kernel/linux.git/drivers/mtd/ubi/eba.c, branch v6.19.11

ubi: eba: properly rollback inside self_check_eba

2024-07-12T17:42:46+00:00

In case of a memory allocation failure in the volumes loop we can only process the already allocated scan_eba and fm_eba array elements on the error path - others are still uninitialized. Found by Linux Verification Center (linuxtesting.org). Fixes: 00abf3041590 ("UBI: Add self_check_eba()") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fix slab-out-of-bounds in ubi_eba_get_ldesc+0xfb/0x130

2024-02-25T20:38:41+00:00

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 Signed-off-by: Richard Weinberger

ubi: fastmap: Wait until there are enough free PEBs before filling pools

2023-10-28T20:43:40+00:00

Wait until there are enough free PEBs before filling pool/wl_pool, sometimes erase_worker is not scheduled in time, which causes two situations: A. There are few PEBs filled in pool, which makes ubi_update_fastmap is frequently called and leads first 64 PEBs are erased more times than other PEBs. So waiting free PEBs before filling pool reduces fastmap updating frequency and prolongs flash service life. B. In situation that space is nearly running out, ubi_refill_pools() cannot make sure pool and wl_pool are filled with free PEBs, caused by the delay of erase_worker. After this patch applied, there must exist free PEBs in pool after one call of ubi_update_fastmap. Besides, this patch is a preparetion for fixing large erase counter in fastmap data block and fixing lapsed wear leveling for first 64 PEBs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Fix return value overwrite issue in try_write_vid_and_data()

2023-04-21T20:31:15+00:00

The commit 2d78aee426d8 ("UBI: simplify LEB write and atomic LEB change code") adds helper function, try_write_vid_and_data(), to simplify the code, but this helper function has bug, it will return 0 (success) when ubi_io_write_vid_hdr() or the ubi_io_write_data() return error number (-EIO, etc), because the return value of ubi_wl_put_peb() will overwrite the original return value. This issue will cause unexpected data loss issue, because the caller of this function and UBIFS willn't know the data is lost. Fixes: 2d78aee426d8 ("UBI: simplify LEB write and atomic LEB change code") Cc: stable@vger.kernel.org Signed-off-by: Wang YanQing Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: use correct names in function kernel-doc comments

2023-02-05T21:36:39+00:00

Fix kernel-doc warnings by using the correct function names in their kernel-doc notation: drivers/mtd/ubi/eba.c:72: warning: expecting prototype for next_sqnum(). Prototype was for ubi_next_sqnum() instead drivers/mtd/ubi/wl.c:176: warning: expecting prototype for wl_tree_destroy(). Prototype was for wl_entry_destroy() instead drivers/mtd/ubi/misc.c:24: warning: expecting prototype for calc_data_len(). Prototype was for ubi_calc_data_len() instead Signed-off-by: Randy Dunlap Cc: Richard Weinberger Cc: Miquel Raynal Cc: Vignesh Raghavendra Cc: linux-mtd@lists.infradead.org Signed-off-by: Richard Weinberger

ubi: Fix repeated words in comments

2022-09-21T09:32:27+00:00

Delete the redundant word 'a'. Delete the redundant word 'the'. Signed-off-by: Jilin Yuan Signed-off-by: Richard Weinberger

ubi: eba: Delete useless kfree code

2021-02-12T20:53:22+00:00

The parameter of kfree function is NULL, so kfree code is useless, delete it. Signed-off-by: Zheng Yongjun Signed-off-by: Richard Weinberger

mtd: ubi: eba: Fix a couple of misdocumentation issues

2020-11-20T11:37:31+00:00

Fixes the following W=1 kernel build warning(s): drivers/mtd/ubi/eba.c:1304: warning: Function parameter or member 'vidb' not described in 'ubi_eba_copy_leb' drivers/mtd/ubi/eba.c:1304: warning: Excess function parameter 'vid_hdr' description in 'ubi_eba_copy_leb' drivers/mtd/ubi/eba.c:1483: warning: Function parameter or member 'ai' not described in 'print_rsvd_warning' Cc: Richard Weinberger Cc: Miquel Raynal Cc: Vignesh Raghavendra Cc: linux-mtd@lists.infradead.org Signed-off-by: Lee Jones Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-12-lee.jones@linaro.org

treewide: Remove uninitialized_var() usage

2020-07-16T19:35:15+00:00

Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var$([^$]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman