From: Paul Floyd <pjfloyd@wanadoo.fr>
Date: Sun, 31 Aug 2025 08:44:49 +0000 (+0200)
Subject: Bug 507867 - perf_event_open group_fd isn't checked
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d9ed6b6f29d217ce9b2c4ccebcc255574d4d55b5;p=thirdparty%2Fvalgrind.git

Bug 507867 - perf_event_open group_fd isn't checked
---

diff --git a/NEWS b/NEWS
index d9ac8bdcb..8b7f688f3 100644
--- a/NEWS
+++ b/NEWS
@@ -77,6 +77,7 @@ are not entered into bugzilla tend to get forgotten about or ignored.
 507721  Wire up illumos and Solaris mallinfo
 507853  faccessat and faccessat2 should handle AT_FDCWD and absolute paths
 507866  fanotify_mark dirfd isn't checked
+507867  perf_event_open group_fd isn't checked
 507868  futimesat doesn't handle AT_FDCWD
 507869  Various at syscalls don't check dirfd argument
 507873  Make fchmodat and fchmodat2 syscall wrappers accept AT_FDCWD
diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index a511ccfe2..fef23763f 100644
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -4155,6 +4155,8 @@ PRE(sys_stime)
 
 PRE(sys_perf_event_open)
 {
+   // int syscall(SYS_perf_event_open, struct perf_event_attr *attr,
+   //             pid_t pid, int cpu, int group_fd, unsigned long flags);
    struct vki_perf_event_attr *attr;
    PRINT("sys_perf_event_open ( %#" FMT_REGWORD "x, %ld, %ld, %ld, %#"
          FMT_REGWORD "x )", ARG1, SARG2, SARG3, SARG4, ARG5);
@@ -4167,6 +4169,13 @@ PRE(sys_perf_event_open)
                  (Addr)&attr->size, sizeof(attr->size) );
    PRE_MEM_READ( "perf_event_open(attr)",
                  (Addr)attr, attr->size );
+   if ((ARG5 & VKI_PERF_FLAG_FD_NO_GROUP) != VKI_PERF_FLAG_FD_NO_GROUP) {
+       if ((Int)SARG4 != -1) {
+          if (!ML_(fd_allowed)(SARG4, "perf_event_open", tid, False)) {
+             SET_STATUS_Failure(VKI_EBADF);
+          }
+       }
+   }
 }
 
 POST(sys_perf_event_open)
diff --git a/include/vki/vki-linux.h b/include/vki/vki-linux.h
index c31035cbb..1e04bdd48 100644
--- a/include/vki/vki-linux.h
+++ b/include/vki/vki-linux.h
@@ -3223,6 +3223,8 @@ struct vki_perf_event_attr {
 #define VKI_PERF_EVENT_IOC_ID           _VKI_IOR('$', 7, __vki_u64 *)
 #define VKI_PERF_EVENT_IOC_SET_BPF      _VKI_IOW('$', 8, __vki_u32)
 
+#define VKI_PERF_FLAG_FD_NO_GROUP       (1UL << 0)
+
 /*--------------------------------------------------------------------*/
 // From linux-2.6.32.4/include/linux/getcpu.h
 /*--------------------------------------------------------------------*/