Security Vulnerabilities
- CVEs Published In April 2024
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected
For those endpoint devices connect to system via hotplug capable ports,
users could request a hot reset to the device by flapping device's link
through setting the slot's link control register, as pciehp_ist() DLLSC
interrupt sequence response, pciehp will unload the device driver and
then power it off. thus cause an IOMMU device-TLB invalidation (Intel
VT-d spec, or ATS Invalidation in PCIe spec r6.1) request for non-existence
target device to be sent and deadly loop to retry that request after ITE
fault triggered in interrupt context.
That would cause following continuous hard lockup warning and system hang
[ 4211.433662] pcieport 0000:17:01.0: pciehp: Slot(108): Link Down
[ 4211.433664] pcieport 0000:17:01.0: pciehp: Slot(108): Card not present
[ 4223.822591] NMI watchdog: Watchdog detected hard LOCKUP on cpu 144
[ 4223.822622] CPU: 144 PID: 1422 Comm: irq/57-pciehp Kdump: loaded Tainted: G S
OE kernel version xxxx
[ 4223.822623] Hardware name: vendorname xxxx 666-106,
BIOS 01.01.02.03.01 05/15/2023
[ 4223.822623] RIP: 0010:qi_submit_sync+0x2c0/0x490
[ 4223.822624] Code: 48 be 00 00 00 00 00 08 00 00 49 85 74 24 20 0f 95 c1 48 8b
57 10 83 c1 04 83 3c 1a 03 0f 84 a2 01 00 00 49 8b 04 24 8b 70 34 <40> f6 c6 1
0 74 17 49 8b 04 24 8b 80 80 00 00 00 89 c2 d3 fa 41 39
[ 4223.822624] RSP: 0018:ffffc4f074f0bbb8 EFLAGS: 00000093
[ 4223.822625] RAX: ffffc4f040059000 RBX: 0000000000000014 RCX: 0000000000000005
[ 4223.822625] RDX: ffff9f3841315800 RSI: 0000000000000000 RDI: ffff9f38401a8340
[ 4223.822625] RBP: ffff9f38401a8340 R08: ffffc4f074f0bc00 R09: 0000000000000000
[ 4223.822626] R10: 0000000000000010 R11: 0000000000000018 R12: ffff9f384005e200
[ 4223.822626] R13: 0000000000000004 R14: 0000000000000046 R15: 0000000000000004
[ 4223.822626] FS: 0000000000000000(0000) GS:ffffa237ae400000(0000)
knlGS:0000000000000000
[ 4223.822627] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4223.822627] CR2: 00007ffe86515d80 CR3: 000002fd3000a001 CR4: 0000000000770ee0
[ 4223.822627] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4223.822628] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[ 4223.822628] PKRU: 55555554
[ 4223.822628] Call Trace:
[ 4223.822628] qi_flush_dev_iotlb+0xb1/0xd0
[ 4223.822628] __dmar_remove_one_dev_info+0x224/0x250
[ 4223.822629] dmar_remove_one_dev_info+0x3e/0x50
[ 4223.822629] intel_iommu_release_device+0x1f/0x30
[ 4223.822629] iommu_release_device+0x33/0x60
[ 4223.822629] iommu_bus_notifier+0x7f/0x90
[ 4223.822630] blocking_notifier_call_chain+0x60/0x90
[ 4223.822630] device_del+0x2e5/0x420
[ 4223.822630] pci_remove_bus_device+0x70/0x110
[ 4223.822630] pciehp_unconfigure_device+0x7c/0x130
[ 4223.822631] pciehp_disable_slot+0x6b/0x100
[ 4223.822631] pciehp_handle_presence_or_link_change+0xd8/0x320
[ 4223.822631] pciehp_ist+0x176/0x180
[ 4223.822631] ? irq_finalize_oneshot.part.50+0x110/0x110
[ 4223.822632] irq_thread_fn+0x19/0x50
[ 4223.822632] irq_thread+0x104/0x190
[ 4223.822632] ? irq_forced_thread_fn+0x90/0x90
[ 4223.822632] ? irq_thread_check_affinity+0xe0/0xe0
[ 4223.822633] kthread+0x114/0x130
[ 4223.822633] ? __kthread_cancel_work+0x40/0x40
[ 4223.822633] ret_from_fork+0x1f/0x30
[ 4223.822633] Kernel panic - not syncing: Hard LOCKUP
[ 4223.822634] CPU: 144 PID: 1422 Comm: irq/57-pciehp Kdump: loaded Tainted: G S
OE kernel version xxxx
[ 4223.822634] Hardware name: vendorname xxxx 666-106,
BIOS 01.01.02.03.01 05/15/2023
[ 4223.822634] Call Trace:
[ 4223.822634] <NMI>
[ 4223.822635] dump_stack+0x6d/0x88
[ 4223.822635] panic+0x101/0x2d0
[ 4223.822635] ? ret_from_fork+0x11/0x30
[ 4223.822635] nmi_panic.cold.14+0xc/0xc
[ 4223.822636] watchdog_overflow_callback.cold.8+0x6d/0x81
[ 4223.822636] __perf_event_overflow+0x4f/0xf0
[ 4223.822636] handle_pmi_common
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7921e: fix use-after-free in free_irq()
From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test
to make sure the shared irq handler should be able to handle the unexpected
event after deregistration. For this case, let's apply MT76_REMOVED flag to
indicate the device was removed and do not run into the resource access
anymore.
