From: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
To: ptsm@linux.microsoft.com, nipun.gupta@amd.com,
nikhil.agarwal@amd.com, abhijit.gangurde@amd.com,
puneet.gupta@amd.com, gregkh@linuxfoundation.org,
linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Subject: [PATCH 2/2] cdx: Fix double free when sysfs file creation fails
Date: Fri, 20 Mar 2026 03:21:17 -0700 [thread overview]
Message-ID: <20260320102117.1554548-1-ptsm@linux.microsoft.com> (raw)
In-Reply-To: <20260320101933.1554416-1-ptsm@linux.microsoft.com>
In cdx_create_res_attr(), if sysfs_create_bin_file() fails, the code
frees res_attr but doesn't set cdx_dev->res_attr[num] to NULL. This
leaves a dangling pointer in the array. Then cdx_destroy_res_attr()
frees the already-freed memory. Fix the double free by initializing
cdx_dev->res_attr[num] after sysfs_create_bin_file() completes.
Fixes: aeda33ab8160 ("cdx: create sysfs bin files for cdx resources")
Cc: stable@vger.kernel.org
Signed-off-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
---
drivers/cdx/cdx.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index 9196dc50a48d..a4e03fb07c4c 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -768,7 +768,6 @@ static int cdx_create_res_attr(struct cdx_device *cdx_dev, int num)
sysfs_bin_attr_init(res_attr);
- cdx_dev->res_attr[num] = res_attr;
sprintf(res_attr_name, "resource%d", num);
res_attr->mmap = cdx_mmap_resource;
@@ -777,8 +776,12 @@ static int cdx_create_res_attr(struct cdx_device *cdx_dev, int num)
res_attr->size = cdx_resource_len(cdx_dev, num);
res_attr->private = (void *)(unsigned long)num;
ret = sysfs_create_bin_file(&cdx_dev->dev.kobj, res_attr);
- if (ret)
+ if (ret) {
kfree(res_attr);
+ return ret;
+ }
+
+ cdx_dev->res_attr[num] = res_attr;
return ret;
}
--
2.49.0
prev parent reply other threads:[~2026-03-20 10:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 10:19 [PATCH 1/2] vfio/cdx: Fix NULL pointer dereference in interrupt trigger path Prasanna Kumar T S M
2026-03-20 10:21 ` Prasanna Kumar T S M [this message]
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