Yanming reported a kernel bug in Bugzilla kernel [1], which can be reproduced. The bug message is:

The kernel message is shown below:

kernel BUG at fs/inode.c:611! Call Trace: evict+0x282/0x4e0 __dentry_kill+0x2b2/0x4d0 dput+0x2dd/0x720 do_renameat2+0x596/0x970 __x64_sys_rename+0x78/0x90 do_syscall_64+0x3b/0x90

[1] https://bugzilla.kernel.org/show_bug.cgi?id=215895

The bug is due to fuzzed inode has both inline_data and encrypted flags. During f2fs_evict_inode(), as the inode was deleted by rename(), it will cause inline data conversion due to conflicting flags. The page cache will be polluted and the panic will be triggered in clear_inode().

Try fixing the bug by doing more sanity checks for inline data inode in sanity_check_inode().

Cc: stable@vger.kernel.org Reported-by: Ming Yan yanming@tju.edu.cn Signed-off-by: Chao Yu chao.yu@oppo.com --- v4: - introduce and use f2fs_post_read_required_ondisk() only for sanity_check_inode(). fs/f2fs/f2fs.h | 15 ++++++++++++++- fs/f2fs/file.c | 2 +- fs/f2fs/inline.c | 11 ++++++++--- fs/f2fs/inode.c | 3 +-- fs/f2fs/namei.c | 2 +- 5 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 7faf230f101f..65442ab03d32 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4039,7 +4039,7 @@ extern struct kmem_cache *f2fs_inode_entry_slab; /* * inline.c */ -bool f2fs_may_inline_data(struct inode *inode); +bool f2fs_may_inline_data(struct inode *inode, bool sanity_check); bool f2fs_may_inline_dentry(struct inode *inode); void f2fs_do_read_inline_data(struct page *page, struct page *ipage); void f2fs_truncate_inline_inode(struct inode *inode, @@ -4141,6 +4141,19 @@ static inline void f2fs_set_encrypted_inode(struct inode *inode) #endif }

+static inline bool f2fs_post_read_required_ondisk(struct inode *inode) +{ + /* + * used by sanity_check_inode(), when disk layout fields has not + * been synchronized to inmem fields. + */ + if (S_ISREG(inode->i_mode) && (file_is_encrypt(inode) || + F2FS_I(inode)->i_flags & F2FS_COMPR_FL || + file_is_verity(inode))) + return true; + + return false; +} /* * Returns true if the reads of the inode's data need to undergo some * postprocessing step, like decryption or authenticity verification. diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 0a554730d2c4..73ba1c6dceaa 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -796,7 +796,7 @@ int f2fs_truncate(struct inode *inode) return err;

/* we should check inline_data size */ - if (!f2fs_may_inline_data(inode)) { + if (!f2fs_may_inline_data(inode, false)) { err = f2fs_convert_inline_inode(inode); if (err) return err; diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index a578bf83b803..331ecd8af80c 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -14,7 +14,7 @@ #include "node.h" #include <trace/events/f2fs.h>

-bool f2fs_may_inline_data(struct inode *inode) +bool f2fs_may_inline_data(struct inode *inode, bool sanity_check) { if (f2fs_is_atomic_file(inode)) return false; @@ -25,8 +25,13 @@ bool f2fs_may_inline_data(struct inode *inode) if (i_size_read(inode) > MAX_INLINE_DATA(inode)) return false;

- if (f2fs_post_read_required(inode)) - return false; + if (sanity_check) { + if (f2fs_post_read_required_ondisk(inode)) + return false; + } else { + if (f2fs_post_read_required(inode)) + return false; + }

return true; } diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 2fce8fa0dac8..3384100dde0b 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -276,8 +276,7 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) } }

- if (f2fs_has_inline_data(inode) && - (!S_ISREG(inode->i_mode) && !S_ISLNK(inode->i_mode))) { + if (f2fs_has_inline_data(inode) && !f2fs_may_inline_data(inode, true)) { set_sbi_flag(sbi, SBI_NEED_FSCK); f2fs_warn(sbi, "%s: inode (ino=%lx, mode=%u) should not have inline_data, run fsck to fix", __func__, inode->i_ino, inode->i_mode); diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index c549acb52ac4..514088f707ed 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -89,7 +89,7 @@ static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns, if (test_opt(sbi, INLINE_XATTR)) set_inode_flag(inode, FI_INLINE_XATTR);

- if (test_opt(sbi, INLINE_DATA) && f2fs_may_inline_data(inode)) + if (test_opt(sbi, INLINE_DATA) && f2fs_may_inline_data(inode, false)) set_inode_flag(inode, FI_INLINE_DATA); if (f2fs_may_inline_dentry(inode)) set_inode_flag(inode, FI_INLINE_DENTRY);