Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Kunwu Chan <> | Subject | [PATCH v4 iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read | Date | Tue, 5 Dec 2023 17:58:44 +0800 |
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The size of "i40e_dbg_command_buf" is 256, the size of "name" depends on "IFNAMSIZ", plus a null character and format size, the total size is more than 256.
Improve readability and maintainability by replacing a hardcoded string allocation and formatting by the use of the kasprintf() helper.
Fixes: 02e9c290814c ("i40e: debugfs interface") Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Suggested-by: Simon Horman <horms@kernel.org> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> --- v2 - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf) v3 - Use kasprintf to improve readability and maintainability v4 - Fix memory leak in error path --- .../net/ethernet/intel/i40e/i40e_debugfs.c | 20 ++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c index 88240571721a..78a7200211b2 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c +++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c @@ -72,29 +72,31 @@ static ssize_t i40e_dbg_command_read(struct file *filp, char __user *buffer, { struct i40e_pf *pf = filp->private_data; int bytes_not_copied; - int buf_size = 256; char *buf; int len; /* don't allow partial reads */ if (*ppos != 0) return 0; - if (count < buf_size) - return -ENOSPC; - buf = kzalloc(buf_size, GFP_KERNEL); + buf = kasprintf(GFP_KERNEL, "%s: %s\n", + pf->vsi[pf->lan_vsi]->netdev->name, + i40e_dbg_command_buf); if (!buf) return -ENOSPC; - len = snprintf(buf, buf_size, "%s: %s\n", - pf->vsi[pf->lan_vsi]->netdev->name, - i40e_dbg_command_buf); + len = strlen(buf) + 1; + if (count < len) + bytes_not_copied = -ENOSPC; + else if (copy_to_user(buffer, buf, len)) + bytes_not_copied = -EFAULT; + else + bytes_not_copied = 0; - bytes_not_copied = copy_to_user(buffer, buf, len); kfree(buf); if (bytes_not_copied) - return -EFAULT; + return bytes_not_copied; *ppos = len; return len; -- 2.34.1
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