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Date:   Fri, 19 Aug 2022 12:25:10 -0400
From:   Richard Guy Briggs <rgb@redhat.com>
To:     kernel test robot <lkp@intel.com>
Cc:     Linux-Audit Mailing List <linux-audit@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org, llvm@lists.linux.dev,
        kbuild-all@lists.01.org, Paul Moore <paul@paul-moore.com>,
        Eric Paris <eparis@parisplace.org>,
        Steve Grubb <sgrubb@redhat.com>, Jan Kara <jack@suse.cz>,
        Amir Goldstein <amir73il@gmail.com>
Subject: Re: [PATCH v4 2/4] fanotify: define struct members to hold response
 decision context
Message-ID: <Yv+5ZkFxhR+JK/Rj@madcap2.tricolour.ca>
References: <8767f3a0d43d6a994584b86c03eb659a662cc416.1659996830.git.rgb@redhat.com>
 <202208102231.qSUdYAdb-lkp@intel.com>
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In-Reply-To: <202208102231.qSUdYAdb-lkp@intel.com>
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On 2022-08-10 22:28, kernel test robot wrote:
> Hi Richard,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on jack-fs/fsnotify]
> [also build test WARNING on pcmoore-audit/next linus/master v5.19 next-20220810]
> [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#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Richard-Guy-Briggs/fanotify-Allow-user-space-to-pass-back-additional-audit-info/20220810-012825
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git fsnotify
> config: i386-randconfig-a013 (https://download.01.org/0day-ci/archive/20220810/202208102231.qSUdYAdb-lkp@intel.com/config)
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 5f1c7e2cc5a3c07cbc2412e851a7283c1841f520)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # https://github.com/intel-lab-lkp/linux/commit/a943676abc023c094f05b45f4d61936c567507a2
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Richard-Guy-Briggs/fanotify-Allow-user-space-to-pass-back-additional-audit-info/20220810-012825
>         git checkout a943676abc023c094f05b45f4d61936c567507a2
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/notify/fanotify/
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> fs/notify/fanotify/fanotify_user.c:325:35: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]

Interesting.  When I "fix" it, my compiler complains:

	fs/notify/fanotify/fanotify_user.c:324:11: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 8 has type ‘size_t’ {aka ‘long unsigned int’} [-Wformat=]

>                     group, fd, response, info_buf, count);
>                                                    ^~~~~
>    include/linux/printk.h:594:38: note: expanded from macro 'pr_debug'
>            no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
>                                        ~~~     ^~~~~~~~~~~
>    include/linux/printk.h:131:17: note: expanded from macro 'no_printk'
>                    printk(fmt, ##__VA_ARGS__);             \
>                           ~~~    ^~~~~~~~~~~
>    include/linux/printk.h:464:60: note: expanded from macro 'printk'
>    #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
>                                                        ~~~    ^~~~~~~~~~~
>    include/linux/printk.h:436:19: note: expanded from macro 'printk_index_wrap'
>                    _p_func(_fmt, ##__VA_ARGS__);                           \
>                            ~~~~    ^~~~~~~~~~~
>    1 warning generated.
> 
> 
> vim +325 fs/notify/fanotify/fanotify_user.c
> 
>    312	
>    313	static int process_access_response(struct fsnotify_group *group,
>    314					   struct fanotify_response *response_struct,
>    315					   const char __user *buf,
>    316					   size_t count)
>    317	{
>    318		struct fanotify_perm_event *event;
>    319		int fd = response_struct->fd;
>    320		u32 response = response_struct->response;
>    321		struct fanotify_response_info_header info_hdr;
>    322		char *info_buf = NULL;
>    323	
>    324		pr_debug("%s: group=%p fd=%d response=%u buf=%p size=%lu\n", __func__,
>  > 325			 group, fd, response, info_buf, count);
>    326		/*
>    327		 * make sure the response is valid, if invalid we do nothing and either
>    328		 * userspace can send a valid response or we will clean it up after the
>    329		 * timeout
>    330		 */
>    331		if (response & ~FANOTIFY_RESPONSE_VALID_MASK)
>    332			return -EINVAL;
>    333		switch (response & FANOTIFY_RESPONSE_ACCESS) {
>    334		case FAN_ALLOW:
>    335		case FAN_DENY:
>    336			break;
>    337		default:
>    338			return -EINVAL;
>    339		}
>    340		if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT))
>    341			return -EINVAL;
>    342		if (fd < 0)
>    343			return -EINVAL;
>    344		if (response & FAN_INFO) {
>    345			size_t c = count;
>    346			const char __user *ib = buf;
>    347	
>    348			if (c <= 0)
>    349				return -EINVAL;
>    350			while (c >= sizeof(info_hdr)) {
>    351				if (copy_from_user(&info_hdr, ib, sizeof(info_hdr)))
>    352					return -EFAULT;
>    353				if (info_hdr.pad != 0)
>    354					return -EINVAL;
>    355				if (c < info_hdr.len)
>    356					return -EINVAL;
>    357				switch (info_hdr.type) {
>    358				case FAN_RESPONSE_INFO_AUDIT_RULE:
>    359					break;
>    360				case FAN_RESPONSE_INFO_NONE:
>    361				default:
>    362					return -EINVAL;
>    363				}
>    364				c -= info_hdr.len;
>    365				ib += info_hdr.len;
>    366			}
>    367			if (c != 0)
>    368				return -EINVAL;
>    369			/* Simplistic check for now */
>    370			if (count != sizeof(struct fanotify_response_info_audit_rule))
>    371				return -EINVAL;
>    372			info_buf = kmalloc(sizeof(struct fanotify_response_info_audit_rule),
>    373					   GFP_KERNEL);
>    374			if (!info_buf)
>    375				return -ENOMEM;
>    376			if (copy_from_user(info_buf, buf, count))
>    377				return -EFAULT;
>    378		}
>    379		spin_lock(&group->notification_lock);
>    380		list_for_each_entry(event, &group->fanotify_data.access_list,
>    381				    fae.fse.list) {
>    382			if (event->fd != fd)
>    383				continue;
>    384	
>    385			list_del_init(&event->fae.fse.list);
>    386			/* finish_permission_event() eats info_buf */
>    387			finish_permission_event(group, event, response_struct,
>    388						count, info_buf);
>    389			wake_up(&group->fanotify_data.access_waitq);
>    390			return 0;
>    391		}
>    392		spin_unlock(&group->notification_lock);
>    393	
>    394		return -ENOENT;
>    395	}
>    396	
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
> 

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635