In the Linux kernel, the following vulnerability has been resolved:
erofs: Fix detection of atomic context
Current check for atomic context is not sufficient as
z_erofs_decompressqueue_endio can be called under rcu lock
from blk_mq_flush_plug_list(). See the stacktrace [1]
In such case we should hand off the decompression work for async
processing rather than trying to do sync decompression in current
context. Patch fixes the detection by checking for
rcu_read_lock_any_held() and while at it use more appropriate
!in_task() check than in_atomic().
Background: Historically erofs would always schedule a kworker for
decompression which would incur the scheduling cost regardless of
the context. But z_erofs_decompressqueue_endio() may not always
be in atomic context and we could actually benefit from doing the
decompression in z_erofs_decompressqueue_endio() if we are in
thread context, for example when running with dm-verity.
This optimization was later added in patch [2] which has shown
improvement in performance benchmarks.
==============================================
[1] Problem stacktrace
[name:core&]BUG: sleeping function called from invalid context at kernel/locking/mutex.c:291
[name:core&]in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1615, name: CpuMonitorServi
[name:core&]preempt_count: 0, expected: 0
[name:core&]RCU nest depth: 1, expected: 0
CPU: 7 PID: 1615 Comm: CpuMonitorServi Tainted: G S W OE 6.1.25-android14-5-maybe-dirty-mainline #1
Hardware name: MT6897 (DT)
Call trace:
dump_backtrace+0x108/0x15c
show_stack+0x20/0x30
dump_stack_lvl+0x6c/0x8c
dump_stack+0x20/0x48
__might_resched+0x1fc/0x308
__might_sleep+0x50/0x88
mutex_lock+0x2c/0x110
z_erofs_decompress_queue+0x11c/0xc10
z_erofs_decompress_kickoff+0x110/0x1a4
z_erofs_decompressqueue_endio+0x154/0x180
bio_endio+0x1b0/0x1d8
__dm_io_complete+0x22c/0x280
clone_endio+0xe4/0x280
bio_endio+0x1b0/0x1d8
blk_update_request+0x138/0x3a4
blk_mq_plug_issue_direct+0xd4/0x19c
blk_mq_flush_plug_list+0x2b0/0x354
__blk_flush_plug+0x110/0x160
blk_finish_plug+0x30/0x4c
read_pages+0x2fc/0x370
page_cache_ra_unbounded+0xa4/0x23c
page_cache_ra_order+0x290/0x320
do_sync_mmap_readahead+0x108/0x2c0
filemap_fault+0x19c/0x52c
__do_fault+0xc4/0x114
handle_mm_fault+0x5b4/0x1168
do_page_fault+0x338/0x4b4
do_translation_fault+0x40/0x60
do_mem_abort+0x60/0xc8
el0_da+0x4c/0xe0
el0t_64_sync_handler+0xd4/0xfc
el0t_64_sync+0x1a0/0x1a4
[2] Link: https://lore.kernel.org/all/20210317035448.13921-1-huangjianan@oppo.com/
In the Linux kernel, the following vulnerability has been resolved:
phy: hisilicon: Fix an out of bounds check in hisi_inno_phy_probe()
The size of array 'priv->ports[]' is INNO_PHY_PORT_NUM.
In the for loop, 'i' is used as the index for array 'priv->ports[]'
with a check (i > INNO_PHY_PORT_NUM) which indicates that
INNO_PHY_PORT_NUM is allowed value for 'i' in the same loop.
This > comparison needs to be changed to >=, otherwise it potentially leads
to an out of bounds write on the next iteration through the loop
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dsi: Add missing check for alloc_ordered_workqueue
Add check for the return value of alloc_ordered_workqueue as it may return
NULL pointer and cause NULL pointer dereference.
Patchwork: https://patchwork.freedesktop.org/patch/517646/
In the Linux kernel, the following vulnerability has been resolved:
ext4: Fix function prototype mismatch for ext4_feat_ktype
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed.
ext4_feat_ktype was setting the "release" handler to "kfree", which
doesn't have a matching function prototype. Add a simple wrapper
with the correct prototype.
This was found as a result of Clang's new -Wcast-function-type-strict
flag, which is more sensitive than the simpler -Wcast-function-type,
which only checks for type width mismatches.
Note that this code is only reached when ext4 is a loadable module and
it is being unloaded:
CFI failure at kobject_put+0xbb/0x1b0 (target: kfree+0x0/0x180; expected type: 0x7c4aa698)
...
RIP: 0010:kobject_put+0xbb/0x1b0
...
