In the Linux kernel, the following vulnerability has been resolved:
ASoC: core: Fix use-after-free in snd_soc_exit()
KASAN reports a use-after-free:
BUG: KASAN: use-after-free in device_del+0xb5b/0xc60
Read of size 8 at addr ffff888008655050 by task rmmod/387
CPU: 2 PID: 387 Comm: rmmod
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl+0x79/0x9a
print_report+0x17f/0x47b
kasan_report+0xbb/0xf0
device_del+0xb5b/0xc60
platform_device_del.part.0+0x24/0x200
platform_device_unregister+0x2e/0x40
snd_soc_exit+0xa/0x22 [snd_soc_core]
__do_sys_delete_module.constprop.0+0x34f/0x5b0
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
It's bacause in snd_soc_init(), snd_soc_util_init() is possble to fail,
but its ret is ignored, which makes soc_dummy_dev unregistered twice.
snd_soc_init()
snd_soc_util_init()
platform_device_register_simple(soc_dummy_dev)
platform_driver_register() # fail
platform_device_unregister(soc_dummy_dev)
platform_driver_register() # success
...
snd_soc_exit()
snd_soc_util_exit()
# soc_dummy_dev will be unregistered for second time
To fix it, handle error and stop snd_soc_init() when util_init() fail.
Also clean debugfs when util_init() or driver_register() fail.
In the Linux kernel, the following vulnerability has been resolved:
hugetlbfs: don't delete error page from pagecache
This change is very similar to the change that was made for shmem [1], and
it solves the same problem but for HugeTLBFS instead.
Currently, when poison is found in a HugeTLB page, the page is removed
from the page cache. That means that attempting to map or read that
hugepage in the future will result in a new hugepage being allocated
instead of notifying the user that the page was poisoned. As [1] states,
this is effectively memory corruption.
The fix is to leave the page in the page cache. If the user attempts to
use a poisoned HugeTLB page with a syscall, the syscall will fail with
EIO, the same error code that shmem uses. For attempts to map the page,
the thread will get a BUS_MCEERR_AR SIGBUS.
[1]: commit a76054266661 ("mm: shmem: don't truncate page if memory failure happens")
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: initialize device's zone info for seeding
When performing seeding on a zoned filesystem it is necessary to
initialize each zoned device's btrfs_zoned_device_info structure,
otherwise mounting the filesystem will cause a NULL pointer dereference.
This was uncovered by fstests' testcase btrfs/163.
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix use-after-free bug of ns_writer on remount
If a nilfs2 filesystem is downgraded to read-only due to metadata
corruption on disk and is remounted read/write, or if emergency read-only
remount is performed, detaching a log writer and synchronizing the
filesystem can be done at the same time.
In these cases, use-after-free of the log writer (hereinafter
nilfs->ns_writer) can happen as shown in the scenario below:
Task1 Task2
-------------------------------- ------------------------------
nilfs_construct_segment
nilfs_segctor_sync
init_wait
init_waitqueue_entry
add_wait_queue
schedule
nilfs_remount (R/W remount case)
nilfs_attach_log_writer
nilfs_detach_log_writer
nilfs_segctor_destroy
kfree
finish_wait
_raw_spin_lock_irqsave
__raw_spin_lock_irqsave
do_raw_spin_lock
debug_spin_lock_before <-- use-after-free
While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1
waked up, Task1 accesses nilfs->ns_writer which is already freed. This
scenario diagram is based on the Shigeru Yoshida's post [1].
This patch fixes the issue by not detaching nilfs->ns_writer on remount so
that this UAF race doesn't happen. Along with this change, this patch
also inserts a few necessary read-only checks with superblock instance
where only the ns_writer pointer was used to check if the filesystem is
read-only.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: hda: fix potential memleak in 'add_widget_node'
As 'kobject_add' may allocated memory for 'kobject->name' when return error.
And in this function, if call 'kobject_add' failed didn't free kobject.
So call 'kobject_put' to recycling resources.
