From: "Borislav Petkov (AMD)" <bp@alien8.de> stable inclusion from stable-v6.6.135 commit d3de72e2a2b9ee3a57734c1c068823e41a707715 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14436 CVE: CVE-2026-31689 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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> Signed-off-by: Ye Bin <yebin10@huawei.com> --- drivers/edac/edac_mc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 6faeb2ab3960..952ebd94e0ec 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; -- 2.34.1