[PATCH v2] audit: free proctitle in context so it can be re-set by fork on exec_binprm

[Richard Guy Briggs <rgb@redhat.com>]

Between the actual process startup (fork systemd) and the executable file
replacement (exec), systemd sets a temporary file name (executable file
name in parentheses). If an auditable system call occurs at this point,
the audit context will latch the temporary process name into the cache.
This name will not change again. The patch clears proctitle into the
audit cache when the exec call is made, allowing the new process name to
be latched.

Suggested-by: Roman Dolgikh <rmd4work@mail.ru>
Link: https://github.com/user-attachments/files/20751461/fix_audit_proctitle.txt
Link: https://github.com/linux-audit/audit-kernel/issues/170
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
Changelog:
v2: simplified to call single use directly before need in audit_bimprm
---
 kernel/auditsc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6610e667c728..c12b5dfcb279 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2601,6 +2601,8 @@ void __audit_bprm(struct linux_binprm *bprm)
 {
 	struct audit_context *context = audit_context();
 
+	/* clear proctitle in audit context to allow replacement */
+	audit_proctitle_free(audit_context());
 	context->type = AUDIT_EXECVE;
 	context->execve.argc = bprm->argc;
 }
-- 
2.43.5