[Bug libc/26637] New: semctl SEM_STAT_ANY fails to pass the buffer specified by the caller to the kernel

ldv at sourceware dot org sourceware-bugzilla@sourceware.org
Sun Sep 20 00:41:37 GMT 2020


https://sourceware.org/bugzilla/show_bug.cgi?id=26637

            Bug ID: 26637
           Summary: semctl SEM_STAT_ANY fails to pass the buffer specified
                    by the caller to the kernel
           Product: glibc
           Version: 2.32
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: ldv at sourceware dot org
                CC: drepper.fsp at gmail dot com
  Target Milestone: ---
             Flags: security-

The kernel receives garbage instead of union semun.buf address specified by the
caller.

$ git --no-pager grep -wc SEM_STAT_ANY sysdeps/unix/sysv/linux/semctl.c
sysdeps/unix/sysv/linux/semctl.c:2
$ git --no-pager grep -wc SEM_STAT sysdeps/unix/sysv/linux/semctl.c
sysdeps/unix/sysv/linux/semctl.c:8

A tentative fix:

diff --git a/sysdeps/unix/sysv/linux/semctl.c
b/sysdeps/unix/sysv/linux/semctl.c
index f131a26fc7..1cdabde8f2 100644
--- a/sysdeps/unix/sysv/linux/semctl.c
+++ b/sysdeps/unix/sysv/linux/semctl.c
@@ -102,6 +102,7 @@ semun64_to_ksemun64 (int cmd, union semun64 semun64,
       r.array = semun64.array;
       break;
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_STAT:
     case IPC_SET:
       r.buf = buf;
@@ -150,6 +151,7 @@ __semctl64 (int semid, int semnum, int cmd, ...)
     case IPC_STAT:      /* arg.buf */
     case IPC_SET:
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);
@@ -238,6 +240,7 @@ semun_to_semun64 (int cmd, union semun semun, struct
__semid64_ds *semid64)
       r.array = semun.array;
       break;
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_STAT:
     case IPC_SET:
       r.buf = semid64;
@@ -267,6 +270,7 @@ __semctl (int semid, int semnum, int cmd, ...)
     case IPC_STAT:      /* arg.buf */
     case IPC_SET:
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);
@@ -321,6 +325,7 @@ __semctl_mode16 (int semid, int semnum, int cmd, ...)
     case IPC_STAT:      /* arg.buf */
     case IPC_SET:
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);
@@ -354,6 +359,7 @@ __old_semctl (int semid, int semnum, int cmd, ...)
     case IPC_STAT:      /* arg.buf */
     case IPC_SET:
     case SEM_STAT:
+    case SEM_STAT_ANY:
     case IPC_INFO:      /* arg.__buf */
     case SEM_INFO:
       va_start (ap, cmd);

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