In the Linux kernel, the following vulnerability has been resolved:
iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()
When performing an iSCSI boot using IPv6, iscsistart still reads the
/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix
length is 64, this causes the shift exponent to become negative,
triggering a UBSAN warning. As the concept of a subnet mask does not
apply to IPv6, the value is set to ~0 to suppress the warning message.
In the Linux kernel, the following vulnerability has been resolved:
net_sched: Prevent creation of classes with TC_H_ROOT
The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination
condition when traversing up the qdisc tree to update parent backlog
counters. However, if a class is created with classid TC_H_ROOT, the
traversal terminates prematurely at this class instead of reaching the
actual root qdisc, causing parent statistics to be incorrectly maintained.
In case of DRR, this could lead to a crash as reported by Mingi Cho.
Prevent the creation of any Qdisc class with classid TC_H_ROOT
(0xFFFFFFFF) across all qdisc types, as suggested by Jamal.
In the Linux kernel, the following vulnerability has been resolved:
fbdev: hyperv_fb: Allow graceful removal of framebuffer
When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to
release the framebuffer forcefully. If this framebuffer is in use it
produce the following WARN and hence this framebuffer is never released.
[ 44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40
< snip >
[ 44.111289] Call Trace:
[ 44.111290] <TASK>
[ 44.111291] ? show_regs+0x6c/0x80
[ 44.111295] ? __warn+0x8d/0x150
[ 44.111298] ? framebuffer_release+0x2c/0x40
[ 44.111300] ? report_bug+0x182/0x1b0
[ 44.111303] ? handle_bug+0x6e/0xb0
[ 44.111306] ? exc_invalid_op+0x18/0x80
[ 44.111308] ? asm_exc_invalid_op+0x1b/0x20
[ 44.111311] ? framebuffer_release+0x2c/0x40
[ 44.111313] ? hvfb_remove+0x86/0xa0 [hyperv_fb]
[ 44.111315] vmbus_remove+0x24/0x40 [hv_vmbus]
[ 44.111323] device_remove+0x40/0x80
[ 44.111325] device_release_driver_internal+0x20b/0x270
[ 44.111327] ? bus_find_device+0xb3/0xf0
Fix this by moving the release of framebuffer and assosiated memory
to fb_ops.fb_destroy function, so that framebuffer framework handles
it gracefully.
While we fix this, also replace manual registrations/unregistration of
framebuffer with devm_register_framebuffer.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla1280: Fix kernel oops when debug level > 2
A null dereference or oops exception will eventually occur when qla1280.c
driver is compiled with DEBUG_QLA1280 enabled and ql_debug_level > 2. I
think its clear from the code that the intention here is sg_dma_len(s) not
length of sg_next(s) when printing the debug info.
In the Linux kernel, the following vulnerability has been resolved:
HID: appleir: Fix potential NULL dereference at raw event handle
Syzkaller reports a NULL pointer dereference issue in input_event().
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: null-ptr-deref in is_event_supported drivers/input/input.c:67 [inline]
BUG: KASAN: null-ptr-deref in input_event+0x42/0xa0 drivers/input/input.c:395
Read of size 8 at addr 0000000000000028 by task syz-executor199/2949
CPU: 0 UID: 0 PID: 2949 Comm: syz-executor199 Not tainted 6.13.0-rc4-syzkaller-00076-gf097a36ef88d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
kasan_report+0xd9/0x110 mm/kasan/report.c:602
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
is_event_supported drivers/input/input.c:67 [inline]
input_event+0x42/0xa0 drivers/input/input.c:395
input_report_key include/linux/input.h:439 [inline]
key_down drivers/hid/hid-appleir.c:159 [inline]
appleir_raw_event+0x3e5/0x5e0 drivers/hid/hid-appleir.c:232
__hid_input_report.constprop.0+0x312/0x440 drivers/hid/hid-core.c:2111
hid_ctrl+0x49f/0x550 drivers/hid/usbhid/hid-core.c:484
__usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734
dummy_timer+0x17f7/0x3960 drivers/usb/gadget/udc/dummy_hcd.c:1993
__run_hrtimer kernel/time/hrtimer.c:1739 [inline]
__hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1820
handle_softirqs+0x206/0x8d0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0xfa/0x160 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__mod_timer+0x8f6/0xdc0 kernel/time/timer.c:1185
add_timer+0x62/0x90 kernel/time/timer.c:1295
schedule_timeout+0x11f/0x280 kernel/time/sleep_timeout.c:98
usbhid_wait_io+0x1c7/0x380 drivers/hid/usbhid/hid-core.c:645
usbhid_init_reports+0x19f/0x390 drivers/hid/usbhid/hid-core.c:784
hiddev_ioctl+0x1133/0x15b0 drivers/hid/usbhid/hiddev.c:794
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
This happens due to the malformed report items sent by the emulated device
which results in a report, that has no fields, being added to the report list.
Due to this appleir_input_configured() is never called, hidinput_connect()
fails which results in the HID_CLAIMED_INPUT flag is not being set. However,
it does not make appleir_probe() fail and lets the event callback to be
called without the associated input device.
Thus, add a check for the HID_CLAIMED_INPUT flag and leave the event hook
early if the driver didn't claim any input_dev for some reason. Moreover,
some other hid drivers accessing input_dev in their event callbacks do have
similar checks, too.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
llc: do not use skb_get() before dev_queue_xmit()
syzbot is able to crash hosts [1], using llc and devices
not supporting IFF_TX_SKB_SHARING.