BUG: KASAN: use-after-free in mt7921_irq_handler+0xd8/0x100 [mt7921e]
Read of size 8 at addr ffff88824a7d3b78 by task rmmod/11115
CPU: 28 PID: 11115 Comm: rmmod Tainted: G W L 5.17.0 #10
Hardware name: Micro-Star International Co., Ltd. MS-7D73/MPG B650I
EDGE WIFI (MS-7D73), BIOS 1.81 01/05/2024
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xa0
print_address_description.constprop.0+0x1f/0x190
? mt7921_irq_handler+0xd8/0x100 [mt7921e]
? mt7921_irq_handler+0xd8/0x100 [mt7921e]
kasan_report.cold+0x7f/0x11b
? mt7921_irq_handler+0xd8/0x100 [mt7921e]
mt7921_irq_handler+0xd8/0x100 [mt7921e]
free_irq+0x627/0xaa0
devm_free_irq+0x94/0xd0
? devm_request_any_context_irq+0x160/0x160
? kobject_put+0x18d/0x4a0
mt7921_pci_remove+0x153/0x190 [mt7921e]
pci_device_remove+0xa2/0x1d0
__device_release_driver+0x346/0x6e0
driver_detach+0x1ef/0x2c0
bus_remove_driver+0xe7/0x2d0
? __check_object_size+0x57/0x310
pci_unregister_driver+0x26/0x250
__do_sys_delete_module+0x307/0x510
? free_module+0x6a0/0x6a0
? fpregs_assert_state_consistent+0x4b/0xb0
? rcu_read_lock_sched_held+0x10/0x70
? syscall_enter_from_user_mode+0x20/0x70
? trace_hardirqs_on+0x1c/0x130
do_syscall_64+0x5c/0x80
? trace_hardirqs_on_prepare+0x72/0x160
? do_syscall_64+0x68/0x80
? trace_hardirqs_on_prepare+0x72/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xae
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Fix double free in SMC transport cleanup path
When the generic SCMI code tears down a channel, it calls the chan_free
callback function, defined by each transport. Since multiple protocols
might share the same transport_info member, chan_free() might want to
clean up the same member multiple times within the given SCMI transport
implementation. In this case, it is SMC transport. This will lead to a NULL
pointer dereference at the second time:
| scmi_protocol scmi_dev.1: Enabled polling mode TX channel - prot_id:16
| arm-scmi firmware:scmi: SCMI Notifications - Core Enabled.
| arm-scmi firmware:scmi: unable to communicate with SCMI
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
| ESR = 0x0000000096000004
| EC = 0x25: DABT (current EL), IL = 32 bits
| SET = 0, FnV = 0
| EA = 0, S1PTW = 0
| FSC = 0x04: level 0 translation fault
| Data abort info:
| ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
| CM = 0, WnR = 0, TnD = 0, TagAccess = 0
| GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
| user pgtable: 4k pages, 48-bit VAs, pgdp=0000000881ef8000
| [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
| Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 4 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc2-00124-g455ef3d016c9-dirty #793
| Hardware name: FVP Base RevC (DT)
| pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : smc_chan_free+0x3c/0x6c
| lr : smc_chan_free+0x3c/0x6c
| Call trace:
| smc_chan_free+0x3c/0x6c
| idr_for_each+0x68/0xf8
| scmi_cleanup_channels.isra.0+0x2c/0x58
| scmi_probe+0x434/0x734
| platform_probe+0x68/0xd8
| really_probe+0x110/0x27c
| __driver_probe_device+0x78/0x12c
| driver_probe_device+0x3c/0x118
| __driver_attach+0x74/0x128
| bus_for_each_dev+0x78/0xe0
| driver_attach+0x24/0x30
| bus_add_driver+0xe4/0x1e8
| driver_register+0x60/0x128
| __platform_driver_register+0x28/0x34
| scmi_driver_init+0x84/0xc0
| do_one_initcall+0x78/0x33c
| kernel_init_freeable+0x2b8/0x51c
| kernel_init+0x24/0x130
| ret_from_fork+0x10/0x20
| Code: f0004701 910a0021 aa1403e5 97b91c70 (b9400280)
| ---[ end trace 0000000000000000 ]---
Simply check for the struct pointer being NULL before trying to access
its members, to avoid this situation.
