diff mbox

[PULL,10/15] linux-user: return EINVAL from prctl(PR_*_SECCOMP)

Message ID a8b154a637b586441bad42259a8a9b9619cd117c.1511212753.git.riku.voipio@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Riku Voipio Nov. 20, 2017, 9:21 p.m. UTC 
From: James Cowgill <james.cowgill@mips.com>

If an application tries to install a seccomp filter using
prctl(PR_SET_SECCOMP), the filter is likely for the target instead of the host
architecture. This will probably cause qemu to be immediately killed when it
executes another syscall.

Prevent this from happening by returning EINVAL from both seccomp prctl
calls. This is the error returned by the kernel when seccomp support is
disabled.

Fixes: https://bugs.launchpad.net/qemu/+bug/1726394
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: James Cowgill <james.cowgill@mips.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 linux-user/syscall.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 84e123b67b..f31b853bb7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -10505,6 +10505,12 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             break;
         }
 #endif
+        case PR_GET_SECCOMP:
+        case PR_SET_SECCOMP:
+            /* Disable seccomp to prevent the target disabling syscalls we
+             * need. */
+            ret = -TARGET_EINVAL;
+            break;
         default:
             /* Most prctl options have no pointer arguments */
             ret = get_errno(prctl(arg1, arg2, arg3, arg4, arg5));