Date:   Fri, 17 Dec 2021 07:08:04 +0800
From:   kernel test robot <lkp@intel.com>
To:     Keno Fischer <keno@juliacomputing.com>,
        linux-kernel@vger.kernel.org
Cc:     kbuild-all@lists.01.org, gorcunov@openvz.org,
        khlebnikov@openvz.org, oleg@redhat.com, akpm@linux-foundation.org,
        keescook@chromium.org, tj@kernel.org, dbueso@suse.de,
        matthltc@us.ibm.com, kosaki.motohiro@jp.fujitsu.com
Subject: Re: [PATCH] c/r: prctl: Remove PR_SET_MM_EXE_FILE old file mapping
 restriction
Message-ID: <202112170623.8IdZgt6d-lkp@intel.com>
References: <20211215062342.GA1548576@juliacomputing.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
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In-Reply-To: <20211215062342.GA1548576@juliacomputing.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

Hi Keno,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linux/master]
[also build test WARNING on hnaz-mm/master linus/master v5.16-rc5 next-20211215]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Keno-Fischer/c-r-prctl-Remove-PR_SET_MM_EXE_FILE-old-file-mapping-restriction/20211215-142515
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 136057256686de39cc3a07c2e39ef6bc43003ff6
config: mips-randconfig-s031-20211216 (https://download.01.org/0day-ci/archive/20211217/202112170623.8IdZgt6d-lkp@intel.com/config)
compiler: mips64el-linux-gcc (GCC) 11.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/08f30df401c936e27733e3b37765c2b7d35fe0e7
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Keno-Fischer/c-r-prctl-Remove-PR_SET_MM_EXE_FILE-old-file-mapping-restriction/20211215-142515
        git checkout 08f30df401c936e27733e3b37765c2b7d35fe0e7
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=mips SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
   command-line: note: in included file:
   builtin:1:9: sparse: sparse: preprocessor token __ATOMIC_ACQUIRE redefined
   builtin:0:0: sparse: this was the original definition
   builtin:1:9: sparse: sparse: preprocessor token __ATOMIC_SEQ_CST redefined
   builtin:0:0: sparse: this was the original definition
   builtin:1:9: sparse: sparse: preprocessor token __ATOMIC_ACQ_REL redefined
   builtin:0:0: sparse: this was the original definition
   builtin:1:9: sparse: sparse: preprocessor token __ATOMIC_RELEASE redefined
   builtin:0:0: sparse: this was the original definition
>> kernel/fork.c:1215:22: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct file *old_exe_file @@     got struct file [noderef] __rcu *[assigned] __res @@
   kernel/fork.c:1215:22: sparse:     expected struct file *old_exe_file
   kernel/fork.c:1215:22: sparse:     got struct file [noderef] __rcu *[assigned] __res
   kernel/fork.c:1572:38: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct refcount_struct [usertype] *r @@     got struct refcount_struct [noderef] __rcu * @@
   kernel/fork.c:1572:38: sparse:     expected struct refcount_struct [usertype] *r
   kernel/fork.c:1572:38: sparse:     got struct refcount_struct [noderef] __rcu *
   kernel/fork.c:1581:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:1581:31: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:1581:31: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:1582:36: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const *q @@     got struct k_sigaction [noderef] __rcu * @@
   kernel/fork.c:1582:36: sparse:     expected void const *q
   kernel/fork.c:1582:36: sparse:     got struct k_sigaction [noderef] __rcu *
   kernel/fork.c:1583:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:1583:33: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:1583:33: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:1676:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct qspinlock *lock @@     got struct qspinlock [noderef] __rcu * @@
   kernel/fork.c:1676:9: sparse:     expected struct qspinlock *lock
   kernel/fork.c:1676:9: sparse:     got struct qspinlock [noderef] __rcu *
   kernel/fork.c:1995:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:1995:31: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:1995:31: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:1999:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:1999:33: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:1999:33: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2304:32: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct task_struct [noderef] __rcu *real_parent @@     got struct task_struct *task @@
   kernel/fork.c:2304:32: sparse:     expected struct task_struct [noderef] __rcu *real_parent
   kernel/fork.c:2304:32: sparse:     got struct task_struct *task
   kernel/fork.c:2313:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:2313:27: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:2313:27: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2362:54: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct list_head *head @@     got struct list_head [noderef] __rcu * @@
   kernel/fork.c:2362:54: sparse:     expected struct list_head *head
   kernel/fork.c:2362:54: sparse:     got struct list_head [noderef] __rcu *
   kernel/fork.c:2383:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:2383:29: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:2383:29: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2401:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:2401:29: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:2401:29: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2428:28: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct sighand_struct *sighand @@     got struct sighand_struct [noderef] __rcu *sighand @@
   kernel/fork.c:2428:28: sparse:     expected struct sighand_struct *sighand
   kernel/fork.c:2428:28: sparse:     got struct sighand_struct [noderef] __rcu *sighand
   kernel/fork.c:2456:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:2456:31: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:2456:31: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2458:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   kernel/fork.c:2458:33: sparse:     expected struct spinlock [usertype] *lock
   kernel/fork.c:2458:33: sparse:     got struct spinlock [noderef] __rcu *
   kernel/fork.c:2867:24: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct task_struct *[assigned] parent @@     got struct task_struct [noderef] __rcu *real_parent @@
   kernel/fork.c:2867:24: sparse:     expected struct task_struct *[assigned] parent
   kernel/fork.c:2867:24: sparse:     got struct task_struct [noderef] __rcu *real_parent
   kernel/fork.c:2948:43: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct refcount_struct const [usertype] *r @@     got struct refcount_struct [noderef] __rcu * @@
   kernel/fork.c:2948:43: sparse:     expected struct refcount_struct const [usertype] *r
   kernel/fork.c:2948:43: sparse:     got struct refcount_struct [noderef] __rcu *
   kernel/fork.c:2039:22: sparse: sparse: dereference of noderef expression
   kernel/fork.c: note: in included file (through include/uapi/asm-generic/bpf_perf_event.h, arch/mips/include/generated/uapi/asm/bpf_perf_event.h, ...):
   include/linux/ptrace.h:218:45: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct task_struct *new_parent @@     got struct task_struct [noderef] __rcu *parent @@
   include/linux/ptrace.h:218:45: sparse:     expected struct task_struct *new_parent
   include/linux/ptrace.h:218:45: sparse:     got struct task_struct [noderef] __rcu *parent
   include/linux/ptrace.h:218:62: sparse: sparse: incorrect type in argument 3 (different address spaces) @@     expected struct cred const *ptracer_cred @@     got struct cred const [noderef] __rcu *ptracer_cred @@
   include/linux/ptrace.h:218:62: sparse:     expected struct cred const *ptracer_cred
   include/linux/ptrace.h:218:62: sparse:     got struct cred const [noderef] __rcu *ptracer_cred
   kernel/fork.c:2360:59: sparse: sparse: dereference of noderef expression
   kernel/fork.c:2361:59: sparse: sparse: dereference of noderef expression

