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author | Jia-Ju Bai <baijiaju1990@gmail.com> | 2019-10-07 03:57:50 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-10-08 01:47:19 +0300 |
commit | 56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d (patch) | |
tree | 3fe025b19f43bfe824b95256f2ad92a682cb754c /fs/ocfs2 | |
parent | 7a243c82ea527cd1da47381ad9cd646844f3b693 (diff) | |
download | linux-56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d.tar.xz |
fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()
In ocfs2_xa_prepare_entry(), there is an if statement on line 2136 to
check whether loc->xl_entry is NULL:
if (loc->xl_entry)
When loc->xl_entry is NULL, it is used on line 2158:
ocfs2_xa_add_entry(loc, name_hash);
loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
and line 2164:
ocfs2_xa_add_namevalue(loc, xi);
loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
loc->xl_entry->xe_name_len = xi->xi_name_len;
Thus, possible null-pointer dereferences may occur.
To fix these bugs, if loc-xl_entry is NULL, ocfs2_xa_prepare_entry()
abnormally returns with -EINVAL.
These bugs are found by a static analysis tool STCheck written by us.
[akpm@linux-foundation.org: remove now-unused ocfs2_xa_add_entry()]
Link: http://lkml.kernel.org/r/20190726101447.9153-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2')
-rw-r--r-- | fs/ocfs2/xattr.c | 56 |
1 files changed, 23 insertions, 33 deletions
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 90c830e3758e..d8507972ee13 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -1490,18 +1490,6 @@ static int ocfs2_xa_check_space(struct ocfs2_xa_loc *loc, return loc->xl_ops->xlo_check_space(loc, xi); } -static void ocfs2_xa_add_entry(struct ocfs2_xa_loc *loc, u32 name_hash) -{ - loc->xl_ops->xlo_add_entry(loc, name_hash); - loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash); - /* - * We can't leave the new entry's xe_name_offset at zero or - * add_namevalue() will go nuts. We set it to the size of our - * storage so that it can never be less than any other entry. - */ - loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size); -} - static void ocfs2_xa_add_namevalue(struct ocfs2_xa_loc *loc, struct ocfs2_xattr_info *xi) { @@ -2133,29 +2121,31 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc, if (rc) goto out; - if (loc->xl_entry) { - if (ocfs2_xa_can_reuse_entry(loc, xi)) { - orig_value_size = loc->xl_entry->xe_value_size; - rc = ocfs2_xa_reuse_entry(loc, xi, ctxt); - if (rc) - goto out; - goto alloc_value; - } + if (!loc->xl_entry) { + rc = -EINVAL; + goto out; + } - if (!ocfs2_xattr_is_local(loc->xl_entry)) { - orig_clusters = ocfs2_xa_value_clusters(loc); - rc = ocfs2_xa_value_truncate(loc, 0, ctxt); - if (rc) { - mlog_errno(rc); - ocfs2_xa_cleanup_value_truncate(loc, - "overwriting", - orig_clusters); - goto out; - } + if (ocfs2_xa_can_reuse_entry(loc, xi)) { + orig_value_size = loc->xl_entry->xe_value_size; + rc = ocfs2_xa_reuse_entry(loc, xi, ctxt); + if (rc) + goto out; + goto alloc_value; + } + + if (!ocfs2_xattr_is_local(loc->xl_entry)) { + orig_clusters = ocfs2_xa_value_clusters(loc); + rc = ocfs2_xa_value_truncate(loc, 0, ctxt); + if (rc) { + mlog_errno(rc); + ocfs2_xa_cleanup_value_truncate(loc, + "overwriting", + orig_clusters); + goto out; } - ocfs2_xa_wipe_namevalue(loc); - } else - ocfs2_xa_add_entry(loc, name_hash); + } + ocfs2_xa_wipe_namevalue(loc); /* * If we get here, we have a blank entry. Fill it. We grow our |