jfs: Fix fortify moan in symlink
JFS has in jfs_incore.h:
/* _inline may overflow into _inline_ea when needed */
/* _inline_ea may overlay the last part of
* file._xtroot if maxentry = XTROOTINITSLOT
*/
union {
struct {
/* 128: inline symlink */
unchar _inline[128];
/* 128: inline extended attr */
unchar _inline_ea[128];
};
unchar _inline_all[256];
and currently the symlink code copies into _inline;
if this is larger than 128 bytes it triggers a fortify warning of the
form:
memcpy: detected field-spanning write (size 132) of single field
"ip->i_link" at fs/jfs/namei.c:950 (size
18446744073709551615)
when it's actually OK.
Copy it into _inline_all instead.
Reported-by: syzbot+5fc38b2ddbbca7f5c680@syzkaller.appspotmail.com
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>