vim +1215 kernel/fork.c

3864601387cf419 Jiri Slaby        2011-05-26  1194  
35d7bdc86031a2c David Hildenbrand 2021-04-23  1195  /**
35d7bdc86031a2c David Hildenbrand 2021-04-23  1196   * replace_mm_exe_file - replace a reference to the mm's executable file
35d7bdc86031a2c David Hildenbrand 2021-04-23  1197   *
35d7bdc86031a2c David Hildenbrand 2021-04-23  1198   * This changes mm's executable file (shown as symlink /proc/[pid]/exe),
35d7bdc86031a2c David Hildenbrand 2021-04-23  1199   * dealing with concurrent invocation and without grabbing the mmap lock in
35d7bdc86031a2c David Hildenbrand 2021-04-23  1200   * write mode.
35d7bdc86031a2c David Hildenbrand 2021-04-23  1201   *
35d7bdc86031a2c David Hildenbrand 2021-04-23  1202   * Main user is sys_prctl(PR_SET_MM_MAP/EXE_FILE).
35d7bdc86031a2c David Hildenbrand 2021-04-23  1203   */
35d7bdc86031a2c David Hildenbrand 2021-04-23  1204  int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
35d7bdc86031a2c David Hildenbrand 2021-04-23  1205  {
35d7bdc86031a2c David Hildenbrand 2021-04-23  1206  	struct file *old_exe_file;
35d7bdc86031a2c David Hildenbrand 2021-04-23  1207  	int ret = 0;
35d7bdc86031a2c David Hildenbrand 2021-04-23  1208  
35d7bdc86031a2c David Hildenbrand 2021-04-23  1209  	/* set the new file, lockless */
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1210  	ret = deny_write_access(new_exe_file);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1211  	if (ret)
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1212  		return -EACCES;
35d7bdc86031a2c David Hildenbrand 2021-04-23  1213  	get_file(new_exe_file);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1214  
35d7bdc86031a2c David Hildenbrand 2021-04-23 @1215  	old_exe_file = xchg(&mm->exe_file, new_exe_file);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1216  	if (old_exe_file) {
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1217  		/*
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1218  		 * Don't race with dup_mmap() getting the file and disallowing
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1219  		 * write access while someone might open the file writable.
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1220  		 */
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1221  		mmap_read_lock(mm);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1222  		allow_write_access(old_exe_file);
35d7bdc86031a2c David Hildenbrand 2021-04-23  1223  		fput(old_exe_file);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1224  		mmap_read_unlock(mm);
fe69d560b5bd9ec David Hildenbrand 2021-04-23  1225  	}
35d7bdc86031a2c David Hildenbrand 2021-04-23  1226  	return 0;
35d7bdc86031a2c David Hildenbrand 2021-04-23  1227  }
3864601387cf419 Jiri Slaby        2011-05-26  1228  

---
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