In the Linux kernel, the following vulnerability has been resolved: dm-integrity: fix NULL pointer dereference when the 'R' flag is used If the… (CVE-2026-99087)

The Linux kernel's dm-integrity device had a vulnerability where, if the SB_FLAG_DIRTY_BITMAP flag was set and the device was activated in 'R' mode, the dm_integrity_resume function would crash due to a NULL pointer dereference. This happened because the function tried to read a journal containing the bitmap that was not properly handled in this mode. The patch modifies dm-integrity to skip any writes to the device during dm_integrity_resume when activated in 'R' mode, preventing the crash.

The vulnerability causes a crash (NULL pointer dereference) in the Linux kernel's dm-integrity device under specific conditions, potentially leading to denial of service by device unavailability or kernel instability. There is no information about code execution or privilege escalation.

A patch has been applied to the Linux kernel to fix this issue by skipping writes during dm_integrity_resume when the device is activated in 'R' mode. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the input, so verify with the vendor advisory for current remediation guidance.