linux-kernel - Re: [PATCH] misc: misc_minor_alloc to allocate ids for all dynamic/misc dynamic minors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f38e017e-40ef-4241-8701-fc56c5c2d06d@stanley.mountain>
Date: Wed, 16 Oct 2024 17:22:45 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: oe-kbuild@...ts.linux.dev, Vimal Agrawal <avimalin@...il.com>,
	linux-kernel@...r.kernel.org, gregkh@...uxfoundation.org,
	arnd@...db.de
Cc: lkp@...el.com, oe-kbuild-all@...ts.linux.dev, avimalin@...il.com,
	vimal.agrawal@...hos.com
Subject: Re: [PATCH] misc: misc_minor_alloc to allocate ids for all
 dynamic/misc dynamic minors

Hi Vimal,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vimal-Agrawal/misc-misc_minor_alloc-to-allocate-ids-for-all-dynamic-misc-dynamic-minors/20241014-211915
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/20241014131416.27324-1-vimal.agrawal%40sophos.com
patch subject: [PATCH] misc: misc_minor_alloc to allocate ids for all dynamic/misc dynamic minors
config: sparc64-randconfig-r072-20241015 (https://download.01.org/0day-ci/archive/20241016/202410161811.aIPEJHOt-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 14.1.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@...el.com>
| Reported-by: Dan Carpenter <dan.carpenter@...aro.org>
| Closes: https://lore.kernel.org/r/202410161811.aIPEJHOt-lkp@intel.com/

smatch warnings:
drivers/char/misc.c:89 misc_minor_alloc() error: uninitialized symbol 'ret'.

vim +/ret +89 drivers/char/misc.c

d52c84545e305b Vimal Agrawal    2024-10-14  66  static int misc_minor_alloc(int minor)
ab760791c0cfbb D Scott Phillips 2022-11-14  67  {
ab760791c0cfbb D Scott Phillips 2022-11-14  68  	int ret;
ab760791c0cfbb D Scott Phillips 2022-11-14  69  
d52c84545e305b Vimal Agrawal    2024-10-14  70  	if (minor == MISC_DYNAMIC_MINOR) {
d52c84545e305b Vimal Agrawal    2024-10-14  71  		/* allocate free id */
ab760791c0cfbb D Scott Phillips 2022-11-14  72  		ret = ida_alloc_max(&misc_minors_ida, DYNAMIC_MINORS - 1, GFP_KERNEL);
ab760791c0cfbb D Scott Phillips 2022-11-14  73  		if (ret >= 0) {
ab760791c0cfbb D Scott Phillips 2022-11-14  74  			ret = DYNAMIC_MINORS - ret - 1;
ab760791c0cfbb D Scott Phillips 2022-11-14  75  		} else {
ab760791c0cfbb D Scott Phillips 2022-11-14  76  			ret = ida_alloc_range(&misc_minors_ida, MISC_DYNAMIC_MINOR + 1,
ab760791c0cfbb D Scott Phillips 2022-11-14  77  				      MINORMASK, GFP_KERNEL);
ab760791c0cfbb D Scott Phillips 2022-11-14  78  		}
d52c84545e305b Vimal Agrawal    2024-10-14  79  	} else {
d52c84545e305b Vimal Agrawal    2024-10-14  80  		/* specific minor, check if it is in dynamic or misc dynamic range  */
d52c84545e305b Vimal Agrawal    2024-10-14  81  		if (minor < DYNAMIC_MINORS) {
d52c84545e305b Vimal Agrawal    2024-10-14  82  			minor = DYNAMIC_MINORS - minor - 1;
d52c84545e305b Vimal Agrawal    2024-10-14  83  			ret = ida_alloc_range(&misc_minors_ida, minor, minor, GFP_KERNEL);
d52c84545e305b Vimal Agrawal    2024-10-14  84  		}
d52c84545e305b Vimal Agrawal    2024-10-14  85  
d52c84545e305b Vimal Agrawal    2024-10-14  86  		if (minor > MISC_DYNAMIC_MINOR)
d52c84545e305b Vimal Agrawal    2024-10-14  87  			ret = ida_alloc_range(&misc_minors_ida, minor, minor, GFP_KERNEL);

What about if minor is >= DYNAMIC_MINORS (128) but <= MISC_DYNAMIC_MINOR (255)?

d52c84545e305b Vimal Agrawal    2024-10-14  88  	}
ab760791c0cfbb D Scott Phillips 2022-11-14 @89  	return ret;
ab760791c0cfbb D Scott Phillips 2022-11-14  90  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki