| Message ID | 20241202171304.5430-1-leocstone@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [f2fs-dev,v3] f2fs: Add check for deleted inode | expand |
On 2024/12/3 1:12, Leo Stone wrote: > The syzbot reproducer mounts a f2fs image, then tries to unlink an > existing file. However, the unlinked file already has a link count of 0 > when it is read for the first time in do_read_inode(). > > Add a check to sanity_check_inode() for i_nlink == 0. > > Reported-by: syzbot+b01a36acd7007e273a83@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=b01a36acd7007e273a83 > Fixes: 39a53e0ce0df ("f2fs: add superblock and major in-memory structure") > Signed-off-by: Leo Stone <leocstone@gmail.com> Reviewed-by: Chao Yu <chao@kernel.org> Thanks,
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 1ed86df343a5..65f1dc32f173 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -372,6 +372,12 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) return false; } + if (inode->i_nlink == 0) { + f2fs_warn(sbi, "%s: inode (ino=%lx) has a link count of 0", + __func__, inode->i_ino); + return false; + } + return true; }
The syzbot reproducer mounts a f2fs image, then tries to unlink an existing file. However, the unlinked file already has a link count of 0 when it is read for the first time in do_read_inode(). Add a check to sanity_check_inode() for i_nlink == 0. Reported-by: syzbot+b01a36acd7007e273a83@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b01a36acd7007e273a83 Fixes: 39a53e0ce0df ("f2fs: add superblock and major in-memory structure") Signed-off-by: Leo Stone <leocstone@gmail.com> --- v3: Correct "Fixes" line again. Sorry for my confusion. v2: https://lore.kernel.org/linux-f2fs-devel/c0998223-6141-40e1-be08-d79bfc28eb0a@kernel.org/T/ v1: https://lore.kernel.org/all/20241124010459.23283-1-leocstone@gmail.com/T/ --- fs/f2fs/inode.c | 6 ++++++ 1 file changed, 6 insertions(+)