In the Linux kernel, the following vulnerability has been resolved:
usb-storage: alauda: Check whether the media is initialized
The member "uzonesize" of struct alauda_info will remain 0
if alauda_init_media() fails, potentially causing divide errors
in alauda_read_data() and alauda_write_lba().
- Add a member "media_initialized" to struct alauda_info.
- Change a condition in alauda_check_media() to ensure the
first initialization.
- Add an error check for the return value of alauda_init_media().
In the Linux kernel, the following vulnerability has been resolved:
nfc: fix segfault in nfc_genl_dump_devices_done
When kmalloc in nfc_genl_dump_devices() fails then
nfc_genl_dump_devices_done() segfaults as below
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 25 Comm: kworker/0:1 Not tainted 5.16.0-rc4-01180-g2a987e65025e-dirty #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-6.fc35 04/01/2014
Workqueue: events netlink_sock_destruct_work
RIP: 0010:klist_iter_exit+0x26/0x80
Call Trace:
<TASK>
class_dev_iter_exit+0x15/0x20
nfc_genl_dump_devices_done+0x3b/0x50
genl_lock_done+0x84/0xd0
netlink_sock_destruct+0x8f/0x270
__sk_destruct+0x64/0x3b0
sk_destruct+0xa8/0xd0
__sk_free+0x2e8/0x3d0
sk_free+0x51/0x90
netlink_sock_destruct_work+0x1c/0x20
process_one_work+0x411/0x710
worker_thread+0x6fd/0xa80
In the Linux kernel, the following vulnerability has been resolved:
btrfs: use latest_dev in btrfs_show_devname
The test case btrfs/238 reports the warning below:
WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs]
CPU: 2 PID: 1 Comm: systemd Tainted: G W O 5.14.0-rc1-custom #72
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
btrfs_show_devname+0x108/0x1b4 [btrfs]
show_mountinfo+0x234/0x2c4
m_show+0x28/0x34
seq_read_iter+0x12c/0x3c4
vfs_read+0x29c/0x2c8
ksys_read+0x80/0xec
__arm64_sys_read+0x28/0x34
invoke_syscall+0x50/0xf8
do_el0_svc+0x88/0x138
el0_svc+0x2c/0x8c
el0t_64_sync_handler+0x84/0xe4
el0t_64_sync+0x198/0x19c
Reason:
While btrfs_prepare_sprout() moves the fs_devices::devices into
fs_devices::seed_list, the btrfs_show_devname() searches for the devices
and found none, leading to the warning as in above.
Fix:
latest_dev is updated according to the changes to the device list.
That means we could use the latest_dev->name to show the device name in
/proc/self/mounts, the pointer will be always valid as it's assigned
before the device is deleted from the list in remove or replace.
The RCU protection is sufficient as the device structure is freed after
synchronization.
In the Linux kernel, the following vulnerability has been resolved:
dm btree remove: fix use after free in rebalance_children()
Move dm_tm_unlock() after dm_tm_dec().
In the Linux kernel, the following vulnerability has been resolved:
igbvf: fix double free in `igbvf_probe`
In `igbvf_probe`, if register_netdev() fails, the program will go to
label err_hw_init, and then to label err_ioremap. In free_netdev() which
is just below label err_ioremap, there is `list_for_each_entry_safe` and
`netif_napi_del` which aims to delete all entries in `dev->napi_list`.
The program has added an entry `adapter->rx_ring->napi` which is added by
`netif_napi_add` in igbvf_alloc_queues(). However, adapter->rx_ring has
been freed below label err_hw_init. So this a UAF.
In terms of how to patch the problem, we can refer to igbvf_remove() and
delete the entry before `adapter->rx_ring`.
The KASAN logs are as follows:
[ 35.126075] BUG: KASAN: use-after-free in free_netdev+0x1fd/0x450
[ 35.127170] Read of size 8 at addr ffff88810126d990 by task modprobe/366
[ 35.128360]
[ 35.128643] CPU: 1 PID: 366 Comm: modprobe Not tainted 5.15.0-rc2+ #14
[ 35.129789] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[ 35.131749] Call Trace:
[ 35.132199] dump_stack_lvl+0x59/0x7b
[ 35.132865] print_address_description+0x7c/0x3b0
[ 35.133707] ? free_netdev+0x1fd/0x450
[ 35.134378] __kasan_report+0x160/0x1c0
[ 35.135063] ? free_netdev+0x1fd/0x450
[ 35.135738] kasan_report+0x4b/0x70
[ 35.136367] free_netdev+0x1fd/0x450
[ 35.137006] igbvf_probe+0x121d/0x1a10 [igbvf]
[ 35.137808] ? igbvf_vlan_rx_add_vid+0x100/0x100 [igbvf]
[ 35.138751] local_pci_probe+0x13c/0x1f0
[ 35.139461] pci_device_probe+0x37e/0x6c0
[ 35.165526]
[ 35.165806] Allocated by task 366:
[ 35.166414] ____kasan_kmalloc+0xc4/0xf0
[ 35.167117] foo_kmem_cache_alloc_trace+0x3c/0x50 [igbvf]
[ 35.168078] igbvf_probe+0x9c5/0x1a10 [igbvf]
[ 35.168866] local_pci_probe+0x13c/0x1f0
[ 35.169565] pci_device_probe+0x37e/0x6c0
[ 35.179713]
[ 35.179993] Freed by task 366:
[ 35.180539] kasan_set_track+0x4c/0x80
[ 35.181211] kasan_set_free_info+0x1f/0x40
[ 35.181942] ____kasan_slab_free+0x103/0x140
[ 35.182703] kfree+0xe3/0x250
[ 35.183239] igbvf_probe+0x1173/0x1a10 [igbvf]
[ 35.184040] local_pci_probe+0x13c/0x1f0
In the Linux kernel, the following vulnerability has been resolved:
io-wq: check for wq exit after adding new worker task_work
We check IO_WQ_BIT_EXIT before attempting to create a new worker, and
wq exit cancels pending work if we have any. But it's possible to have
a race between the two, where creation checks exit finding it not set,
but we're in the process of exiting. The exit side will cancel pending
creation task_work, but there's a gap where we add task_work after we've
canceled existing creations at exit time.
Fix this by checking the EXIT bit post adding the creation task_work.
If it's set, run the same cancelation that exit does.