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| author | ZhangPeng <zhangpeng362@huawei.com> | 2022-11-25 10:21:59 +0000 |
|---|---|---|
| committer | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2023-03-27 16:59:08 +0400 |
| commit | 254e69f284d7270e0abdc023ee53b71401c3ba0c (patch) | |
| tree | 01da2b2562c6ac46e0f8d9136226d96cf1df116d /fs/ntfs3 | |
| parent | e6c3cef24cb0d045f99d5cb039b344874e3cfd74 (diff) | |
| download | linux-254e69f284d7270e0abdc023ee53b71401c3ba0c.tar.gz | |
fs/ntfs3: Fix null-ptr-deref on inode->i_op in ntfs_lookup()
Syzbot reported a null-ptr-deref bug:
ntfs3: loop0: Different NTFS' sector size (1024) and media sector size
(512)
ntfs3: loop0: Mark volume as dirty due to NTFS errors
general protection fault, probably for non-canonical address
0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
RIP: 0010:d_flags_for_inode fs/dcache.c:1980 [inline]
RIP: 0010:__d_add+0x5ce/0x800 fs/dcache.c:2796
Call Trace:
<TASK>
d_splice_alias+0x122/0x3b0 fs/dcache.c:3191
lookup_open fs/namei.c:3391 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x10e6/0x2df0 fs/namei.c:3688
do_filp_open+0x264/0x4f0 fs/namei.c:3718
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_open fs/open.c:1334 [inline]
__se_sys_open fs/open.c:1330 [inline]
__x64_sys_open+0x221/0x270 fs/open.c:1330
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
If the MFT record of ntfs inode is not a base record, inode->i_op can be
NULL. And a null-ptr-deref may happen:
ntfs_lookup()
dir_search_u() # inode->i_op is set to NULL
d_splice_alias()
__d_add()
d_flags_for_inode() # inode->i_op->get_link null-ptr-deref
Fix this by adding a Check on inode->i_op before calling the
d_splice_alias() function.
Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation")
Reported-by: syzbot+a8f26a403c169b7593fe@syzkaller.appspotmail.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'fs/ntfs3')
| -rw-r--r-- | fs/ntfs3/namei.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c index 407fe92394e22..8d206770d8c6d 100644 --- a/fs/ntfs3/namei.c +++ b/fs/ntfs3/namei.c @@ -88,6 +88,16 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry, __putname(uni); } + /* + * Check for a null pointer + * If the MFT record of ntfs inode is not a base record, inode->i_op can be NULL. + * This causes null pointer dereference in d_splice_alias(). + */ + if (!IS_ERR(inode) && inode->i_op == NULL) { + iput(inode); + inode = ERR_PTR(-EINVAL); + } + return d_splice_alias(inode, dentry); } |