[PATCH v2 2/4] lib: update single-char callers of strtobool

Andy Shevchenko andy.shevchenko at gmail.com
Fri Feb 5 09:59:11 AEDT 2016


On Thu, Feb 4, 2016 at 11:00 PM, Kees Cook <keescook at chromium.org> wrote:
> Some callers of strtobool were passing a pointer to unterminated strings.
> In preparation of adding multi-character processing to kstrtobool, update
> the callers to not pass single-character pointers, and switch to using the
> new kstrtobool_from_user helper where possible.

Looks much better now!
My comment below.

>
> Signed-off-by: Kees Cook <keescook at chromium.org>
> Cc: Amitkumar Karwar <akarwar at marvell.com>
> Cc: Nishant Sarmukadam <nishants at marvell.com>
> Cc: Kalle Valo <kvalo at codeaurora.org>
> Cc: Steve French <sfrench at samba.org>
> Cc: linux-cifs at vger.kernel.org
> ---
>  drivers/net/wireless/marvell/mwifiex/debugfs.c | 10 ++---
>  fs/cifs/cifs_debug.c                           | 58 +++++++-------------------
>  fs/cifs/cifs_debug.h                           |  2 +-
>  fs/cifs/cifsfs.c                               |  6 +--
>  fs/cifs/cifsglob.h                             |  4 +-
>  5 files changed, 26 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/debugfs.c b/drivers/net/wireless/marvell/mwifiex/debugfs.c
> index 0b9c580af988..bd061b02bc04 100644
> --- a/drivers/net/wireless/marvell/mwifiex/debugfs.c
> +++ b/drivers/net/wireless/marvell/mwifiex/debugfs.c
> @@ -880,14 +880,12 @@ mwifiex_reset_write(struct file *file,
>  {
>         struct mwifiex_private *priv = file->private_data;
>         struct mwifiex_adapter *adapter = priv->adapter;
> -       char cmd;
>         bool result;
> +       int rc;
>
> -       if (copy_from_user(&cmd, ubuf, sizeof(cmd)))
> -               return -EFAULT;
> -
> -       if (strtobool(&cmd, &result))
> -               return -EINVAL;
> +       rc = kstrtobool_from_user(ubuf, count, 0, &result);
> +       if (rc)
> +               return rc;
>
>         if (!result)
>                 return -EINVAL;
> diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
> index 50b268483302..6ee59abcb69b 100644
> --- a/fs/cifs/cifs_debug.c
> +++ b/fs/cifs/cifs_debug.c
> @@ -255,7 +255,6 @@ static const struct file_operations cifs_debug_data_proc_fops = {
>  static ssize_t cifs_stats_proc_write(struct file *file,
>                 const char __user *buffer, size_t count, loff_t *ppos)
>  {
> -       char c;
>         bool bv;
>         int rc;
>         struct list_head *tmp1, *tmp2, *tmp3;
> @@ -263,11 +262,8 @@ static ssize_t cifs_stats_proc_write(struct file *file,
>         struct cifs_ses *ses;
>         struct cifs_tcon *tcon;
>
> -       rc = get_user(c, buffer);
> -       if (rc)
> -               return rc;
> -
> -       if (strtobool(&c, &bv) == 0) {
> +       rc = kstrtobool_from_user(buffer, count, 0, &bv);
> +       if (rc == 0) {
>  #ifdef CONFIG_CIFS_STATS2
>                 atomic_set(&totBufAllocCount, 0);
>                 atomic_set(&totSmBufAllocCount, 0);
> @@ -290,6 +286,8 @@ static ssize_t cifs_stats_proc_write(struct file *file,
>                         }
>                 }
>                 spin_unlock(&cifs_tcp_ses_lock);
> +       } else {
> +               return rc;
>         }
>
>         return count;
> @@ -433,17 +431,17 @@ static int cifsFYI_proc_open(struct inode *inode, struct file *file)
>  static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
>                 size_t count, loff_t *ppos)
>  {
> -       char c;
> +       char c[2] = { '\0' };
>         bool bv;
>         int rc;
>
> -       rc = get_user(c, buffer);
> +       rc = get_user(c[0], buffer);

>         if (rc)
>                 return rc;
> -       if (strtobool(&c, &bv) == 0)
> +       if (strtobool(c, &bv) == 0)
>                 cifsFYI = bv;
> -       else if ((c > '1') && (c <= '9'))
> -               cifsFYI = (int) (c - '0'); /* see cifs_debug.h for meanings */
> +       else if ((c[0] > '1') && (c[0] <= '9'))
> +               cifsFYI = (int) (c[0] - '0'); /* see cifs_debug.h for meanings */
>
>         return count;
>  }
> @@ -471,20 +469,12 @@ static int cifs_linux_ext_proc_open(struct inode *inode, struct file *file)
>  static ssize_t cifs_linux_ext_proc_write(struct file *file,
>                 const char __user *buffer, size_t count, loff_t *ppos)
>  {
> -       char c;
> -       bool bv;
>         int rc;
>
> -       rc = get_user(c, buffer);
> +       rc = kstrtobool_from_user(buffer, count, 0, &linuxExtEnabled);
>         if (rc)
>                 return rc;
>
> -       rc = strtobool(&c, &bv);
> -       if (rc)
> -               return rc;
> -
> -       linuxExtEnabled = bv;
> -
>         return count;
>  }
>
> @@ -511,20 +501,12 @@ static int cifs_lookup_cache_proc_open(struct inode *inode, struct file *file)
>  static ssize_t cifs_lookup_cache_proc_write(struct file *file,
>                 const char __user *buffer, size_t count, loff_t *ppos)
>  {
> -       char c;
> -       bool bv;
>         int rc;
>
> -       rc = get_user(c, buffer);
> +       rc = kstrtobool_from_user(buffer, count, 0, &lookupCacheEnabled);
>         if (rc)
>                 return rc;
>
> -       rc = strtobool(&c, &bv);
> -       if (rc)
> -               return rc;
> -
> -       lookupCacheEnabled = bv;
> -
>         return count;
>  }
>
> @@ -551,20 +533,12 @@ static int traceSMB_proc_open(struct inode *inode, struct file *file)
>  static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
>                 size_t count, loff_t *ppos)
>  {
> -       char c;
> -       bool bv;
>         int rc;
>
> -       rc = get_user(c, buffer);
> +       rc = kstrtobool_from_user(buffer, count, 0, &traceSMB);
>         if (rc)
>                 return rc;
>
> -       rc = strtobool(&c, &bv);
> -       if (rc)
> -               return rc;
> -
> -       traceSMB = bv;
> -
>         return count;
>  }
>
> @@ -622,7 +596,7 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
>         int rc;
>         unsigned int flags;
>         char flags_string[12];
> -       char c;
> +       char c[2] = { '\0' };

Can we use flag_string directly here?

>         bool bv;
>
>         if ((count < 1) || (count > 11))
> @@ -635,11 +609,11 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
>
>         if (count < 3) {
>                 /* single char or single char followed by null */
> -               c = flags_string[0];
> -               if (strtobool(&c, &bv) == 0) {
> +               c[0] = flags_string[0];

> +               if (strtobool(c, &bv) == 0) {


>                         global_secflags = bv ? CIFSSEC_MAX : CIFSSEC_DEF;
>                         return count;
> -               } else if (!isdigit(c)) {
> +               } else if (!isdigit(c[0])) {
>                         cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
>                                         flags_string);
>                         return -EINVAL;
> diff --git a/fs/cifs/cifs_debug.h b/fs/cifs/cifs_debug.h
> index 66cf0f9fff89..c611ca2339d7 100644
> --- a/fs/cifs/cifs_debug.h
> +++ b/fs/cifs/cifs_debug.h
> @@ -25,7 +25,7 @@
>  void cifs_dump_mem(char *label, void *data, int length);
>  void cifs_dump_detail(void *);
>  void cifs_dump_mids(struct TCP_Server_Info *);
> -extern int traceSMB;           /* flag which enables the function below */
> +extern bool traceSMB;          /* flag which enables the function below */
>  void dump_smb(void *, int);
>  #define CIFS_INFO      0x01
>  #define CIFS_RC                0x02
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index c48ca13673e3..931b446f2a44 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -54,10 +54,10 @@
>  #endif
>
>  int cifsFYI = 0;
> -int traceSMB = 0;
> +bool traceSMB;
>  bool enable_oplocks = true;
> -unsigned int linuxExtEnabled = 1;
> -unsigned int lookupCacheEnabled = 1;
> +bool linuxExtEnabled = true;
> +bool lookupCacheEnabled = true;
>  unsigned int global_secflags = CIFSSEC_DEF;
>  /* unsigned int ntlmv2_support = 0; */
>  unsigned int sign_CIFS_PDUs = 1;
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index a25b2513f146..d21da9f05bae 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -1596,11 +1596,11 @@ GLOBAL_EXTERN atomic_t midCount;
>
>  /* Misc globals */
>  GLOBAL_EXTERN bool enable_oplocks; /* enable or disable oplocks */
> -GLOBAL_EXTERN unsigned int lookupCacheEnabled;
> +GLOBAL_EXTERN bool lookupCacheEnabled;
>  GLOBAL_EXTERN unsigned int global_secflags;    /* if on, session setup sent
>                                 with more secure ntlmssp2 challenge/resp */
>  GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
> -GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
> +GLOBAL_EXTERN bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
>  GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
>  GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
>  GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
> --
> 2.6.3
>



-- 
With Best Regards,
Andy Shevchenko


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