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

commit 51520e03e70d6c73e33ee7cbe0319767d05764fe upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 6faeb2ab39601b561924aa6ec04ace126b963489..952ebd94e0ece13fa19be76ac924034c133e2ef1 100644 (file)
--- 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;