High · published July 23, 2026
In the Linux kernel, the following vulnerability has been resolved:
xfs: resample the data fork mapping after cycling ILOCK
xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode,
a data fork mapping, and a cow fork mapping. Unfortunately, these two
helpers cycle the ILOCK to grab a transaction, which means that the
mappings are stale as soon as we reacquire the ILOCK. Currently we
refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but
we don't refresh the data fork mapping beforehand, which means that the
xfs_bmap_trim_cow in that function queries the refcount btree about the
wrong physical blocks and returns an inaccurate value in *shared.
If *shared is now false, the directio write proceeds with a stale data
fork mapping. Fix this by querying the data fork mapping if the
sequence counter changes across the ILOCK cycle.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 4.11, < 5.15.212 | 5.15.212 |
| linux/linux_kernel | ≥ 5.16, < 6.1.178 | 6.1.178 |
| linux/linux_kernel | ≥ 6.2, < 6.6.145 | 6.6.145 |
| linux/linux_kernel | ≥ 6.7, < 6.12.96 | 6.12.96 |
| linux/linux_kernel | ≥ 6.13, < 6.18.39 | 6.18.39 |
| linux/linux_kernel | ≥ 6.19, < 7.1.4 | 7.1.4 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |