[ Upstream commit 8c03a1c21d72210f81cb369cc528e3fde4b45411 ]
There is an use-after-free problem for 'eba_tbl' in ubi_create_volume()'s
error handling path:
ubi_eba_replace_table(vol, eba_tbl)
vol->eba_tbl = tbl
out_mapping:
ubi_eba_destroy_table(eba_tbl) // Free 'eba_tbl'
out_unlock:
put_device(&vol->dev)
vol_release
kfree(tbl->entries) // UAF
Fix it by removing redundant 'eba_tbl' releasing.
Fetch a reproducer in [Link].
Fixes: 493cfaeaa0c9b ("mtd: utilize new cdev_device_add helper function")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215965
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d09e9a2bddba6c48e0fddb16c4383172ac593251 ]
There at least 6 PEBs reserved on UBI device:
1. EBA_RESERVED_PEBS[1]
2. WL_RESERVED_PEBS[1]
3. UBI_LAYOUT_VOLUME_EBS[2]
4. MIN_FASTMAP_RESERVED_PEBS[2]
When all ubi volumes take all their PEBs, there are 3 (EBA_RESERVED_PEBS +
WL_RESERVED_PEBS + MIN_FASTMAP_RESERVED_PEBS - MIN_FASTMAP_TAKEN_PEBS[1])
free PEBs. Since commit f9c34bb529975fe ("ubi: Fix producing anchor PEBs")
and commit 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs considering
wear level rules") applied, there is only 1 (3 - FASTMAP_ANCHOR_PEBS[1] -
FASTMAP_NEXT_ANCHOR_PEBS[1]) free PEB to fill pool and wl_pool, after
filling pool, wl_pool is always empty. So, UBI could be stuck in an
infinite loop:
ubi_thread system_wq
wear_leveling_worker <--------------------------------------------------
get_peb_for_wl |
// fm_wl_pool, used = size = 0 |
schedule_work(&ubi->fm_work) |
|
update_fastmap_work_fn |
ubi_update_fastmap |
ubi_refill_pools |
// ubi->free_count - ubi->beb_rsvd_pebs < 5 |
// wl_pool is not filled with any PEBs |
schedule_erase(old_fm_anchor) |
ubi_ensure_anchor_pebs |
__schedule_ubi_work(wear_leveling_worker) |
|
__erase_worker |
ensure_wear_leveling |
__schedule_ubi_work(wear_leveling_worker) --------------------------
, which cause high cpu usage of ubi_bgt:
top - 12:10:42 up 5 min, 2 users, load average: 1.76, 0.68, 0.27
Tasks: 123 total, 3 running, 54 sleeping, 0 stopped, 0 zombie
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1589 root 20 0 0 0 0 R 45.0 0.0 0:38.86 ubi_bgt0d
319 root 20 0 0 0 0 I 15.2 0.0 0:15.29 kworker/0:3-eve
371 root 20 0 0 0 0 I 14.9 0.0 0:12.85 kworker/3:3-eve
20 root 20 0 0 0 0 I 11.3 0.0 0:05.33 kworker/1:0-eve
202 root 20 0 0 0 0 I 11.3 0.0 0:04.93 kworker/2:3-eve
In commit 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs considering
wear level rules"), there are three key changes:
1) Choose the fastmap anchor when the most free PEBs are available.
2) Enable anchor move within the anchor area again as it is useful
for distributing wear.
3) Import a candidate fm anchor and check this PEB's erase count during
wear leveling. If the wear leveling limit is exceeded, use the used
anchor area PEB with the lowest erase count to replace it.
The anchor candidate can be removed, we can check fm_anchor PEB's erase
count during wear leveling. Fix it by:
1) Removing 'fm_next_anchor' and check 'fm_anchor' during wear leveling.
2) Preferentially filling one free peb into fm_wl_pool in condition of
ubi->free_count > ubi->beb_rsvd_pebs, then try to reserve enough
free count for fastmap non anchor pebs after the above prerequisites
are met.
Then, there are at least 1 PEB in pool and 1 PEB in wl_pool after calling
ubi_refill_pools() with all erase works done.
Fetch a reproducer in [Link].
Fixes: 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs ... rules")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215407
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c3c07fc25f37c157fde041b3a0c3dfcb1590cbce upstream.
Abort fastmap scanning and return error code if memory allocation fails
in add_aeb(). Otherwise ubi will get wrong peb statistics information
after scanning.
Fixes: dbb7d2a88d2a7b ("UBI: Add fastmap core")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3cbf0e392f173ba0ce425968c8374a6aa3e90f2e upstream.
Hulk Robot reported a KASAN report about use-after-free:
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x13d/0x160
Read of size 8 at addr ffff888035e37d98 by task ubiattach/1385
[...]
