Messages in this thread | | | Date | Fri, 30 Dec 2022 11:17:13 +0400 | Subject | Re: [PATCH] fs/ntfs3: Fix slab-out-of-bounds read in hdr_delete_de() | From | Konstantin Komarov <> |
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On 12.12.2022 05:31, Zeng Heng wrote: > Here is a BUG report from syzbot: > > BUG: KASAN: slab-out-of-bounds in hdr_delete_de+0xe0/0x150 fs/ntfs3/index.c:806 > Read of size 16842960 at addr ffff888079cc0600 by task syz-executor934/3631 > > Call Trace: > memmove+0x25/0x60 mm/kasan/shadow.c:54 > hdr_delete_de+0xe0/0x150 fs/ntfs3/index.c:806 > indx_delete_entry+0x74f/0x3670 fs/ntfs3/index.c:2193 > ni_remove_name+0x27a/0x980 fs/ntfs3/frecord.c:2910 > ntfs_unlink_inode+0x3d4/0x720 fs/ntfs3/inode.c:1712 > ntfs_rename+0x41a/0xcb0 fs/ntfs3/namei.c:276 > > Before using the meta-data in struct INDEX_HDR, we need to > check index header valid or not. Otherwise, the corruptedi > (or malicious) fs image can cause out-of-bounds access which > could make kernel panic. > > Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") > Reported-by: syzbot+9c2811fd56591639ff5f@syzkaller.appspotmail.com > Signed-off-by: Zeng Heng <zengheng4@huawei.com> > --- > fs/ntfs3/fslog.c | 2 +- > fs/ntfs3/index.c | 4 ++++ > fs/ntfs3/ntfs_fs.h | 1 + > 3 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c > index 0d611a6c5511..0de2bbb42721 100644 > --- a/fs/ntfs3/fslog.c > +++ b/fs/ntfs3/fslog.c > @@ -2597,7 +2597,7 @@ static int read_next_log_rec(struct ntfs_log *log, struct lcb *lcb, u64 *lsn) > return find_log_rec(log, *lsn, lcb); > } > > -static inline bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes) > +bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes) > { > __le16 mask; > u32 min_de, de_off, used, total; > diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c > index 440328147e7e..6f5d8dd6659d 100644 > --- a/fs/ntfs3/index.c > +++ b/fs/ntfs3/index.c > @@ -798,6 +798,10 @@ static inline struct NTFS_DE *hdr_delete_de(struct INDEX_HDR *hdr, > u32 off = PtrOffset(hdr, re); > int bytes = used - (off + esize); > > + /* check INDEX_HDR valid before using INDEX_HDR */ > + if (!check_index_header(hdr, le32_to_cpu(hdr->total))) > + return NULL; > + > if (off >= used || esize < sizeof(struct NTFS_DE) || > bytes < sizeof(struct NTFS_DE)) > return NULL; > diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h > index 2c791222c4e2..c5c022fef4e0 100644 > --- a/fs/ntfs3/ntfs_fs.h > +++ b/fs/ntfs3/ntfs_fs.h > @@ -574,6 +574,7 @@ int ni_rename(struct ntfs_inode *dir_ni, struct ntfs_inode *new_dir_ni, > bool ni_is_dirty(struct inode *inode); > > /* Globals from fslog.c */ > +bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes); > int log_replay(struct ntfs_inode *ni, bool *initialized); > > /* Globals from fsntfs.c */ Thanks for patch, applied!
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