Call Trace:
<TASK>
ext4_exit_sysfs+0x14/0x60 [ext4]
cleanup_module+0x67/0xedb [ext4]
In the Linux kernel, the following vulnerability has been resolved:
spi: imx: Don't skip cleanup in remove's error path
Returning early in a platform driver's remove callback is wrong. In this
case the dma resources are not released in the error path. this is never
retried later and so this is a permanent leak. To fix this, only skip
hardware disabling if waking the device fails.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mwifiex: Fix OOB and integer underflow when rx packets
Make sure mwifiex_process_mgmt_packet,
mwifiex_process_sta_rx_packet and mwifiex_process_uap_rx_packet,
mwifiex_uap_queue_bridged_pkt and mwifiex_process_rx_packet
not out-of-bounds access the skb->data buffer.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix invalid drv_sta_pre_rcu_remove calls for non-uploaded sta
Avoid potential data corruption issues caused by uninitialized driver
private data structures.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix warning in cifs_smb3_do_mount()
This fixes the following warning reported by kernel test robot
fs/smb/client/cifsfs.c:982 cifs_smb3_do_mount() warn: possible
memory leak of 'cifs_sb'
In the Linux kernel, the following vulnerability has been resolved:
sched/fair: Don't balance task to its current running CPU
We've run into the case that the balancer tries to balance a migration
disabled task and trigger the warning in set_task_cpu() like below:
------------[ cut here ]------------
WARNING: CPU: 7 PID: 0 at kernel/sched/core.c:3115 set_task_cpu+0x188/0x240
Modules linked in: hclgevf xt_CHECKSUM ipt_REJECT nf_reject_ipv4 <...snip>
CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G O 6.1.0-rc4+ #1
Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V5.B221.01 12/09/2021
pstate: 604000c9 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : set_task_cpu+0x188/0x240
lr : load_balance+0x5d0/0xc60
sp : ffff80000803bc70
x29: ffff80000803bc70 x28: ffff004089e190e8 x27: ffff004089e19040
x26: ffff007effcabc38 x25: 0000000000000000 x24: 0000000000000001
x23: ffff80000803be84 x22: 000000000000000c x21: ffffb093e79e2a78
x20: 000000000000000c x19: ffff004089e19040 x18: 0000000000000000
x17: 0000000000001fad x16: 0000000000000030 x15: 0000000000000000
x14: 0000000000000003 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000400 x9 : ffffb093e4cee530
x8 : 00000000fffffffe x7 : 0000000000ce168a x6 : 000000000000013e
x5 : 00000000ffffffe1 x4 : 0000000000000001 x3 : 0000000000000b2a
x2 : 0000000000000b2a x1 : ffffb093e6d6c510 x0 : 0000000000000001
Call trace:
set_task_cpu+0x188/0x240
load_balance+0x5d0/0xc60
rebalance_domains+0x26c/0x380
_nohz_idle_balance.isra.0+0x1e0/0x370
run_rebalance_domains+0x6c/0x80
__do_softirq+0x128/0x3d8
____do_softirq+0x18/0x24
call_on_irq_stack+0x2c/0x38
do_softirq_own_stack+0x24/0x3c
__irq_exit_rcu+0xcc/0xf4
irq_exit_rcu+0x18/0x24
el1_interrupt+0x4c/0xe4
el1h_64_irq_handler+0x18/0x2c
el1h_64_irq+0x74/0x78
arch_cpu_idle+0x18/0x4c
default_idle_call+0x58/0x194
do_idle+0x244/0x2b0
cpu_startup_entry+0x30/0x3c
secondary_start_kernel+0x14c/0x190
__secondary_switched+0xb0/0xb4
---[ end trace 0000000000000000 ]---
Further investigation shows that the warning is superfluous, the migration
disabled task is just going to be migrated to its current running CPU.
This is because that on load balance if the dst_cpu is not allowed by the
task, we'll re-select a new_dst_cpu as a candidate. If no task can be
balanced to dst_cpu we'll try to balance the task to the new_dst_cpu
instead. In this case when the migration disabled task is not on CPU it
only allows to run on its current CPU, load balance will select its
current CPU as new_dst_cpu and later triggers the warning above.
The new_dst_cpu is chosen from the env->dst_grpmask. Currently it
contains CPUs in sched_group_span() and if we have overlapped groups it's
possible to run into this case. This patch makes env->dst_grpmask of
group_balance_mask() which exclude any CPUs from the busiest group and
solve the issue. For balancing in a domain with no overlapped groups
the behaviour keeps same as before.