Commit e3489f8974e1 ("selinux: kill selinux_sb_get_mnt_opts()")
introduced a NULL check on the context after a successful call to
security_sid_to_context(). This is on the one hand redundant after
checking for success and on the other hand insufficient on an actual
NULL pointer, since the context is passed to seq_escape() leading to a
call of strlen() on it.
Reported by Clang analyzer:
In file included from security/selinux/hooks.c:28:
In file included from ./include/linux/tracehook.h:50:
In file included from ./include/linux/memcontrol.h:13:
In file included from ./include/linux/cgroup.h:18:
./include/linux/seq_file.h:136:25: warning: Null pointer passed as 1st argument to string length function [unix.cstring.NullArg]
seq_escape_mem(m, src, strlen(src), flags, esc);
^~~~~~~~~~~
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
security/selinux/hooks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1e69f88eb326..ac802b99d36c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1020,7 +1020,7 @@ static int show_sid(struct seq_file *m, u32 sid)
rc = security_sid_to_context(&selinux_state, sid,
&context, &len);
if (!rc) {
- bool has_comma = context && strchr(context, ',');
+ bool has_comma = strchr(context, ',');
seq_putc(m, '=');
if (has_comma)
--
2.35.1
