From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCHv4 5/5] scsi_devinfo: fixup string compare Date: Tue, 29 Aug 2017 10:49:24 +0200 Message-ID: <1503996564-110464-6-git-send-email-hare@suse.de> References: <1503996564-110464-1-git-send-email-hare@suse.de> Return-path: Received: from mx2.suse.de ([195.135.220.15]:46796 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751770AbdH2Itg (ORCPT ); Tue, 29 Aug 2017 04:49:36 -0400 In-Reply-To: <1503996564-110464-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Christoph Hellwig , James Bottomley , Alan@suse.de, "Stern , Hannes Reinecke When checking the model and vendor string we need to use the minimum value of either string, otherwise we'll miss out on wildcard matches. And we should take card when matching with zero size strings; results might be unpredictable. With this patch the rules for matching devinfo strings are as follows: - Vendor strings must match exactly - Empty Model strings will only match if the devinfo model is also empty - Model strings shorter than the devinfo model string will not match Fixes: 5e7ff2c ("SCSI: fix new bug in scsi_dev_info_list string matching") Signed-off-by: Hannes Reinecke Reviewed-by: Alan Stern --- drivers/scsi/scsi_devinfo.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c index 6858ad8..d39b27c 100644 --- a/drivers/scsi/scsi_devinfo.c +++ b/drivers/scsi/scsi_devinfo.c @@ -399,8 +399,8 @@ int scsi_dev_info_list_add_keyed(int compatible, char *vendor, char *model, /** * scsi_dev_info_list_find - find a matching dev_info list entry. - * @vendor: vendor string - * @model: model (product) string + * @vendor: full vendor string + * @model: full model (product) string * @key: specify list to use * * Description: @@ -415,7 +415,7 @@ static struct scsi_dev_info_list *scsi_dev_info_list_find(const char *vendor, struct scsi_dev_info_list *devinfo; struct scsi_dev_info_list_table *devinfo_table = scsi_devinfo_lookup_by_key(key); - size_t vmax, mmax; + size_t vmax, mmax, mlen; const char *vskip, *mskip; if (IS_ERR(devinfo_table)) @@ -454,15 +454,18 @@ static struct scsi_dev_info_list *scsi_dev_info_list_find(const char *vendor, dev_info_list) { if (devinfo->compatible) { /* - * Behave like the older version of get_device_flags. + * vendor strings must be an exact match */ - if (memcmp(devinfo->vendor, vskip, vmax) || - (vmax < sizeof(devinfo->vendor) && - devinfo->vendor[vmax])) + if (vmax != strlen(devinfo->vendor) || + memcmp(devinfo->vendor, vskip, vmax)) continue; - if (memcmp(devinfo->model, mskip, mmax) || - (mmax < sizeof(devinfo->model) && - devinfo->model[mmax])) + + /* + * @model specifies the full string, and + * must be larger or equal to devinfo->model + */ + mlen = strlen(devinfo->model); + if (mmax < mlen || memcmp(devinfo->model, mskip, mlen)) continue; return devinfo; } else { -- 1.8.5.6