From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C749731E824; Sat, 12 Sep 2026 13:46:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789220805; cv=none; b=tqOF05rTc8oFPSXlXbGRPT5kV87yBK0lvZ5VqXCx8aHnfXD3WnihmxYTdC+ceSgtJingygdYeSfBPLT6oyz9fk/kRi5dJPc65GrFfK7aws5E7yEm9u+egwjlDoa0tMSlY718+U4Ql4SW0Vin/CDy8smKb3XUrdruMW2Pq0LzR+o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789220805; c=relaxed/simple; bh=Mmo4wF8/q13QyI7v153tAJptu+3teI7kZVB7YbI8wLA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QvGgNf2lSgMhSa05v3yqJ3iKVJUuTRSIDVH+jCpRvkO28PWWkA1QHyv+MXJ09qWX/ClnfsDYnDJya3LwJDwuuK5pYu2HoOhAPBoWoqVeWCFz8tpIonHzW5hpAbtUx26VBb71jo916DbkVZaouxqgbaYOc2Uk4XOlELsy034Tp5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2pqyCItU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="2pqyCItU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D1051F000FF; Sat, 12 Sep 2026 13:46:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789220801; bh=nTTk6HcDuZUS9chUXMjlQDzj3Bi77FrScW1RrPXFhiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2pqyCItU8LW8biSPmKtr4W0AscJCjQncgbcOCsXVN/+Jl8Jep7ejO3xHDxrnp64Dr lX8UgL1rRk36RijDvAYwigC2CV4sJcQnAGL69enhs/aMDymRP9trtM6/9F0p2e3ykq Nzuxee4fX2r1mqmnAKbdpaMMerSHfBwboo8pSRGU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuan-Wei Chiu , Georgi Djakov Subject: [PATCH 6.6 0250/1424] interconnect: Fix use after free in icc_get() and of_icc_get_by_index() Date: Sat, 12 Sep 2026 08:44:42 +0200 Message-ID: <20260912065612.877123100@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kuan-Wei Chiu commit 25c7e242aca084fdc1098248194032317dca625d upstream. In of_icc_get_by_index() and icc_get(), if the dynamic allocation for path->name fails via kasprintf(), the error handling path directly calls kfree(path) to free the path object and returns an error. However, prior to this point, path_find() calls path_init(), which already links the path's requests into the req_list of the respective interconnect nodes via hlist_add_head(). Directly invoking kfree(path) leaves dangling pointers in the hlist. A subsequent call to icc_get() or icc_set_bw() will traverse or modify these corrupted lists, triggering a slab use afterfree. KASAN report showing the vulnerability when reproducing via debugfs: BUG: KASAN: slab-use-after-free in path_find+0x6f8/0xcfc Write of size 8 at addr fff000000d43f748 by task sh/1 ... Call trace: kasan_report+0xac/0xfc path_find+0x6f8/0xcfc icc_get+0x148/0x380 icc_get_set+0xf8/0x2d0 ... Freed by task 1: kfree+0x1a0/0x4a4 icc_get+0x2cc/0x380 icc_get_set+0xf8/0x2d0 Fix this by replacing kfree(path) with the proper teardown function, icc_put(path), which safely removes the requests from the req_list using hlist_del() and drops the provider usage references before freeing the memory. Additionally, in icc_get(), ensure that the icc_lock mutex is released prior to calling icc_put(path) to avoid a deadlock, as icc_put() internally acquires the same lock. Fixes: 3791163602f7 ("interconnect: Handle memory allocation errors") Cc: stable@vger.kernel.org Signed-off-by: Kuan-Wei Chiu Link: https://patch.msgid.link/20260416190840.1753468-1-visitorckw@gmail.com Signed-off-by: Georgi Djakov Signed-off-by: Greg Kroah-Hartman --- drivers/interconnect/core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -526,7 +526,7 @@ struct icc_path *of_icc_get_by_index(str path->name = kasprintf(GFP_KERNEL, "%s-%s", src_data->node->name, dst_data->node->name); if (!path->name) { - kfree(path); + icc_put(path); path = ERR_PTR(-ENOMEM); } @@ -624,8 +624,9 @@ struct icc_path *icc_get(struct device * path->name = kasprintf(GFP_KERNEL, "%s-%s", src_node->name, dst_node->name); if (!path->name) { - kfree(path); - path = ERR_PTR(-ENOMEM); + mutex_unlock(&icc_lock); + icc_put(path); + return ERR_PTR(-ENOMEM); } out: mutex_unlock(&icc_lock);