linux-kernel - [PATCH 4.1 18/84] ipr: Fix incorrect trace indexing

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: <20150814174210.764845409@linuxfoundation.org>
Date:	Fri, 14 Aug 2015 10:41:46 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Wen Xiong <wenxiong@...ux.vnet.ibm.com>,
	Gabriel Krisman Bertazi <krisman@...ux.vnet.ibm.com>,
	Brian King <brking@...ux.vnet.ibm.com>,
	"Martin K. Petersen" <martin.petersen@...cle.com>,
	James Bottomley <JBottomley@...n.com>
Subject: [PATCH 4.1 18/84] ipr: Fix incorrect trace indexing

4.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Brian King <brking@...ux.vnet.ibm.com>

commit bb7c54339e6a10ecce5c4961adf5e75b3cf0af30 upstream.

When ipr's internal driver trace was changed to an atomic, a signed/unsigned
bug slipped in which results in us indexing backwards in our memory buffer
writing on memory that does not belong to us. This patch fixes this by removing
the modulo and instead just mask off the low bits.

Tested-by: Wen Xiong <wenxiong@...ux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@...ux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@...ux.vnet.ibm.com>
Signed-off-by: Brian King <brking@...ux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@...cle.com>
Signed-off-by: James Bottomley <JBottomley@...n.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/scsi/ipr.c |    5 +++--
 drivers/scsi/ipr.h |    1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -599,9 +599,10 @@ static void ipr_trc_hook(struct ipr_cmnd
 {
 	struct ipr_trace_entry *trace_entry;
 	struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+	unsigned int trace_index;
 
-	trace_entry = &ioa_cfg->trace[atomic_add_return
-			(1, &ioa_cfg->trace_index)%IPR_NUM_TRACE_ENTRIES];
+	trace_index = atomic_add_return(1, &ioa_cfg->trace_index) & IPR_TRACE_INDEX_MASK;
+	trace_entry = &ioa_cfg->trace[trace_index];
 	trace_entry->time = jiffies;
 	trace_entry->op_code = ipr_cmd->ioarcb.cmd_pkt.cdb[0];
 	trace_entry->type = type;
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -1486,6 +1486,7 @@ struct ipr_ioa_cfg {
 
 #define IPR_NUM_TRACE_INDEX_BITS	8
 #define IPR_NUM_TRACE_ENTRIES		(1 << IPR_NUM_TRACE_INDEX_BITS)
+#define IPR_TRACE_INDEX_MASK		(IPR_NUM_TRACE_ENTRIES - 1)
 #define IPR_TRACE_SIZE	(sizeof(struct ipr_trace_entry) * IPR_NUM_TRACE_ENTRIES)
 	char trace_start[8];
 #define IPR_TRACE_START_LABEL			"trace"


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/