From patchwork Sat Jan 13 13:06:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Zhaolong X-Patchwork-Id: 1886348 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=198.137.202.133; helo=bombadil.infradead.org; envelope-from=linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TBzPt1V2nz1yPy for ; Sun, 14 Jan 2024 00:14:08 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Fq0VvoMkCXChvJMmf1f3bIDd2+o9Awxx0XBZIIIrbag=; b=qpSfkvuRgsEgo7 Zho+L/UoHejtdt6L5AK8c9EeVYE/RTi4OXsuChClig/yPz5arEC1QsqeMHIkoajKaEyD1vCt4p+Km qD9STSSGAorqRZ/fTNDJ3fqcyYUFksSSUXn7xc57RksEUDjl+OjhelHvHqT8X988TdmMpFrB9Yb6q ecVu7YjEBhd1LaxrxoZWiq0NSXPJS98Xwx5TzLGYnddlJvUdSd1ips1MWLnzGjCeXP+JtVAGS6P34 gmqsFO8nT5ggDdVci2RL0Xw1l2ITFPvD18biz82QYUV/ePKfFdgoi6JcDtBk+lb2ULE3M1wbaRkUT B+iuGbDgREK2geNy3u/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rOdiX-005AM3-0z; Sat, 13 Jan 2024 13:06:29 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rOdiR-005AKQ-0v for linux-mtd@lists.infradead.org; Sat, 13 Jan 2024 13:06:25 +0000 Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4TBz7l2ySsz1FJ0F; Sat, 13 Jan 2024 21:01:55 +0800 (CST) Received: from dggpemd200001.china.huawei.com (unknown [7.185.36.224]) by mail.maildlp.com (Postfix) with ESMTPS id 37AA41A016B; Sat, 13 Jan 2024 21:06:05 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpemd200001.china.huawei.com (7.185.36.224) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1258.28; Sat, 13 Jan 2024 21:06:04 +0800 From: ZhaoLong Wang To: , , CC: , , , Subject: [PATCH v3 1/2] ubi: fix slab-out-of-bounds in ubi_eba_get_ldesc+0xfb/0x130 Date: Sat, 13 Jan 2024 21:06:00 +0800 Message-ID: <20240113130601.2502095-1-wangzhaolong1@huawei.com> X-Mailer: git-send-email 2.34.3 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemd200001.china.huawei.com (7.185.36.224) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240113_050623_670622_D43CC164 X-CRM114-Status: GOOD ( 19.02 ) X-Spam-Score: -1.3 (-) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: From: Guo Xuenan When using the ioctl interface to resize a UBI volume, `ubi_resize_volume` resizes the EBA table first but does not change `vol->reserved_pebs` in the same atomic context, which may cause concurrent a [...] Content analysis details: (-1.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.191 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 RCVD_IN_MSPIKE_H5 RBL: Excellent reputation (+5) [45.249.212.191 listed in wl.mailspike.net] 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders 1.0 HEXHASH_WORD Multiple instances of word + hexadecimal hash X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Guo Xuenan When using the ioctl interface to resize a UBI volume, `ubi_resize_volume` resizes the EBA table first but does not change `vol->reserved_pebs` in the same atomic context, which may cause concurrent access to the EBA table. For example, when a user shrinks UBI volume A by calling `ubi_resize_volume`, while another thread is writing to volume B and triggering wear-leveling, which may call `ubi_write_fastmap`, under these circumstances, KASAN may report a slab-out-of-bounds error in `ubi_eba_get_ldesc+0xfb/0x130`. This patch fixes race conditions in `ubi_resize_volume` and `ubi_update_fastmap` to avoid out-of-bounds reads of `eba_tbl`. First, it ensures that updates to `eba_tbl` and `reserved_pebs` are protected by `vol->volumes_lock`. Second, it implements a rollback mechanism in case of resize failure. It is also worth mentioning that for volume shrinkage failures, since part of the volume has already been shrunk and unmapped, there is no need to recover `{rsvd/avail}_pebs`. ================================================================== BUG: KASAN: slab-out-of-bounds in ubi_eba_get_ldesc+0xfb/0x130 [ubi] Read of size 4 at addr ffff88800f43f570 by task kworker/u16:0/7 CPU: 0 PID: 7 Comm: kworker/u16:0 Not tainted 5.16.0-rc7 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: writeback wb_workfn (flush-ubifs_0_0) Call Trace: dump_stack_lvl+0x4d/0x66 print_address_description.constprop.0+0x41/0x60 kasan_report.cold+0x83/0xdf ubi_eba_get_ldesc+0xfb/0x130 [ubi] ubi_update_fastmap.cold+0x60f/0xc7d [ubi] ubi_wl_get_peb+0x25b/0x4f0 [ubi] try_write_vid_and_data+0x9a/0x4d0 [ubi] ubi_eba_write_leb+0x7e4/0x17d0 [ubi] ubi_leb_map+0x1a0/0x2c0 [ubi] ubifs_leb_map+0x139/0x270 [ubifs] ubifs_add_bud_to_log+0xb40/0xf30 [ubifs] make_reservation+0x86e/0xb00 [ubifs] ubifs_jnl_write_data+0x430/0x9d0 [ubifs] do_writepage+0x1d1/0x550 [ubifs] ubifs_writepage+0x37c/0x670 [ubifs] __writepage+0x67/0x170 write_cache_pages+0x259/0xa90 do_writepages+0x277/0x5d0 __writeback_single_inode+0xb8/0x850 writeback_sb_inodes+0x4b3/0xb20 __writeback_inodes_wb+0xc1/0x220 wb_writeback+0x59f/0x740 wb_workfn+0x6d0/0xca0 process_one_work+0x711/0xfc0 worker_thread+0x95/0xd00 kthread+0x3a6/0x490 ret_from_fork+0x1f/0x30 Allocated by task 711: kasan_save_stack+0x1e/0x50 __kasan_kmalloc+0x81/0xa0 ubi_eba_create_table+0x88/0x1a0 [ubi] ubi_resize_volume.cold+0x175/0xae7 [ubi] ubi_cdev_ioctl+0x57f/0x1a60 [ubi] __x64_sys_ioctl+0x13a/0x1c0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x1e/0x50 __kasan_record_aux_stack+0xb7/0xc0 call_rcu+0xd6/0x1000 blk_stat_free_callback+0x28/0x30 blk_release_queue+0x8a/0x2e0 kobject_put+0x186/0x4c0 scsi_device_dev_release_usercontext+0x620/0xbd0 execute_in_process_context+0x2f/0x120 device_release+0xa4/0x240 kobject_put+0x186/0x4c0 put_device+0x20/0x30 __scsi_remove_device+0x1c3/0x300 scsi_probe_and_add_lun+0x2140/0x2eb0 __scsi_scan_target+0x1f2/0xbb0 scsi_scan_channel+0x11b/0x1a0 scsi_scan_host_selected+0x24c/0x310 do_scsi_scan_host+0x1e0/0x250 do_scan_async+0x45/0x490 async_run_entry_fn+0xa2/0x530 process_one_work+0x711/0xfc0 worker_thread+0x95/0xd00 kthread+0x3a6/0x490 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff88800f43f500 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 112 bytes inside of 128-byte region [ffff88800f43f500, ffff88800f43f580) The buggy address belongs to the page: page:ffffea00003d0f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xf43c head:ffffea00003d0f00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x1fffff80010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff) raw: 001fffff80010200 ffffea000046ba08 ffffea0000457208 ffff88810004d1c0 raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88800f43f400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800f43f480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff88800f43f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc ^ ffff88800f43f580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800f43f600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc The following steps can used to reproduce: Process 1: write and trigger ubi wear-leveling ubimkvol /dev/ubi0 -s 5000MiB -N v1 ubimkvol /dev/ubi0 -s 2000MiB -N v2 ubimkvol /dev/ubi0 -s 10MiB -N v3 mount -t ubifs /dev/ubi0_0 /mnt/ubifs while true; do filename=/mnt/ubifs/$((RANDOM)) dd if=/dev/random of=${filename} bs=1M count=$((RANDOM % 1000)) rm -rf ${filename} sync /mnt/ubifs/ done Process 2: do random resize struct ubi_rsvol_req req; req.vol_id = 1; req.bytes = (rand() % 50) * 512KB; ioctl(fd, UBI_IOCRSVOL, &req); V3: - Fix the commit message error. V2: - Add volumes_lock in ubi_eba_copy_leb() to avoid race caused by updating eba_tbl. V1: - Rebase the patch on the latest mainline. Signed-off-by: Guo Xuenan Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng --- drivers/mtd/ubi/eba.c | 7 +++++++ drivers/mtd/ubi/vmt.c | 24 +++++++++++++++++------- 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 8d1f0e05892c..e5ac3cd0bbae 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -1456,7 +1456,14 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, } ubi_assert(vol->eba_tbl->entries[lnum].pnum == from); + + /** + * The volumes_lock lock is needed here to prevent the expired old eba_tbl + * being updated when the eba_tbl is copied in the ubi_resize_volume() process. + */ + spin_lock(&ubi->volumes_lock); vol->eba_tbl->entries[lnum].pnum = to; + spin_unlock(&ubi->volumes_lock); out_unlock_buf: mutex_unlock(&ubi->buf_mutex); diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 2c867d16f89f..97294def01eb 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -408,6 +408,7 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) struct ubi_device *ubi = vol->ubi; struct ubi_vtbl_record vtbl_rec; struct ubi_eba_table *new_eba_tbl = NULL; + struct ubi_eba_table *old_eba_tbl = NULL; int vol_id = vol->vol_id; if (ubi->ro_mode) @@ -453,10 +454,13 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) err = -ENOSPC; goto out_free; } + ubi->avail_pebs -= pebs; ubi->rsvd_pebs += pebs; ubi_eba_copy_table(vol, new_eba_tbl, vol->reserved_pebs); - ubi_eba_replace_table(vol, new_eba_tbl); + old_eba_tbl = vol->eba_tbl; + vol->eba_tbl = new_eba_tbl; + vol->reserved_pebs = reserved_pebs; spin_unlock(&ubi->volumes_lock); } @@ -471,7 +475,9 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) ubi->avail_pebs -= pebs; ubi_update_reserved(ubi); ubi_eba_copy_table(vol, new_eba_tbl, reserved_pebs); - ubi_eba_replace_table(vol, new_eba_tbl); + old_eba_tbl = vol->eba_tbl; + vol->eba_tbl = new_eba_tbl; + vol->reserved_pebs = reserved_pebs; spin_unlock(&ubi->volumes_lock); } @@ -493,7 +499,6 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) if (err) goto out_acc; - vol->reserved_pebs = reserved_pebs; if (vol->vol_type == UBI_DYNAMIC_VOLUME) { vol->used_ebs = reserved_pebs; vol->last_eb_bytes = vol->usable_leb_size; @@ -501,19 +506,24 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) (long long)vol->used_ebs * vol->usable_leb_size; } + /* destroy old table */ + ubi_eba_destroy_table(old_eba_tbl); ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED); self_check_volumes(ubi); return err; out_acc: + spin_lock(&ubi->volumes_lock); + vol->reserved_pebs = reserved_pebs - pebs; if (pebs > 0) { - spin_lock(&ubi->volumes_lock); ubi->rsvd_pebs -= pebs; ubi->avail_pebs += pebs; - spin_unlock(&ubi->volumes_lock); + ubi_eba_copy_table(vol, old_eba_tbl, vol->reserved_pebs); + } else { + ubi_eba_copy_table(vol, old_eba_tbl, reserved_pebs); } - return err; - + vol->eba_tbl = old_eba_tbl; + spin_unlock(&ubi->volumes_lock); out_free: ubi_eba_destroy_table(new_eba_tbl); return err; From patchwork Sat Jan 13 13:06:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Zhaolong X-Patchwork-Id: 1886349 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=198.137.202.133; helo=bombadil.infradead.org; envelope-from=linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TBzPt25wpz1yQ5 for ; Sun, 14 Jan 2024 00:14:08 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Sat, 13 Jan 2024 21:06:05 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpemd200001.china.huawei.com (7.185.36.224) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1258.28; Sat, 13 Jan 2024 21:06:05 +0800 From: ZhaoLong Wang To: , , CC: , , , Subject: [PATCH v3 2/2] ubi: Correct the number of PEBs after a volume resize failure Date: Sat, 13 Jan 2024 21:06:01 +0800 Message-ID: <20240113130601.2502095-2-wangzhaolong1@huawei.com> X-Mailer: git-send-email 2.34.3 In-Reply-To: <20240113130601.2502095-1-wangzhaolong1@huawei.com> References: <20240113130601.2502095-1-wangzhaolong1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemd200001.china.huawei.com (7.185.36.224) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240113_050623_214219_3AE81E8A X-CRM114-Status: UNSURE ( 9.67 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.3 (--) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: In the error handling path `out_acc` of `ubi_resize_volume()`, when `pebs < 0`, it indicates that the volume table record failed to update when the volume was shrunk. In this case, the number of `ubi- [...] Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.190 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 RCVD_IN_MSPIKE_H4 RBL: Very Good reputation (+4) [45.249.212.190 listed in wl.mailspike.net] 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org In the error handling path `out_acc` of `ubi_resize_volume()`, when `pebs < 0`, it indicates that the volume table record failed to update when the volume was shrunk. In this case, the number of `ubi->avail_pebs` and `ubi->rsvd_pebs` should be restored to their previous values to prevent the UBI layer from reporting an incorrect number of available PEBs. Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng --- drivers/mtd/ubi/vmt.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 97294def01eb..990571287e84 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -515,13 +515,12 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) out_acc: spin_lock(&ubi->volumes_lock); vol->reserved_pebs = reserved_pebs - pebs; - if (pebs > 0) { - ubi->rsvd_pebs -= pebs; - ubi->avail_pebs += pebs; + ubi->rsvd_pebs -= pebs; + ubi->avail_pebs += pebs; + if (pebs > 0) ubi_eba_copy_table(vol, old_eba_tbl, vol->reserved_pebs); - } else { + else ubi_eba_copy_table(vol, old_eba_tbl, reserved_pebs); - } vol->eba_tbl = old_eba_tbl; spin_unlock(&ubi->volumes_lock); out_free: