Frederick Lawler <[email protected]>
