From b529ede2b07f26abe39f481a508480e8f40e3b9e Mon Sep 17 00:00:00 2001
From: David Disseldorp <ddiss@suse.de>
Date: Thu, 19 Oct 2017 01:39:19 +0200
Subject: [PATCH 1/2] target: fix PR state file path truncation
Git-commit: bdc79f0ed12ff55a9b56a91da04d0c8d8a786b9c
Patch-mainline: v4.15-rc1
References: bsc#1064606
If an LIO backstore is configured with a sufficiently long Unit Serial
string, alongside a similarly long dbroot path, then a truncated
Persistent Reservation APTPL state file path will be used. This
truncation can unintentionally lead to two LUs with differing serial
numbers sharing PR state file.
Fixes: fdddf932269a ("target: use new "dbroot" target attribute")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
drivers/target/target_core_pr.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -1974,24 +1974,21 @@ static int __core_scsi3_write_aptpl_to_f
struct t10_wwn *wwn = &dev->t10_wwn;
struct file *file;
int flags = O_RDWR | O_CREAT | O_TRUNC;
- char path[512];
+ char *path;
u32 pr_aptpl_buf_len;
int ret;
loff_t pos = 0;
- memset(path, 0, 512);
+ path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
+ &wwn->unit_serial[0]);
+ if (!path)
+ return -ENOMEM;
- if (strlen(&wwn->unit_serial[0]) >= 512) {
- pr_err("WWN value for struct se_device does not fit"
- " into path buffer\n");
- return -EMSGSIZE;
- }
-
- snprintf(path, 512, "%s/pr/aptpl_%s", db_root, &wwn->unit_serial[0]);
file = filp_open(path, flags, 0600);
if (IS_ERR(file)) {
pr_err("filp_open(%s) for APTPL metadata"
" failed\n", path);
+ kfree(path);
return PTR_ERR(file);
}
@@ -2001,6 +1998,7 @@ static int __core_scsi3_write_aptpl_to_f
if (ret < 0)
pr_debug("Error writing APTPL metadata file: %s\n", path);
fput(file);
+ kfree(path);
return (ret < 0) ? -EIO : 0;
}