In the Linux kernel, the following vulnerability has been resolved:
drm/msm: Make .remove and .shutdown HW shutdown consistent
Drivers' .remove and .shutdown callbacks are executed on different code
paths. The former is called when a device is removed from the bus, while
the latter is called at system shutdown time to quiesce the device.
This means that some overlap exists between the two, because both have to
take care of properly shutting down the hardware. But currently the logic
used in these two callbacks isn't consistent in msm drivers, which could
lead to kernel panic.
For example, on .remove the component is deleted and its .unbind callback
leads to the hardware being shutdown but only if the DRM device has been
marked as registered.
That check doesn't exist in the .shutdown logic and this can lead to the
driver calling drm_atomic_helper_shutdown() for a DRM device that hasn't
been properly initialized.
A situation like this can happen if drivers for expected sub-devices fail
to probe, since the .bind callback will never be executed. If that is the
case, drm_atomic_helper_shutdown() will attempt to take mutexes that are
only initialized if drm_mode_config_init() is called during a device bind.
This bug was attempted to be fixed in commit 623f279c7781 ("drm/msm: fix
shutdown hook in case GPU components failed to bind"), but unfortunately
it still happens in some cases as the one mentioned above, i.e:
systemd-shutdown[1]: Powering off.
kvm: exiting hardware virtualization
platform wifi-firmware.0: Removing from iommu group 12
platform video-firmware.0: Removing from iommu group 10
------------[ cut here ]------------
WARNING: CPU: 6 PID: 1 at drivers/gpu/drm/drm_modeset_lock.c:317 drm_modeset_lock_all_ctx+0x3c4/0x3d0
...
Hardware name: Google CoachZ (rev3+) (DT)
pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drm_modeset_lock_all_ctx+0x3c4/0x3d0
lr : drm_modeset_lock_all_ctx+0x48/0x3d0
sp : ffff80000805bb80
x29: ffff80000805bb80 x28: ffff327c00128000 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000001 x24: ffffc95d820ec030
x23: ffff327c00bbd090 x22: ffffc95d8215eca0 x21: ffff327c039c5800
x20: ffff327c039c5988 x19: ffff80000805bbe8 x18: 0000000000000034
x17: 000000040044ffff x16: ffffc95d80cac920 x15: 0000000000000000
x14: 0000000000000315 x13: 0000000000000315 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff80000805bc28 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : ffff327c00128000 x1 : 0000000000000000 x0 : ffff327c039c59b0
Call trace:
drm_modeset_lock_all_ctx+0x3c4/0x3d0
drm_atomic_helper_shutdown+0x70/0x134
msm_drv_shutdown+0x30/0x40
platform_shutdown+0x28/0x40
device_shutdown+0x148/0x350
kernel_power_off+0x38/0x80
__do_sys_reboot+0x288/0x2c0
__arm64_sys_reboot+0x28/0x34
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0x44/0xec
do_el0_svc+0x2c/0xc0
el0_svc+0x2c/0x84
el0t_64_sync_handler+0x11c/0x150
el0t_64_sync+0x18c/0x190
---[ end trace 0000000000000000 ]---
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
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
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000010eab1000
[0000000000000018] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
...
Hardware name: Google CoachZ (rev3+) (DT)
pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ww_mutex_lock+0x28/0x32c
lr : drm_modeset_lock_all_ctx+0x1b0/0x3d0
sp : ffff80000805bb50
x29: ffff80000805bb50 x28: ffff327c00128000 x27: 0000000000000000
x26: 00000
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
iommu/mediatek: Fix crash on isr after kexec()
If the system is rebooted via isr(), the IRQ handler might
be triggered before the domain is initialized. Resulting on
an invalid memory access error.