In the Linux kernel, the following vulnerability has been resolved:
mISDN: fix possible memory leak in mISDN_dsp_element_register()
Afer commit 1fa5ae857bb1 ("driver core: get rid of struct device's
bus_id string array"), the name of device is allocated dynamically,
use put_device() to give up the reference, so that the name can be
freed in kobject_cleanup() when the refcount is 0.
The 'entry' is going to be freed in mISDN_dsp_dev_release(), so the
kfree() is removed. list_del() is called in mISDN_dsp_dev_release(),
so it need be initialized.
In the Linux kernel, the following vulnerability has been resolved:
ata: libata-transport: fix error handling in ata_tdev_add()
In ata_tdev_add(), the return value of transport_add_device() is
not checked. As a result, it causes null-ptr-deref while removing
the module, because transport_remove_device() is called to remove
the device that was not added.
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
CPU: 13 PID: 13603 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #36
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : device_del+0x48/0x3a0
lr : device_del+0x44/0x3a0
Call trace:
device_del+0x48/0x3a0
attribute_container_class_device_del+0x28/0x40
transport_remove_classdev+0x60/0x7c
attribute_container_device_trigger+0x118/0x120
transport_remove_device+0x20/0x30
ata_tdev_delete+0x24/0x50 [libata]
ata_tlink_delete+0x40/0xa0 [libata]
ata_tport_delete+0x2c/0x60 [libata]
ata_port_detach+0x148/0x1b0 [libata]
ata_pci_remove_one+0x50/0x80 [libata]
ahci_remove_one+0x4c/0x8c [ahci]
Fix this by checking and handling return value of transport_add_device()
in ata_tdev_add(). In the error path, device_del() is called to delete
the device which was added earlier in this function, and ata_tdev_free()
is called to free ata_dev.
In the Linux kernel, the following vulnerability has been resolved:
ata: libata-transport: fix error handling in ata_tlink_add()
In ata_tlink_add(), the return value of transport_add_device() is
not checked. As a result, it causes null-ptr-deref while removing
the module, because transport_remove_device() is called to remove
the device that was not added.
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
CPU: 33 PID: 13850 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #12
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : device_del+0x48/0x39c
lr : device_del+0x44/0x39c
Call trace:
device_del+0x48/0x39c
attribute_container_class_device_del+0x28/0x40
transport_remove_classdev+0x60/0x7c
attribute_container_device_trigger+0x118/0x120
transport_remove_device+0x20/0x30
ata_tlink_delete+0x88/0xb0 [libata]
ata_tport_delete+0x2c/0x60 [libata]
ata_port_detach+0x148/0x1b0 [libata]
ata_pci_remove_one+0x50/0x80 [libata]
ahci_remove_one+0x4c/0x8c [ahci]
Fix this by checking and handling return value of transport_add_device()
in ata_tlink_add().
In the Linux kernel, the following vulnerability has been resolved:
ata: libata-transport: fix error handling in ata_tport_add()
In ata_tport_add(), the return value of transport_add_device() is
not checked. As a result, it causes null-ptr-deref while removing
the module, because transport_remove_device() is called to remove
the device that was not added.
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
CPU: 12 PID: 13605 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #8
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : device_del+0x48/0x39c
lr : device_del+0x44/0x39c
Call trace:
device_del+0x48/0x39c
attribute_container_class_device_del+0x28/0x40
transport_remove_classdev+0x60/0x7c
attribute_container_device_trigger+0x118/0x120
transport_remove_device+0x20/0x30
ata_tport_delete+0x34/0x60 [libata]
ata_port_detach+0x148/0x1b0 [libata]
ata_pci_remove_one+0x50/0x80 [libata]
ahci_remove_one+0x4c/0x8c [ahci]
Fix this by checking and handling return value of transport_add_device()
in ata_tport_add().
In the Linux kernel, the following vulnerability has been resolved:
net/x25: Fix skb leak in x25_lapb_receive_frame()
x25_lapb_receive_frame() using skb_copy() to get a private copy of
skb, the new skb should be freed in the undersized/fragmented skb
error handling path. Otherwise there is a memory leak.