From patchwork Fri Jan 10 06:16:38 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Ridong X-Patchwork-Id: 856316 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 DEB2B17B500; Fri, 10 Jan 2025 06:27:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736490442; cv=none; b=QmCvi/oUCeOvcDsssYHeCOMkqj6iWD5n0z9+1B2IewNanwX18A/Jz7kTw0nNUhIpqbY2U7E6oEVD/DUWdzFIuJv4G4A1hKFeHMwd7WScuin3pJCj+NRu2UreOZTJqez9tHD5I5hFAb6fgj0nsDnoSDsB7hliIT8e3Nt8+3YRABs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736490442; c=relaxed/simple; bh=KDzoksDjv09O6cM7IUv0CrR1OWRVol+v6IzaT2A8I8k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ibvtvmO5n9DvOwns4EVuPMYx473Z9KxSRd55DbbmoBvF0rEDiMAZr1kcerOnDxghSrnXbdsLI92McCgc+nFY6dBZM8LUwQ2TMaI8Bg2dSoRaV7kesHE6q/4C+3mjJkvvJ/sWnwRLnAfaAHSp0wmCgTGtmPjq2NEiQoSFNvT1s28= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4YTsBP6mr8z4f3jJL; Fri, 10 Jan 2025 14:26:53 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.75]) by mail.maildlp.com (Postfix) with ESMTP id 2ED491A0B21; Fri, 10 Jan 2025 14:27:14 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP2 (Coremail) with SMTP id Syh0CgCXoGOzvYBnLbQtAg--.33415S4; Fri, 10 Jan 2025 14:27:12 +0800 (CST) From: Chen Ridong To: steffen.klassert@secunet.com, daniel.m.jordan@oracle.com, herbert@gondor.apana.org.au, nstange@suse.de Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, chenridong@huawei.com, wangweiyang2@huawei.com Subject: [PATCH v2 2/3] padata: fix UAF in padata_reorder Date: Fri, 10 Jan 2025 06:16:38 +0000 Message-Id: <20250110061639.1280907-3-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250110061639.1280907-1-chenridong@huaweicloud.com> References: <20250110061639.1280907-1-chenridong@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: Syh0CgCXoGOzvYBnLbQtAg--.33415S4 X-Coremail-Antispam: 1UD129KBjvJXoWxXr47WFWkXw47JrWrCFWkCrg_yoW5GF43pF ZxCrW7KrW8Gr1xGw43Ja1xW34ruw4Uury3KFWrKF1furW3Jr1vvrn2y3yFgryYvr9ay34D Za1DXFy7KwsrAFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPIb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwCY1x0262kKe7AKxVWUAVWUtwCF04k20xvY0x0EwIxGrw CF54CYxVCY1x0262kKe7AKxVWUAVWUtwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02 F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GF ylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jY LvtUUUUU= X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ From: Chen Ridong A bug was found when run ltp test: BUG: KASAN: slab-use-after-free in padata_find_next+0x29/0x1a0 Read of size 4 at addr ffff88bbfe003524 by task kworker/u113:2/3039206 CPU: 0 PID: 3039206 Comm: kworker/u113:2 Kdump: loaded Not tainted 6.6.0+ Workqueue: pdecrypt_parallel padata_parallel_worker Call Trace: dump_stack_lvl+0x32/0x50 print_address_description.constprop.0+0x6b/0x3d0 print_report+0xdd/0x2c0 kasan_report+0xa5/0xd0 padata_find_next+0x29/0x1a0 padata_reorder+0x131/0x220 padata_parallel_worker+0x3d/0xc0 process_one_work+0x2ec/0x5a0 If 'mdelay(10)' is added before calling 'padata_find_next' in the 'padata_reorder' function, this issue could be reproduced easily with ltp test (pcrypt_aead01). This can be explained as bellow: pcrypt_aead_encrypt ... padata_do_parallel refcount_inc(&pd->refcnt); // add refcnt ... padata_do_serial padata_reorder // pd while (1) { padata_find_next(pd, true); // using pd queue_work_on ... padata_serial_worker crypto_del_alg padata_put_pd_cnt // sub refcnt padata_free_shell padata_put_pd(ps->pd); // pd is freed // loop again, but pd is freed // call padata_find_next, UAF } In the padata_reorder function, when it loops in 'while', if the alg is deleted, the refcnt may be decreased to 0 before entering 'padata_find_next', which leads to UAF. As mentioned in [1], do_serial is supposed to be called with BHs disabled and always happen under RCU protection, to address this issue, add synchronize_rcu() in 'padata_free_shell' wait for all _do_serial calls to finish. [1] https://lore.kernel.org/all/20221028160401.cccypv4euxikusiq@parnassus.localdomain/ [2] https://lore.kernel.org/linux-kernel/jfjz5d7zwbytztackem7ibzalm5lnxldi2eofeiczqmqs2m7o6@fq426cwnjtkm/ Fixes: b128a3040935 ("padata: allocate workqueue internally") Signed-off-by: Chen Ridong Signed-off-by: Qu Zicheng --- kernel/padata.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/padata.c b/kernel/padata.c index 7d79df1e3b33..de2c02a81469 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -1135,6 +1135,12 @@ void padata_free_shell(struct padata_shell *ps) if (!ps) return; + /* + * Wait for all _do_serial calls to finish to avoid touching + * freed pd's and ps's. + */ + synchronize_rcu(); + mutex_lock(&ps->pinst->lock); list_del(&ps->list); pd = rcu_dereference_protected(ps->pd, 1);