From 2976b10f05bd7f6dab9f9e7524451ddfed656a89 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Thu, 20 Jun 2013 11:36:28 +0200 Subject: [PATCH] perf: Disable monitoring on setuid processes for regular users There was a a bug in setup_new_exec(), whereby the test to disabled perf monitoring was not correct because the new credentials for the process were not yet committed and therefore the get_dumpable() test was never firing. The patch fixes the problem by moving the perf_event test until after the credentials are committed. Signed-off-by: Stephane Eranian Tested-by: Jiri Olsa Acked-by: Peter Zijlstra Cc: Signed-off-by: Ingo Molnar --- fs/exec.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 643019585574..ffd7a813ad3d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1135,13 +1135,6 @@ void setup_new_exec(struct linux_binprm * bprm) set_dumpable(current->mm, suid_dumpable); } - /* - * Flush performance counters when crossing a - * security domain: - */ - if (!get_dumpable(current->mm)) - perf_event_exit_task(current); - /* An exec changes our domain. We are no longer part of the thread group */ @@ -1205,6 +1198,15 @@ void install_exec_creds(struct linux_binprm *bprm) commit_creds(bprm->cred); bprm->cred = NULL; + + /* + * Disable monitoring for regular users + * when executing setuid binaries. Must + * wait until new credentials are committed + * by commit_creds() above + */ + if (get_dumpable(current->mm) != SUID_DUMP_USER) + perf_event_exit_task(current); /* * cred_guard_mutex must be held at least to this point to prevent * ptrace_attach() from altering our determination of the task's