From: Austin Kim <austin.kim@xxxxxxx> audit_log_start() may return NULL in below cases: - when audit is not initialized. - when audit backlog limit exceeds. After the call to audit_log_start() is made and then possible NULL audit buffer argument is passed to audit_log_*() functions, audit_log_*() functions return immediately in case of a NULL audit buffer argument. But it is optimal to return early when audit_log_start() returns NULL, because it is not necessary for audit_log_*() functions to be called with NULL audit buffer argument. So add exception handling for possible NULL audit buffers where return value can be handled from callers. Signed-off-by: Austin Kim <austin.kim@xxxxxxx> --- security/selinux/hooks.c | 4 ++++ security/selinux/ss/services.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b0032c42333e..9e84e6635f2f 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3325,6 +3325,8 @@ static int selinux_inode_setxattr(struct user_namespace *mnt_userns, } ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + return rc; audit_log_format(ab, "op=setxattr invalid_context="); audit_log_n_untrustedstring(ab, value, audit_size); audit_log_end(ab); @@ -6552,6 +6554,8 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + return error; audit_log_format(ab, "op=fscreate invalid_context="); audit_log_n_untrustedstring(ab, value, audit_size); audit_log_end(ab); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index d84c77f370dc..e5f1b2757a83 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1673,6 +1673,8 @@ static int compute_sid_handle_invalid_context( if (context_struct_to_string(policydb, newcontext, &n, &nlen)) goto out; ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; audit_log_format(ab, "op=security_compute_sid invalid_context="); /* no need to record the NUL with untrusted strings */ -- 2.20.1