Call Trace:
klist_dec_and_del+0xa7/0x4a0
klist_put+0xc7/0x1a0
device_del+0x4d4/0xed0
cdev_device_del+0x1a/0x80
ubi_attach_mtd_dev+0x2951/0x34b0 [ubi]
ctrl_cdev_ioctl+0x286/0x2f0 [ubi]
Allocated by task 1414:
device_add+0x60a/0x18b0
cdev_device_add+0x103/0x170
ubi_create_volume+0x1118/0x1a10 [ubi]
ubi_cdev_ioctl+0xb7f/0x1ba0 [ubi]
Freed by task 1385:
cdev_device_del+0x1a/0x80
ubi_remove_volume+0x438/0x6c0 [ubi]
ubi_cdev_ioctl+0xbf4/0x1ba0 [ubi]
[...]
==================================================================
The lock held by ctrl_cdev_ioctl is ubi_devices_mutex, but the lock held
by ubi_cdev_ioctl is ubi->device_mutex. Therefore, the two locks can be
concurrent.
ctrl_cdev_ioctl contains two operations: ubi_attach and ubi_detach.
ubi_detach is bug-free because it uses reference counting to prevent
concurrency. However, uif_init and uif_close in ubi_attach may race with
ubi_cdev_ioctl.
uif_init will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_add_volume
// sysfs exist
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
cdev_del
// double free
cdev_device_del
And uif_close will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_debugfs_init_dev
//error goto out_uif;
uif_close
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
// double free
The cause of this problem is that commit 714fb87e8bc0 make device
"available" before it becomes accessible via sysfs. Therefore, we
roll back the modification. We will fix the race condition between
ubi device creation and udev by removing ubi_get_device in
vol_attribute_show and dev_attribute_show.This avoids accessing
uninitialized ubi_devices[ubi_num].
ubi_get_device is used to prevent devices from being deleted during
sysfs execution. However, now kernfs ensures that devices will not
be deleted before all reference counting are released.
The key process is shown in the following stack.
device_del
device_remove_attrs
device_remove_groups
sysfs_remove_groups
sysfs_remove_group
remove_files
kernfs_remove_by_name
kernfs_remove_by_name_ns
__kernfs_remove
kernfs_drain
Fixes: 714fb87e8bc0 ("ubi: Fix race condition between ubi device creation and udev")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull block updates from Jens Axboe: - Unify where the struct request handling code is located in the blk-mq code (Christoph) - Header cleanups (Christoph) - Clean up the io_context handling code (Christoph, me) - Get rid of ->rq_disk in struct request (Christoph) - Error handling fix for add_disk() (Christoph) - request allocation cleanusp (Christoph) - Documentation updates (Eric, Matthew) - Remove trivial crypto unregister helper (Eric) - Reduce shared tag overhead (John) - Reduce poll_stats memory overhead (me) - Known indirect function call for dio (me) - Use atomic references for struct request (me) - Support request list issue for block and NVMe (me) - Improve queue dispatch pinning (Ming) - Improve the direct list issue code (Keith) - BFQ improvements (Jan) - Direct completion helper and use it in mmc block (Sebastian) - Use raw spinlock for the blktrace code (Wander) - fsync error handling fix (Ye) - Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me) * tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits) MAINTAINERS: add entries for block layer documentation docs: block: remove queue-sysfs.rst docs: sysfs-block: document virt_boundary_mask docs: sysfs-block: document stable_writes docs: sysfs-block: fill in missing documentation from queue-sysfs.rst docs: sysfs-block: add contact for nomerges docs: sysfs-block: sort alphabetically docs: sysfs-block: move to stable directory block: don't protect submit_bio_checks by q_usage_counter block: fix old-style declaration nvme-pci: fix queue_rqs list splitting block: introduce rq_list_move block: introduce rq_list_for_each_safe macro block: move rq_list macros to blk-mq.h block: drop needless assignment in set_task_ioprio() block: remove unnecessary trailing '\' bio.h: fix kernel-doc warnings block: check minor range in device_add_disk() block: use "unsigned long" for blk_validate_block_size(). block: fix error unwinding in device_add_disk ...
Fixes: 2a734bb8d502 ("UBI: use debugfs for the extra checks knobs")
There is a mistake in docstrings, it should be ubi_debugfs_exit_dev
instead of dbg_debug_exit_dev.
Signed-off-by: Kai Song <songkai01@inspur.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
All modern drivers can support extra partitions using the extended dev_t. In fact except for the ioctl method drivers never even see partitions in normal operation. So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all block devices that do support partitions, and require those that do not support partitions to explicit disallow them using GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
This function is trivial, and flush_dcache_page is always defined, so just open code it in the 2.5 callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20211103230437.1639990-10-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull UBIFS updates from Richard Weinberger:
- Fix for a race xattr list and modification
- Various minor fixes (spelling, return codes, ...)
* tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
ubifs: Set/Clear I_LINKABLE under i_lock for whiteout inode
ubifs: Fix spelling mistakes
ubifs: Remove ui_mutex in ubifs_xattr_get and change_xattr
ubifs: Fix races between xattr_{set|get} and listxattr operations
ubifs: fix snprintf() checking
ubifs: journal: Fix error return code in ubifs_jnl_write_inode()