Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid migrating empty section It reports a bug from device w/ zufs: F2FS-fs (dm-64): Inconsistent segment (173822) type [1, 0] in SSA and SIT F2FS-fs (dm-64): Stopped filesystem due to reason: 4 Thread A Thread B - f2fs_expand_inode_data - f2fs_allocate_pinning_section - f2fs_gc_range - do_garbage_collect w/ segno #x - writepage - f2fs_allocate_data_block - new_curseg - allocate segno #x The root cause is: fallocate on pinning file may race w/ block allocation as above, result in do_garbage_collect() from fallocate() may migrate segment which is just allocated by a log, the log will update segment type in its in-memory structure, however GC will get segment type from on-disk SSA block, once segment type changes by log, we can detect such inconsistency, then shutdown filesystem. In this case, on-disk SSA shows type of segno #173822 is 1 (SUM_TYPE_NODE), however segno #173822 was just allocated as data type segment, so in-memory SIT shows type of segno #173822 is 0 (SUM_TYPE_DATA). Change as below to fix this issue: - check whether current section is empty before gc - add sanity checks on do_garbage_collect() to avoid any race case, result in migrating segment used by log. - btw, it fixes misc issue in printed logs: "SSA and SIT" -> "SIT and SSA".
Product status
9703d69d9d153bb230711d0d577454552aeb13d4 (git) before eec1589be36fcf7440755703e4faeee2c01e360b
9703d69d9d153bb230711d0d577454552aeb13d4 (git) before d625a2b08c089397d3a03bff13fa8645e4ec7a01
40d76c393cca83938b11eb7ca8983aa3cd0ed69b (git)
6.9
Any version before 6.9
6.17.3 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/eec1589be36fcf7440755703e4faeee2c01e360b
git.kernel.org/...c/d625a2b08c089397d3a03bff13fa8645e4ec7a01
