From: Borislav Petkov (AMD) <bp@alien8.de>
Date: Tue, 31 Mar 2026 12:16:23 +0000 (+0200)
Subject: EDAC/mc: Fix error path ordering in edac_mc_alloc()
X-Git-Tag: v7.0~1^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51520e03e70d6c73e33ee7cbe0319767d05764fe;p=thirdparty%2Fkernel%2Fstable.git

EDAC/mc: Fix error path ordering in edac_mc_alloc()

When the mci->pvt_info allocation in edac_mc_alloc() fails, the error path
will call put_device() which will end up calling the device's release
function.

However, the init ordering is wrong such that device_initialize() happens
*after* the failed allocation and thus the device itself and the release
function pointer are not initialized yet when they're called:

  MCE: In-kernel MCE decoding enabled.
  ------------[ cut here ]------------
  kobject: '(null)': is not initialized, yet kobject_put() is being called.
  WARNING: lib/kobject.c:734 at kobject_put, CPU#22: systemd-udevd
  CPU: 22 UID: 0 PID: 538 Comm: systemd-udevd Not tainted 7.0.0-rc1+ #2 PREEMPT(full)
  RIP: 0010:kobject_put
  Call Trace:
   <TASK>
   edac_mc_alloc+0xbe/0xe0 [edac_core]
   amd64_edac_init+0x7a4/0xff0 [amd64_edac]
   ? __pfx_amd64_edac_init+0x10/0x10 [amd64_edac]
   do_one_initcall
   ...

Reorder the calling sequence so that the device is initialized and thus the
release function pointer is properly set before it can be used.

This was found by Claude while reviewing another EDAC patch.

Fixes: 0bbb265f7089 ("EDAC/mc: Get rid of silly one-shot struct allocation in edac_mc_alloc()")
Reported-by: Claude Code:claude-opus-4.5
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: stable@kernel.org
Link: https://patch.msgid.link/20260331121623.4871-1-bp@kernel.org
---

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 29e9828422bb0..11d66333d93b4 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -369,13 +369,13 @@ struct mem_ctl_info *edac_mc_alloc(unsigned int mc_num,
 	if (!mci->layers)
 		goto error;
 
+	mci->dev.release = mci_release;
+	device_initialize(&mci->dev);
+
 	mci->pvt_info = kzalloc(sz_pvt, GFP_KERNEL);
 	if (!mci->pvt_info)
 		goto error;
 
-	mci->dev.release = mci_release;
-	device_initialize(&mci->dev);
-
 	/* setup index and various internal pointers */
 	mci->mc_idx = mc_num;
 	mci->tot_dimms = tot_dimms;