diff options
| author | Edward Adam Davis <eadavis@qq.com> | 2024-12-09 07:56:52 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-12-19 04:04:44 +0100 |
| commit | 901ce9705fbb9f330ff1f19600e5daf9770b0175 (patch) | |
| tree | a38a2c084bbb309518e295d9ef6739a76fb64107 /fs/nilfs2 | |
| parent | zram: fix uninitialized ZRAM not releasing backing device (diff) | |
| download | linux-901ce9705fbb9f330ff1f19600e5daf9770b0175.tar.xz linux-901ce9705fbb9f330ff1f19600e5daf9770b0175.zip | |
nilfs2: prevent use of deleted inode
syzbot reported a WARNING in nilfs_rmdir. [1]
Because the inode bitmap is corrupted, an inode with an inode number that
should exist as a ".nilfs" file was reassigned by nilfs_mkdir for "file0",
causing an inode duplication during execution. And this causes an
underflow of i_nlink in rmdir operations.
The inode is used twice by the same task to unmount and remove directories
".nilfs" and "file0", it trigger warning in nilfs_rmdir.
Avoid to this issue, check i_nlink in nilfs_iget(), if it is 0, it means
that this inode has been deleted, and iput is executed to reclaim it.
[1]
WARNING: CPU: 1 PID: 5824 at fs/inode.c:407 drop_nlink+0xc4/0x110 fs/inode.c:407
...
Call Trace:
<TASK>
nilfs_rmdir+0x1b0/0x250 fs/nilfs2/namei.c:342
vfs_rmdir+0x3a3/0x510 fs/namei.c:4394
do_rmdir+0x3b5/0x580 fs/namei.c:4453
__do_sys_rmdir fs/namei.c:4472 [inline]
__se_sys_rmdir fs/namei.c:4470 [inline]
__x64_sys_rmdir+0x47/0x50 fs/namei.c:4470
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
Link: https://lkml.kernel.org/r/20241209065759.6781-1-konishi.ryusuke@gmail.com
Fixes: d25006523d0b ("nilfs2: pathname operations")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+9260555647a5132edd48@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9260555647a5132edd48
Tested-by: syzbot+9260555647a5132edd48@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/inode.c | 8 | ||||
| -rw-r--r-- | fs/nilfs2/namei.c | 5 |
2 files changed, 12 insertions, 1 deletions
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index cf9ba481ae37..b7d4105f37bf 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -544,8 +544,14 @@ struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root, inode = nilfs_iget_locked(sb, root, ino); if (unlikely(!inode)) return ERR_PTR(-ENOMEM); - if (!(inode->i_state & I_NEW)) + + if (!(inode->i_state & I_NEW)) { + if (!inode->i_nlink) { + iput(inode); + return ERR_PTR(-ESTALE); + } return inode; + } err = __nilfs_read_inode(sb, root, ino, inode); if (unlikely(err)) { diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 9b108052d9f7..1d836a5540f3 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -67,6 +67,11 @@ nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) inode = NULL; } else { inode = nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino); + if (inode == ERR_PTR(-ESTALE)) { + nilfs_error(dir->i_sb, + "deleted inode referenced: %lu", ino); + return ERR_PTR(-EIO); + } } return d_splice_alias(inode, dentry); |