This was found when a transport doesn't really work (for instance no SMC
service), the probe routines then tries to clean up, and triggers a crash.
In the Linux kernel, the following vulnerability has been resolved:
ACPI: processor_idle: Fix memory leak in acpi_processor_power_exit()
After unregistering the CPU idle device, the memory associated with
it is not freed, leading to a memory leak:
unreferenced object 0xffff896282f6c000 (size 1024):
comm "swapper/0", pid 1, jiffies 4294893170
hex dump (first 32 bytes):
00 00 00 00 0b 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8836a742):
[<ffffffff993495ed>] kmalloc_trace+0x29d/0x340
[<ffffffff9972f3b3>] acpi_processor_power_init+0xf3/0x1c0
[<ffffffff9972d263>] __acpi_processor_start+0xd3/0xf0
[<ffffffff9972d2bc>] acpi_processor_start+0x2c/0x50
[<ffffffff99805872>] really_probe+0xe2/0x480
[<ffffffff99805c98>] __driver_probe_device+0x78/0x160
[<ffffffff99805daf>] driver_probe_device+0x1f/0x90
[<ffffffff9980601e>] __driver_attach+0xce/0x1c0
[<ffffffff99803170>] bus_for_each_dev+0x70/0xc0
[<ffffffff99804822>] bus_add_driver+0x112/0x210
[<ffffffff99807245>] driver_register+0x55/0x100
[<ffffffff9aee4acb>] acpi_processor_driver_init+0x3b/0xc0
[<ffffffff990012d1>] do_one_initcall+0x41/0x300
[<ffffffff9ae7c4b0>] kernel_init_freeable+0x320/0x470
[<ffffffff99b231f6>] kernel_init+0x16/0x1b0
[<ffffffff99042e6d>] ret_from_fork+0x2d/0x50
Fix this by freeing the CPU idle device after unregistering it.
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: prevent use-after-free on vif when cleaning up all interfaces
wilc_netdev_cleanup currently triggers a KASAN warning, which can be
observed on interface registration error path, or simply by
removing the module/unbinding device from driver:
echo spi0.1 > /sys/bus/spi/drivers/wilc1000_spi/unbind
==================================================================
BUG: KASAN: slab-use-after-free in wilc_netdev_cleanup+0x508/0x5cc
Read of size 4 at addr c54d1ce8 by task sh/86
CPU: 0 PID: 86 Comm: sh Not tainted 6.8.0-rc1+ #117
Hardware name: Atmel SAMA5
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x58
dump_stack_lvl from print_report+0x154/0x500
print_report from kasan_report+0xac/0xd8
kasan_report from wilc_netdev_cleanup+0x508/0x5cc
wilc_netdev_cleanup from wilc_bus_remove+0xc8/0xec
wilc_bus_remove from spi_remove+0x8c/0xac
spi_remove from device_release_driver_internal+0x434/0x5f8
device_release_driver_internal from unbind_store+0xbc/0x108
unbind_store from kernfs_fop_write_iter+0x398/0x584
kernfs_fop_write_iter from vfs_write+0x728/0xf88
vfs_write from ksys_write+0x110/0x1e4
ksys_write from ret_fast_syscall+0x0/0x1c
[...]
