Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH 1/3] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() | Date | Fri, 26 Jul 2019 11:36:55 +0800 |
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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.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- fs/ocfs2/xattr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 385f3aaa2448..f690502daf3c 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -2154,8 +2154,10 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc, } } ocfs2_xa_wipe_namevalue(loc); - } else - ocfs2_xa_add_entry(loc, name_hash); + } else { + rc = -EINVAL; + goto out; + } /* * If we get here, we have a blank entry. Fill it. We grow our -- 2.17.0
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