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authorJia-Ju Bai <baijiaju1990@gmail.com>2019-10-06 17:57:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-10-07 15:47:19 -0700
commit56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d (patch)
tree3fe025b19f43bfe824b95256f2ad92a682cb754c /fs/ocfs2/xattr.c
parent7a243c82ea527cd1da47381ad9cd646844f3b693 (diff)
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/xattr.c')
-rw-r--r--fs/ocfs2/xattr.c56
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