Allocated by task 1:
kasan_save_track+0x30/0x5c
__kasan_kmalloc+0x8c/0x94
__kmalloc_node+0x1cc/0x3e4
kvmalloc_node+0x48/0x180
alloc_netdev_mqs+0x68/0x11dc
alloc_etherdev_mqs+0x28/0x34
wilc_netdev_ifc_init+0x34/0x8ec
wilc_cfg80211_init+0x690/0x910
wilc_bus_probe+0xe0/0x4a0
spi_probe+0x158/0x1b0
really_probe+0x270/0xdf4
__driver_probe_device+0x1dc/0x580
driver_probe_device+0x60/0x140
__driver_attach+0x228/0x5d4
bus_for_each_dev+0x13c/0x1a8
bus_add_driver+0x2a0/0x608
driver_register+0x24c/0x578
do_one_initcall+0x180/0x310
kernel_init_freeable+0x424/0x484
kernel_init+0x20/0x148
ret_from_fork+0x14/0x28
Freed by task 86:
kasan_save_track+0x30/0x5c
kasan_save_free_info+0x38/0x58
__kasan_slab_free+0xe4/0x140
kfree+0xb0/0x238
device_release+0xc0/0x2a8
kobject_put+0x1d4/0x46c
netdev_run_todo+0x8fc/0x11d0
wilc_netdev_cleanup+0x1e4/0x5cc
wilc_bus_remove+0xc8/0xec
spi_remove+0x8c/0xac
device_release_driver_internal+0x434/0x5f8
unbind_store+0xbc/0x108
kernfs_fop_write_iter+0x398/0x584
vfs_write+0x728/0xf88
ksys_write+0x110/0x1e4
ret_fast_syscall+0x0/0x1c
[...]
David Mosberger-Tan initial investigation [1] showed that this
use-after-free is due to netdevice unregistration during vif list
traversal. When unregistering a net device, since the needs_free_netdev has
been set to true during registration, the netdevice object is also freed,
and as a consequence, the corresponding vif object too, since it is
attached to it as private netdevice data. The next occurrence of the loop
then tries to access freed vif pointer to the list to move forward in the
list.
Fix this use-after-free thanks to two mechanisms:
- navigate in the list with list_for_each_entry_safe, which allows to
safely modify the list as we go through each element. For each element,
remove it from the list with list_del_rcu
- make sure to wait for RCU grace period end after each vif removal to make
sure it is safe to free the corresponding vif too (through
unregister_netdev)
Since we are in a RCU "modifier" path (not a "reader" path), and because
such path is expected not to be concurrent to any other modifier (we are
using the vif_mutex lock), we do not need to use RCU list API, that's why
we can benefit from list_for_each_entry_safe.
[1] https://lore.kernel.org/linux-wireless/ab077dbe58b1ea5de0a3b2ca21f275a07af967d2.camel@egauge.net/
In the Linux kernel, the following vulnerability has been resolved:
wifi: wfx: fix memory leak when starting AP
Kmemleak reported this error:
unreferenced object 0xd73d1180 (size 184):
comm "wpa_supplicant", pid 1559, jiffies 13006305 (age 964.245s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 1e 00 01 00 00 00 00 00 ................
backtrace:
[<5ca11420>] kmem_cache_alloc+0x20c/0x5ac
[<127bdd74>] __alloc_skb+0x144/0x170
[<fb8a5e38>] __netdev_alloc_skb+0x50/0x180
[<0f9fa1d5>] __ieee80211_beacon_get+0x290/0x4d4 [mac80211]
[<7accd02d>] ieee80211_beacon_get_tim+0x54/0x18c [mac80211]
[<41e25cc3>] wfx_start_ap+0xc8/0x234 [wfx]
[<93a70356>] ieee80211_start_ap+0x404/0x6b4 [mac80211]
[<a4a661cd>] nl80211_start_ap+0x76c/0x9e0 [cfg80211]
[<47bd8b68>] genl_rcv_msg+0x198/0x378
[<453ef796>] netlink_rcv_skb+0xd0/0x130
[<6b7c977a>] genl_rcv+0x34/0x44
[<66b2d04d>] netlink_unicast+0x1b4/0x258
[<f965b9b6>] netlink_sendmsg+0x1e8/0x428
[<aadb8231>] ____sys_sendmsg+0x1e0/0x274
[<d2b5212d>] ___sys_sendmsg+0x80/0xb4
[<69954f45>] __sys_sendmsg+0x64/0xa8
unreferenced object 0xce087000 (size 1024):
comm "wpa_supplicant", pid 1559, jiffies 13006305 (age 964.246s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
10 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<9a993714>] __kmalloc_track_caller+0x230/0x600
[<f83ea192>] kmalloc_reserve.constprop.0+0x30/0x74
[<a2c61343>] __alloc_skb+0xa0/0x170
[<fb8a5e38>] __netdev_alloc_skb+0x50/0x180
[<0f9fa1d5>] __ieee80211_beacon_get+0x290/0x4d4 [mac80211]
[<7accd02d>] ieee80211_beacon_get_tim+0x54/0x18c [mac80211]
[<41e25cc3>] wfx_start_ap+0xc8/0x234 [wfx]
[<93a70356>] ieee80211_start_ap+0x404/0x6b4 [mac80211]
[<a4a661cd>] nl80211_start_ap+0x76c/0x9e0 [cfg80211]
[<47bd8b68>] genl_rcv_msg+0x198/0x378
[<453ef796>] netlink_rcv_skb+0xd0/0x130
[<6b7c977a>] genl_rcv+0x34/0x44
[<66b2d04d>] netlink_unicast+0x1b4/0x258
[<f965b9b6>] netlink_sendmsg+0x1e8/0x428
[<aadb8231>] ____sys_sendmsg+0x1e0/0x274
[<d2b5212d>] ___sys_sendmsg+0x80/0xb4
However, since the kernel is build optimized, it seems the stack is not
accurate. It appears the issue is related to wfx_set_mfp_ap(). The issue
is obvious in this function: memory allocated by ieee80211_beacon_get()
is never released. Fixing this leak makes kmemleak happy.
