From 8c1621bedea53aa77ac39bbda26e86592d6dde5b Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 7 Feb 2019 18:40:59 +0100
Subject: sys/linux: prohibit EXT4_IOC_RESIZE_FS

When we run with sandbox=none, test program can do EXT4_IOC_RESIZE_FS which
shrinks rootfs basically to 0. This breaks the machine as all tests then fail with:

failed to create temp dir: mkdir syzkaller-testdir077269498: no space left on device

This is the most common source of "lost connection" crashes overall and
they are not actually kernel bugs.

Prohibit EXT4_IOC_RESIZE_FS for now.
Alternatively we can mount tmpfs with sandbox=none.

Update #971
---
 executor/syscalls.h | 5 -----
 1 file changed, 5 deletions(-)

(limited to 'executor/syscalls.h')

diff --git a/executor/syscalls.h b/executor/syscalls.h
index a270584e0..4164be810 100644
--- a/executor/syscalls.h
+++ b/executor/syscalls.h
@@ -2138,7 +2138,6 @@ const call_t syscalls[] = {
     {"ioctl$EXT4_IOC_MIGRATE", 54},
     {"ioctl$EXT4_IOC_MOVE_EXT", 54},
     {"ioctl$EXT4_IOC_PRECACHE_EXTENTS", 54},
-    {"ioctl$EXT4_IOC_RESIZE_FS", 54},
     {"ioctl$EXT4_IOC_SETFLAGS", 54},
     {"ioctl$EXT4_IOC_SWAP_BOOT", 54},
     {"ioctl$FIBMAP", 54},
@@ -4713,7 +4712,6 @@ const call_t syscalls[] = {
     {"ioctl$EXT4_IOC_MIGRATE", 16},
     {"ioctl$EXT4_IOC_MOVE_EXT", 16},
     {"ioctl$EXT4_IOC_PRECACHE_EXTENTS", 16},
-    {"ioctl$EXT4_IOC_RESIZE_FS", 16},
     {"ioctl$EXT4_IOC_SETFLAGS", 16},
     {"ioctl$EXT4_IOC_SWAP_BOOT", 16},
     {"ioctl$FIBMAP", 16},
@@ -7281,7 +7279,6 @@ const call_t syscalls[] = {
     {"ioctl$EXT4_IOC_MIGRATE", 54},
     {"ioctl$EXT4_IOC_MOVE_EXT", 54},
     {"ioctl$EXT4_IOC_PRECACHE_EXTENTS", 54},
-    {"ioctl$EXT4_IOC_RESIZE_FS", 54},
     {"ioctl$EXT4_IOC_SETFLAGS", 54},
     {"ioctl$EXT4_IOC_SWAP_BOOT", 54},
     {"ioctl$FIBMAP", 54},
@@ -9802,7 +9799,6 @@ const call_t syscalls[] = {
     {"ioctl$EXT4_IOC_MIGRATE", 29},
     {"ioctl$EXT4_IOC_MOVE_EXT", 29},
     {"ioctl$EXT4_IOC_PRECACHE_EXTENTS", 29},
-    {"ioctl$EXT4_IOC_RESIZE_FS", 29},
     {"ioctl$EXT4_IOC_SETFLAGS", 29},
     {"ioctl$EXT4_IOC_SWAP_BOOT", 29},
     {"ioctl$FIBMAP", 29},
@@ -12316,7 +12312,6 @@ const call_t syscalls[] = {
     {"ioctl$EXT4_IOC_MIGRATE", 54},
     {"ioctl$EXT4_IOC_MOVE_EXT", 54},
     {"ioctl$EXT4_IOC_PRECACHE_EXTENTS", 54},
-    {"ioctl$EXT4_IOC_RESIZE_FS", 54},
     {"ioctl$EXT4_IOC_SETFLAGS", 54},
     {"ioctl$EXT4_IOC_SWAP_BOOT", 54},
     {"ioctl$FIBMAP", 54},
-- 
cgit mrf-deployment