In the Linux kernel, the following vulnerability has been resolved:
nilfs2: do not force clear folio if buffer is referenced
Patch series "nilfs2: protect busy buffer heads from being force-cleared".
This series fixes the buffer head state inconsistency issues reported by
syzbot that occurs when the filesystem is corrupted and falls back to
read-only, and the associated buffer head use-after-free issue.
This patch (of 2):
Syzbot has reported that after nilfs2 detects filesystem corruption and
falls back to read-only, inconsistencies in the buffer state may occur.
One of the inconsistencies is that when nilfs2 calls mark_buffer_dirty()
to set a data or metadata buffer as dirty, but it detects that the buffer
is not in the uptodate state:
WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520
fs/buffer.c:1177
...
Call Trace:
nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598
nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73
nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344
nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
do_mkdirat+0x264/0x3a0 fs/namei.c:4280
__do_sys_mkdirat fs/namei.c:4295 [inline]
__se_sys_mkdirat fs/namei.c:4293 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The other is when nilfs_btree_pr...
CVE ID: CVE-2025-21722
Vendor: Linux, Linux
Product: Linux, Linux
EPSS Score: 0.02% (probability of being exploited)
EPSS Percentile: 1.85% (scored less or equal to compared to others)
EPSS Date: 2025-03-27 (when was this score calculated)