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[6/6] sysvipc: Return EINVAL for invalid shmctl commands

Message ID 20200928144556.239160-6-adhemerval.zanella@linaro.org
State New
Headers show
Series [1/6] sysvipc: Fix SEM_STAT_ANY kernel argument pass [BZ #26637] | expand

Commit Message

Adhemerval Zanella Sept. 28, 2020, 2:45 p.m. UTC
It avoids regressions on possible future commands that might require
additional libc support.  The downside is new commands added by newer
kernels will need further glibc support.

Checked on x86_64-linux-gnu and i686-linux-gnu (Linux v4.15 and v5.4).
---
 sysdeps/unix/sysv/linux/shmctl.c | 41 ++++++++++++++++++++++++--------
 sysvipc/test-sysvshm.c           |  5 ++++
 2 files changed, 36 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/shmctl.c b/sysdeps/unix/sysv/linux/shmctl.c
index 1d19a798b1..98eae91482 100644
--- a/sysdeps/unix/sysv/linux/shmctl.c
+++ b/sysdeps/unix/sysv/linux/shmctl.c
@@ -88,25 +88,46 @@  __shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)
 {
 #if __IPC_TIME64
   struct kernel_shmid64_ds kshmid, *arg = NULL;
-  if (buf != NULL)
+#else
+  shmctl_arg_t *arg;
+#endif
+
+  switch (cmd)
     {
-      /* This is a Linux extension where kernel expects either a
-	 'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO).  */
-      if (cmd == IPC_INFO || cmd == SHM_INFO)
-	arg = (struct kernel_shmid64_ds *) buf;
-      else
+    case IPC_RMID:
+      arg = NULL;
+      break;
+
+    case IPC_SET:
+    case IPC_STAT:
+    case SHM_STAT:
+#if __IPC_TIME64
+      if (buf != NULL)
 	{
 	  shmid64_to_kshmid64 (buf, &kshmid);
 	  arg = &kshmid;
 	}
-    }
 # ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
-  if (cmd == IPC_SET)
-    arg->shm_perm.mode *= 0x10000U;
+      if (cmd == IPC_SET)
+        arg->msg_perm.mode *= 0x10000U;
 # endif
 #else
-  shmctl_arg_t *arg = buf;
+      arg = buf;
 #endif
+      break;
+
+    case IPC_INFO:
+    case SHM_INFO:
+      /* This is a Linux extension where kernel expects either a
+	 'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO).  */
+      arg = (__typeof__ (arg)) buf;
+      break;
+
+    default:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
 
   int ret = shmctl_syscall (shmid, cmd, arg);
   if (ret < 0)
diff --git a/sysvipc/test-sysvshm.c b/sysvipc/test-sysvshm.c
index f083fd280b..a1b8b4823e 100644
--- a/sysvipc/test-sysvshm.c
+++ b/sysvipc/test-sysvshm.c
@@ -25,6 +25,8 @@ 
 #include <sys/ipc.h>
 #include <sys/shm.h>
 
+#include <test-sysvipc.h>
+
 #include <support/support.h>
 #include <support/check.h>
 #include <support/temp_file.h>
@@ -81,6 +83,9 @@  do_test (void)
       FAIL_EXIT1 ("shmget failed (errno=%d)", errno);
     }
 
+  TEST_COMPARE (shmctl (shmid, first_shm_invalid_cmd (), NULL), -1);
+  TEST_COMPARE (errno, EINVAL);
+
   /* Get shared memory kernel information and do some sanity checks.  */
   struct shmid_ds shminfo;
   if (shmctl (shmid, IPC_STAT, &shminfo) == -1)