In the Linux kernel, the following vulnerability has been resolved:
codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()
After making all ->qlen_notify() callbacks idempotent, now it is safe to
remove the check of qlen!=0 from both fq_codel_dequeue() and
codel_qdisc_dequeue().
In the Linux kernel, the following vulnerability has been resolved:
wifi: at76c50x: fix use after free access in at76_disconnect
The memory pointed to by priv is freed at the end of at76_delete_device
function (using ieee80211_free_hw). But the code then accesses the udev
field of the freed object to put the USB device. This may also lead to a
memory leak of the usb device. Fix this by using udev from interface.
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered
Russell King reports that a system with mv88e6xxx dereferences a NULL
pointer when unbinding this driver:
https://lore.kernel.org/netdev/Z_lRkMlTJ1KQ0kVX@shell.armlinux.org.uk/
The crash seems to be in devlink_region_destroy(), which is not NULL
tolerant but is given a NULL devlink global region pointer.
At least on some chips, some devlink regions are conditionally registered
since the blamed commit, see mv88e6xxx_setup_devlink_regions_global():
if (cond && !cond(chip))
continue;
These are MV88E6XXX_REGION_STU and MV88E6XXX_REGION_PVT. If the chip
does not have an STU or PVT, it should crash like this.
To fix the issue, avoid unregistering those regions which are NULL, i.e.
were skipped at mv88e6xxx_setup_devlink_regions_global() time.
In the Linux kernel, the following vulnerability has been resolved:
cxgb4: fix memory leak in cxgb4_init_ethtool_filters() error path
In the for loop used to allocate the loc_array and bmap for each port, a
memory leak is possible when the allocation for loc_array succeeds,
but the allocation for bmap fails. This is because when the control flow
goes to the label free_eth_finfo, only the allocations starting from
(i-1)th iteration are freed.
Fix that by freeing the loc_array in the bmap allocation error path.
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix nested key length validation in the set() action
It's not safe to access nla_len(ovs_key) if the data is smaller than
the netlink header. Check that the attribute is OK first.
In the Linux kernel, the following vulnerability has been resolved:
net: mctp: Set SOCK_RCU_FREE
Bind lookup runs under RCU, so ensure that a socket doesn't go away in
the middle of a lookup.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btrtl: Prevent potential NULL dereference
The btrtl_initialize() function checks that rtl_load_file() either
had an error or it loaded a zero length file. However, if it loaded
a zero length file then the error code is not set correctly. It
results in an error pointer vs NULL bug, followed by a NULL pointer
dereference. This was detected by Smatch:
drivers/bluetooth/btrtl.c:592 btrtl_initialize() warn: passing zero to 'ERR_PTR'
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Purge vif txq in ieee80211_do_stop()
After ieee80211_do_stop() SKB from vif's txq could still be processed.
Indeed another concurrent vif schedule_and_wake_txq call could cause
those packets to be dequeued (see ieee80211_handle_wake_tx_queue())
without checking the sdata current state.
Because vif.drv_priv is now cleared in this function, this could lead to
driver crash.
For example in ath12k, ahvif is store in vif.drv_priv. Thus if
ath12k_mac_op_tx() is called after ieee80211_do_stop(), ahvif->ah can be
NULL, leading the ath12k_warn(ahvif->ah,...) call in this function to
trigger the NULL deref below.
Unable to handle kernel paging request at virtual address dfffffc000000001
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
batman_adv: bat0: Interface deactivated: brbh1337
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
[dfffffc000000001] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] SMP
CPU: 1 UID: 0 PID: 978 Comm: lbd Not tainted 6.13.0-g633f875b8f1e #114
Hardware name: HW (DT)
pstate: 10000005 (nzcV daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ath12k_mac_op_tx+0x6cc/0x29b8 [ath12k]
lr : ath12k_mac_op_tx+0x174/0x29b8 [ath12k]
sp : ffffffc086ace450
x29: ffffffc086ace450 x28: 0000000000000000 x27: 1ffffff810d59ca4
x26: ffffff801d05f7c0 x25: 0000000000000000 x24: 000000004000001e
x23: ffffff8009ce4926 x22: ffffff801f9c0800 x21: ffffff801d05f7f0
x20: ffffff8034a19f40 x19: 0000000000000000 x18: ffffff801f9c0958
x17: ffffff800bc0a504 x16: dfffffc000000000 x15: ffffffc086ace4f8
x14: ffffff801d05f83c x13: 0000000000000000 x12: ffffffb003a0bf03