In this case, e1000 driver calls eth_skb_pad(), while
the skb is shared.
Simply replace skb_get() by skb_clone() in net/llc/llc_s_ac.c
Note that e1000 driver might have an issue with pktgen,
because it does not clear IFF_TX_SKB_SHARING, this is an
orthogonal change.
We need to audit other skb_get() uses in net/llc.
[1]
kernel BUG at net/core/skbuff.c:2178 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 16371 Comm: syz.2.2764 Not tainted 6.14.0-rc4-syzkaller-00052-gac9c34d1e45a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pskb_expand_head+0x6ce/0x1240 net/core/skbuff.c:2178
Call Trace:
<TASK>
__skb_pad+0x18a/0x610 net/core/skbuff.c:2466
__skb_put_padto include/linux/skbuff.h:3843 [inline]
skb_put_padto include/linux/skbuff.h:3862 [inline]
eth_skb_pad include/linux/etherdevice.h:656 [inline]
e1000_xmit_frame+0x2d99/0x5800 drivers/net/ethernet/intel/e1000/e1000_main.c:3128
__netdev_start_xmit include/linux/netdevice.h:5151 [inline]
netdev_start_xmit include/linux/netdevice.h:5160 [inline]
xmit_one net/core/dev.c:3806 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3822
sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343
__dev_xmit_skb net/core/dev.c:4045 [inline]
__dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4621
dev_queue_xmit include/linux/netdevice.h:3313 [inline]
llc_sap_action_send_test_c+0x268/0x320 net/llc/llc_s_ac.c:144
llc_exec_sap_trans_actions net/llc/llc_sap.c:153 [inline]
llc_sap_next_state net/llc/llc_sap.c:182 [inline]
llc_sap_state_process+0x239/0x510 net/llc/llc_sap.c:209
llc_ui_sendmsg+0xd0d/0x14e0 net/llc/af_llc.c:993
sock_sendmsg_nosec net/socket.c:718 [inline]
In the Linux kernel, the following vulnerability has been resolved:
usb: renesas_usbhs: Flush the notify_hotplug_work
When performing continuous unbind/bind operations on the USB drivers
available on the Renesas RZ/G2L SoC, a kernel crash with the message
"Unable to handle kernel NULL pointer dereference at virtual address"
may occur. This issue points to the usbhsc_notify_hotplug() function.
Flush the delayed work to avoid its execution when driver resources are
unavailable.
In the Linux kernel, the following vulnerability has been resolved:
vlan: enforce underlying device type
Currently, VLAN devices can be created on top of non-ethernet devices.
Besides the fact that it doesn't make much sense, this also causes a
bug which leaks the address of a kernel function to usermode.
When creating a VLAN device, we initialize GARP (garp_init_applicant)
and MRP (mrp_init_applicant) for the underlying device.
As part of the initialization process, we add the multicast address of
each applicant to the underlying device, by calling dev_mc_add.
__dev_mc_add uses dev->addr_len to determine the length of the new
multicast address.
This causes an out-of-bounds read if dev->addr_len is greater than 6,
since the multicast addresses provided by GARP and MRP are only 6
bytes long.
This behaviour can be reproduced using the following commands:
ip tunnel add gretest mode ip6gre local ::1 remote ::2 dev lo
ip l set up dev gretest
ip link add link gretest name vlantest type vlan id 100
Then, the following command will display the address of garp_pdu_rcv:
ip maddr show | grep 01:80:c2:00:00:21
Fix the bug by enforcing the type of the underlying device during VLAN
device initialization.
In the Linux kernel, the following vulnerability has been resolved:
ppp: Fix KMSAN uninit-value warning with bpf
Syzbot caught an "KMSAN: uninit-value" warning [1], which is caused by the
ppp driver not initializing a 2-byte header when using socket filter.
The following code can generate a PPP filter BPF program:
'''
struct bpf_program fp;
pcap_t *handle;
handle = pcap_open_dead(DLT_PPP_PPPD, 65535);
pcap_compile(handle, &fp, "ip and outbound", 0, 0);
bpf_dump(&fp, 1);
'''
Its output is:
'''
(000) ldh [2]
(001) jeq #0x21 jt 2 jf 5
(002) ldb [0]
(003) jeq #0x1 jt 4 jf 5
(004) ret #65535
(005) ret #0
'''
Wen can find similar code at the following link:
https://github.com/ppp-project/ppp/blob/master/pppd/options.c#L1680
The maintainer of this code repository is also the original maintainer
of the ppp driver.
As you can see the BPF program skips 2 bytes of data and then reads the
'Protocol' field to determine if it's an IP packet. Then it read the first
byte of the first 2 bytes to determine the direction.
The issue is that only the first byte indicating direction is initialized
in current ppp driver code while the second byte is not initialized.
For normal BPF programs generated by libpcap, uninitialized data won't be
used, so it's not a problem. However, for carefully crafted BPF programs,
such as those generated by syzkaller [2], which start reading from offset
0, the uninitialized data will be used and caught by KMSAN.
[1] https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791
[2] https://syzkaller.appspot.com/text?tag=ReproC&x=11994913980000