In the Linux kernel, the following vulnerability has been resolved:
aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts
This patch is against CVE-2023-6270. The description of cve is:
A flaw was found in the ATA over Ethernet (AoE) driver in the Linux
kernel. The aoecmd_cfg_pkts() function improperly updates the refcnt on
`struct net_device`, and a use-after-free can be triggered by racing
between the free on the struct and the access through the `skbtxq`
global queue. This could lead to a denial of service condition or
potential code execution.
In aoecmd_cfg_pkts(), it always calls dev_put(ifp) when skb initial
code is finished. But the net_device ifp will still be used in
later tx()->dev_queue_xmit() in kthread. Which means that the
dev_put(ifp) should NOT be called in the success path of skb
initial code in aoecmd_cfg_pkts(). Otherwise tx() may run into
use-after-free because the net_device is freed.
This patch removed the dev_put(ifp) in the success path in
aoecmd_cfg_pkts(), and added dev_put() after skb xmit in tx().
In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between bd_link_disk_holder and partition scan
'open_mutex' of gendisk is used to protect open/close block devices. But
in bd_link_disk_holder(), it is used to protect the creation of symlink
between holding disk and slave bdev, which introduces some issues.
When bd_link_disk_holder() is called, the driver is usually in the process
of initialization/modification and may suspend submitting io. At this
time, any io hold 'open_mutex', such as scanning partitions, can cause
deadlocks. For example, in raid:
T1 T2
bdev_open_by_dev
lock open_mutex [1]
...
efi_partition
...
md_submit_bio
md_ioctl mddev_syspend
-> suspend all io
md_add_new_disk
bind_rdev_to_array
bd_link_disk_holder
try lock open_mutex [2]
md_handle_request
-> wait mddev_resume
T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume
mddev, but T2 waits for open_mutex held by T1. Deadlock occurs.
Fix it by introducing a local mutex 'blk_holder_mutex' to replace
'open_mutex'.
In the Linux kernel, the following vulnerability has been resolved:
md: fix kmemleak of rdev->serial
If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be
alloc not be freed, and kmemleak occurs.
unreferenced object 0xffff88815a350000 (size 49152):
comm "mdadm", pid 789, jiffies 4294716910
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc f773277a):
[<0000000058b0a453>] kmemleak_alloc+0x61/0xe0
[<00000000366adf14>] __kmalloc_large_node+0x15e/0x270
[<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f
[<00000000f206d60a>] kvmalloc_node+0x74/0x150
[<0000000034bf3363>] rdev_init_serial+0x67/0x170
[<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220
[<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630
[<0000000073c28560>] md_add_new_disk+0x400/0x9f0
[<00000000770e30ff>] md_ioctl+0x15bf/0x1c10
[<000000006cfab718>] blkdev_ioctl+0x191/0x3f0
[<0000000085086a11>] vfs_ioctl+0x22/0x60
[<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0
[<00000000e54e675e>] do_syscall_64+0x71/0x150
[<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74
In the Linux kernel, the following vulnerability has been resolved:
do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak
syzbot identified a kernel information leak vulnerability in
do_sys_name_to_handle() and issued the following report [1].
[1]
"BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
_copy_to_user+0xbc/0x100 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:191 [inline]
do_sys_name_to_handle fs/fhandle.c:73 [inline]
__do_sys_name_to_handle_at fs/fhandle.c:112 [inline]
__se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94
__x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94
...
Uninit was created at:
slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
slab_alloc_node mm/slub.c:3478 [inline]
__kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0x121/0x3c0 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
do_sys_name_to_handle fs/fhandle.c:39 [inline]
__do_sys_name_to_handle_at fs/fhandle.c:112 [inline]
__se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94
__x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94
...
Bytes 18-19 of 20 are uninitialized
Memory access of size 20 starts at ffff888128a46380
Data copied to user address 0000000020000240"
Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to
solve the problem.