x11: 0000000000000000 x10: ffffffb003a0bf02 x9 : ffffff8034a19f40
x8 : ffffff801d05f818 x7 : 1ffffff0069433dc x6 : ffffff8034a19ee0
x5 : ffffff801d05f7f0 x4 : 0000000000000000 x3 : 0000000000000001
x2 : 0000000000000000 x1 : dfffffc000000000 x0 : 0000000000000008
Call trace:
ath12k_mac_op_tx+0x6cc/0x29b8 [ath12k] (P)
ieee80211_handle_wake_tx_queue+0x16c/0x260
ieee80211_queue_skb+0xeec/0x1d20
ieee80211_tx+0x200/0x2c8
ieee80211_xmit+0x22c/0x338
__ieee80211_subif_start_xmit+0x7e8/0xc60
ieee80211_subif_start_xmit+0xc4/0xee0
__ieee80211_subif_start_xmit_8023.isra.0+0x854/0x17a0
ieee80211_subif_start_xmit_8023+0x124/0x488
dev_hard_start_xmit+0x160/0x5a8
__dev_queue_xmit+0x6f8/0x3120
br_dev_queue_push_xmit+0x120/0x4a8
__br_forward+0xe4/0x2b0
deliver_clone+0x5c/0xd0
br_flood+0x398/0x580
br_dev_xmit+0x454/0x9f8
dev_hard_start_xmit+0x160/0x5a8
__dev_queue_xmit+0x6f8/0x3120
ip6_finish_output2+0xc28/0x1b60
__ip6_finish_output+0x38c/0x638
ip6_output+0x1b4/0x338
ip6_local_out+0x7c/0xa8
ip6_send_skb+0x7c/0x1b0
ip6_push_pending_frames+0x94/0xd0
rawv6_sendmsg+0x1a98/0x2898
inet_sendmsg+0x94/0xe0
__sys_sendto+0x1e4/0x308
__arm64_sys_sendto+0xc4/0x140
do_el0_svc+0x110/0x280
el0_svc+0x20/0x60
el0t_64_sync_handler+0x104/0x138
el0t_64_sync+0x154/0x158
To avoid that, empty vif's txq at ieee80211_do_stop() so no packet could
be dequeued after ieee80211_do_stop() (new packets cannot be queued
because SDATA_STATE_RUNNING is cleared at this point).
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: free routing table on probe failure
If complete = true in dsa_tree_setup(), it means that we are the last
switch of the tree which is successfully probing, and we should be
setting up all switches from our probe path.
After "complete" becomes true, dsa_tree_setup_cpu_ports() or any
subsequent function may fail. If that happens, the entire tree setup is
in limbo: the first N-1 switches have successfully finished probing
(doing nothing but having allocated persistent memory in the tree's
dst->ports, and maybe dst->rtable), and switch N failed to probe, ending
the tree setup process before anything is tangible from the user's PoV.
If switch N fails to probe, its memory (ports) will be freed and removed
from dst->ports. However, the dst->rtable elements pointing to its ports,
as created by dsa_link_touch(), will remain there, and will lead to
use-after-free if dereferenced.
If dsa_tree_setup_switches() returns -EPROBE_DEFER, which is entirely
possible because that is where ds->ops->setup() is, we get a kasan
report like this:
==================================================================
BUG: KASAN: slab-use-after-free in mv88e6xxx_setup_upstream_port+0x240/0x568
Read of size 8 at addr ffff000004f56020 by task kworker/u8:3/42
Call trace:
__asan_report_load8_noabort+0x20/0x30
mv88e6xxx_setup_upstream_port+0x240/0x568
mv88e6xxx_setup+0xebc/0x1eb0
dsa_register_switch+0x1af4/0x2ae0
mv88e6xxx_register_switch+0x1b8/0x2a8
mv88e6xxx_probe+0xc4c/0xf60
mdio_probe+0x78/0xb8
really_probe+0x2b8/0x5a8
__driver_probe_device+0x164/0x298
driver_probe_device+0x78/0x258
__device_attach_driver+0x274/0x350
Allocated by task 42:
__kasan_kmalloc+0x84/0xa0
__kmalloc_cache_noprof+0x298/0x490
dsa_switch_touch_ports+0x174/0x3d8
dsa_register_switch+0x800/0x2ae0
mv88e6xxx_register_switch+0x1b8/0x2a8
mv88e6xxx_probe+0xc4c/0xf60
mdio_probe+0x78/0xb8
really_probe+0x2b8/0x5a8
__driver_probe_device+0x164/0x298
driver_probe_device+0x78/0x258
__device_attach_driver+0x274/0x350
Freed by task 42:
__kasan_slab_free+0x48/0x68
kfree+0x138/0x418
dsa_register_switch+0x2694/0x2ae0
mv88e6xxx_register_switch+0x1b8/0x2a8
mv88e6xxx_probe+0xc4c/0xf60
mdio_probe+0x78/0xb8
really_probe+0x2b8/0x5a8
__driver_probe_device+0x164/0x298
driver_probe_device+0x78/0x258
__device_attach_driver+0x274/0x350
The simplest way to fix the bug is to delete the routing table in its
entirety. dsa_tree_setup_routing_table() has no problem in regenerating
it even if we deleted links between ports other than those of switch N,
because dsa_link_touch() first checks whether the port pair already
exists in dst->rtable, allocating if not.
The deletion of the routing table in its entirety already exists in
dsa_tree_teardown(), so refactor that into a function that can also be
called from the tree setup error path.
In my analysis of the commit to blame, it is the one which added
dsa_link elements to dst->rtable. Prior to that, each switch had its own
ds->rtable which is freed when the switch fails to probe. But the tree
is potentially persistent memory.