md/md-bitmap: fix wrong bitmap_limit for clustermd when write sb

Summary

In the Linux kernel, the following vulnerability has been resolved: md/md-bitmap: fix wrong bitmap_limit for clustermd when write sb In clustermd, separate write-intent-bitmaps are used for each cluster node: 0 4k 8k 12k ------------------------------------------------------------------- | idle | md super | bm super [0] + bits | | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] | | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits | | bm bits [3, contd] | | | So in node 1, pg_index in __write_sb_page() could equal to bitmap->storage.file_pages. Then bitmap_limit will be calculated to 0. md_super_write() will be called with 0 size. That means the first 4k sb area of node 1 will never be updated through filemap_write_page(). This bug causes hang of mdadm/clustermd_tests/01r1_Grow_resize. Here use (pg_index % bitmap->storage.file_pages) to make calculation of bitmap_limit correct.

Timeline

1. Apr 16, 2025, 2:13 PM UTCCVE published
2. Oct 15, 2026, 9:44 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 15, 2026, 9:51 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 655cc01889fa9b65441922565cddee64af49e6d6 · fixed in 5eaf57fdfa37c869e61e9908e03edd707f9145b8; From ab99a87542f194f28e2364a42afbf9fb48b1c724 · fixed in 60196f92bbc7901eb5cfa5d456651b87ea50a4a3; From ab99a87542f194f28e2364a42afbf9fb48b1c724 · fixed in bc3a9788961631359527763d7e1fcf26554c7cb1; From ab99a87542f194f28e2364a42afbf9fb48b1c724 · fixed in 6130825f34d41718c98a9b1504a79a23e379701e; From 6.6.44 · fixed in 6.6.157; From 6.10.3 · fixed in 6.11

• Linux Linux

  6.11

• KernelLinux

  fixed in 6.6.157; From 6.7.0 · fixed in 6.12.46; From 6.11.0 · fixed in 6.14.2

References 4