This is a note to let you know that I've just added the patch titled cxl/acpi: Fix a use-after-free in cxl_parse_cfmws() to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cxl-acpi-fix-a-use-after-free-in-cxl_parse_cfmws.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dc3135d39f72f727f6469b5124b63f9af596d76f Author: Breno Leitao <leitao@xxxxxxxxxx> Date: Fri Jul 14 02:31:45 2023 -0700 cxl/acpi: Fix a use-after-free in cxl_parse_cfmws() [ Upstream commit 4cf67d3cc9994a59cf77bb9c0ccf9007fe916afe ] KASAN and KFENCE detected an user-after-free in the CXL driver. This happens in the cxl_decoder_add() fail path. KASAN prints the following error: BUG: KASAN: slab-use-after-free in cxl_parse_cfmws (drivers/cxl/acpi.c:299) This happens in cxl_parse_cfmws(), where put_device() is called, releasing cxld, which is accessed later. Use the local variables in the dev_err() instead of pointing to the released memory. Since the dev_err() is printing a resource, change the open coded print format to use the %pr format specifier. Fixes: e50fe01e1f2a ("cxl/core: Drop ->platform_res attribute for root decoders") Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230714093146.2253438-1-leitao@xxxxxxxxxx Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index fb649683dd3ac..55907a94cb388 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -154,8 +154,7 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, else rc = cxl_decoder_autoremove(dev, cxld); if (rc) { - dev_err(dev, "Failed to add decode range [%#llx - %#llx]\n", - cxld->hpa_range.start, cxld->hpa_range.end); + dev_err(dev, "Failed to add decode range: %pr", res); return 0; } dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n",