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| author | Deepanshu Kartikey <kartikey406@gmail.com> | 2026-03-31 09:47:21 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-22 13:30:52 +0200 |
| commit | 41de342278ae025c99cc8d33648773f05e306cf1 (patch) | |
| tree | 8be511e6d040dfe88a9f697b52ef0c04044df26f | |
| parent | 2eeae47a438694408189138048a786be99954032 (diff) | |
| download | linux-stable-41de342278ae025c99cc8d33648773f05e306cf1.tar.gz linux-stable-41de342278ae025c99cc8d33648773f05e306cf1.zip | |
nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map
commit 4a4e0328edd9e9755843787d28f16dd4165f8b48 upstream.
The DAT inode's btree node cache (i_assoc_inode) is initialized lazily
during btree operations. However, nilfs_mdt_save_to_shadow_map()
assumes i_assoc_inode is already initialized when copying dirty pages
to the shadow map during GC.
If NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before
any btree operation has occurred on the DAT inode, i_assoc_inode is
NULL leading to a general protection fault.
Fix this by calling nilfs_attach_btree_node_cache() on the DAT inode
in nilfs_dat_read() at mount time, ensuring i_assoc_inode is always
initialized before any GC operation can use it.
Reported-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4b4093b1f24ad789bf37
Tested-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com
Fixes: e897be17a441 ("nilfs2: fix lockdep warnings in page operations for btree nodes")
Signed-off-by: Deepanshu Kartikey <Kartikey406@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nilfs2/dat.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c index 674380837ab9..888dc1831c86 100644 --- a/fs/nilfs2/dat.c +++ b/fs/nilfs2/dat.c @@ -524,6 +524,9 @@ int nilfs_dat_read(struct super_block *sb, size_t entry_size, if (err) goto failed; + err = nilfs_attach_btree_node_cache(dat); + if (err) + goto failed; err = nilfs_read_inode_common(dat, raw_inode); if (err) goto failed; |