mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: kernel test robot <lkp@intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kbuild-all@lists.01.org, devel@driverdev.osuosl.org,
	linux-kernel@vger.kernel.org
Subject: [driver-core:debugfs_cleanup 1/2] fs/d_path.c:59 prepend() warn: unsigned 'p->len' is never less than zero.
Date: Thu, 30 Sep 2021 12:17:32 +0800	[thread overview]
Message-ID: <202109301219.cZqUlzDk-lkp@intel.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 2517 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git debugfs_cleanup
head:   c4535d1b074f3fdd9476e83526d4e9b53f41a7b5
commit: 473082c5bbad92c5909ccf75fb28df699b94de82 [1/2] fs: make d_path-like functions all have unsigned size
config: i386-randconfig-m021-20210929 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

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

smatch warnings:
fs/d_path.c:59 prepend() warn: unsigned 'p->len' is never less than zero.

vim +59 fs/d_path.c

b0cfcdd9b9672ea Linus Torvalds 2021-07-16  55  
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  56  static bool prepend(struct prepend_buffer *p, const char *str, int namelen)
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  57  {
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  58  	// Already overflowed?
b0cfcdd9b9672ea Linus Torvalds 2021-07-16 @59  	if (p->len < 0)
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  60  		return false;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  61  
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  62  	// Will overflow?
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  63  	if (p->len < namelen) {
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  64  		// Fill as much as possible from the end of the name
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  65  		str += namelen - p->len;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  66  		p->buf -= p->len;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  67  		prepend_copy(p->buf, str, p->len);
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  68  		p->len = -1;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  69  		return false;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  70  	}
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  71  
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  72  	// Fits fully
ad08ae586586ea9 Al Viro        2021-05-12  73  	p->len -= namelen;
ad08ae586586ea9 Al Viro        2021-05-12  74  	p->buf -= namelen;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  75  	return prepend_copy(p->buf, str, namelen);
7a5cf791a747640 Al Viro        2018-03-05  76  }
7a5cf791a747640 Al Viro        2018-03-05  77  

:::::: The code at line 59 was first introduced by commit
:::::: b0cfcdd9b9672ea90642f33d6c0dd8516553adf2 d_path: make 'prepend()' fill up the buffer exactly on overflow

:::::: TO: Linus Torvalds <torvalds@linux-foundation.org>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 35352 bytes --]

WARNING: multiple messages have this Message-ID

From: Dan Carpenter <dan.carpenter@oracle.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org, kbuild-all@lists.01.org,
	linux-kernel@vger.kernel.org
Subject: [driver-core:debugfs_cleanup 1/2] fs/d_path.c:59 prepend() warn: unsigned 'p->len' is never less than zero.
Date: Thu, 30 Sep 2021 12:46:59 +0300	[thread overview]
Message-ID: <202109301219.cZqUlzDk-lkp@intel.com> (raw)
Message-ID: <20210930094659.H5ZE5JeQWARjCN4fNhDEuGQKefueHD0M2_53IcDJ2g4@z> (raw)

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git debugfs_cleanup
head:   c4535d1b074f3fdd9476e83526d4e9b53f41a7b5
commit: 473082c5bbad92c5909ccf75fb28df699b94de82 [1/2] fs: make d_path-like functions all have unsigned size
config: i386-randconfig-m021-20210929 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

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

smatch warnings:
fs/d_path.c:59 prepend() warn: unsigned 'p->len' is never less than zero.

vim +59 fs/d_path.c

b0cfcdd9b9672ea Linus Torvalds 2021-07-16  56  static bool prepend(struct prepend_buffer *p, const char *str, int namelen)
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  57  {
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  58  	// Already overflowed?
b0cfcdd9b9672ea Linus Torvalds 2021-07-16 @59  	if (p->len < 0)

This is impossible now.

b0cfcdd9b9672ea Linus Torvalds 2021-07-16  60  		return false;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  61  
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  62  	// Will overflow?
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  63  	if (p->len < namelen) {
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  64  		// Fill as much as possible from the end of the name
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  65  		str += namelen - p->len;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  66  		p->buf -= p->len;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  67  		prepend_copy(p->buf, str, p->len);
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  68  		p->len = -1;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  69  		return false;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  70  	}
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  71  
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  72  	// Fits fully
ad08ae586586ea9 Al Viro        2021-05-12  73  	p->len -= namelen;
ad08ae586586ea9 Al Viro        2021-05-12  74  	p->buf -= namelen;
b0cfcdd9b9672ea Linus Torvalds 2021-07-16  75  	return prepend_copy(p->buf, str, namelen);
7a5cf791a747640 Al Viro        2018-03-05  76  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel


             reply	other threads:[~2021-09-30  4:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-30  4:17 kernel test robot [this message]
2021-09-30  9:46 ` Dan Carpenter

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=202109301219.cZqUlzDk-lkp@intel.com \
    --to=lkp@intel.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=kbuild-all@lists.01.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®