Fix:
[ 0.500930] Unable to handle kernel read from unreadable memory at virtual address 0000000000000070
[ 0.501166] Call trace:
[ 0.501174] report_iommu_fault+0x28/0xfc
[ 0.501180] mtk_iommu_isr+0x10c/0x1c0
[ joro: Fixed spelling in commit message ]
In the Linux kernel, the following vulnerability has been resolved:
btrfs: abort transaction on unexpected eb generation at btrfs_copy_root()
If we find an unexpected generation for the extent buffer we are cloning
at btrfs_copy_root(), we just WARN_ON() and don't error out and abort the
transaction, meaning we allow to persist metadata with an unexpected
generation. Instead of warning only, abort the transaction and return
-EUCLEAN.
In the Linux kernel, the following vulnerability has been resolved:
usb: dwc3: Remove WARN_ON for device endpoint command timeouts
This commit addresses a rarely observed endpoint command timeout
which causes kernel panic due to warn when 'panic_on_warn' is enabled
and unnecessary call trace prints when 'panic_on_warn' is disabled.
It is seen during fast software-controlled connect/disconnect testcases.
The following is one such endpoint command timeout that we observed:
1. Connect
=======
->dwc3_thread_interrupt
->dwc3_ep0_interrupt
->configfs_composite_setup
->composite_setup
->usb_ep_queue
->dwc3_gadget_ep0_queue
->__dwc3_gadget_ep0_queue
->__dwc3_ep0_do_control_data
->dwc3_send_gadget_ep_cmd
2. Disconnect
==========
->dwc3_thread_interrupt
->dwc3_gadget_disconnect_interrupt
->dwc3_ep0_reset_state
->dwc3_ep0_end_control_data
->dwc3_send_gadget_ep_cmd
In the issue scenario, in Exynos platforms, we observed that control
transfers for the previous connect have not yet been completed and end
transfer command sent as a part of the disconnect sequence and
processing of USB_ENDPOINT_HALT feature request from the host timeout.
This maybe an expected scenario since the controller is processing EP
commands sent as a part of the previous connect. It maybe better to
remove WARN_ON in all places where device endpoint commands are sent to
avoid unnecessary kernel panic due to warn.
In the Linux kernel, the following vulnerability has been resolved:
xfrm: Duplicate SPI Handling
The issue originates when Strongswan initiates an XFRM_MSG_ALLOCSPI
Netlink message, which triggers the kernel function xfrm_alloc_spi().
This function is expected to ensure uniqueness of the Security Parameter
Index (SPI) for inbound Security Associations (SAs). However, it can
return success even when the requested SPI is already in use, leading
to duplicate SPIs assigned to multiple inbound SAs, differentiated
only by their destination addresses.
This behavior causes inconsistencies during SPI lookups for inbound packets.
Since the lookup may return an arbitrary SA among those with the same SPI,
packet processing can fail, resulting in packet drops.
According to RFC 4301 section 4.4.2 , for inbound processing a unicast SA
is uniquely identified by the SPI and optionally protocol.
Reproducing the Issue Reliably:
To consistently reproduce the problem, restrict the available SPI range in
charon.conf : spi_min = 0x10000000 spi_max = 0x10000002
This limits the system to only 2 usable SPI values.
Next, create more than 2 Child SA. each using unique pair of src/dst address.
As soon as the 3rd Child SA is initiated, it will be assigned a duplicate
SPI, since the SPI pool is already exhausted.
With a narrow SPI range, the issue is consistently reproducible.
With a broader/default range, it becomes rare and unpredictable.
Current implementation:
xfrm_spi_hash() lookup function computes hash using daddr, proto, and family.
So if two SAs have the same SPI but different destination addresses, then
they will:
a. Hash into different buckets
b. Be stored in different linked lists (byspi + h)
c. Not be seen in the same hlist_for_each_entry_rcu() iteration.
As a result, the lookup will result in NULL and kernel allows that Duplicate SPI
Proposed Change:
xfrm_state_lookup_spi_proto() does a truly global search - across all states,
regardless of hash bucket and matches SPI and proto.
In the Linux kernel, the following vulnerability has been resolved:
crypto: x86/aegis - Add missing error checks
The skcipher_walk functions can allocate memory and can fail, so
checking for errors is necessary.
In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: host: Detect events pointing to unexpected TREs
When a remote device sends a completion event to the host, it contains a
pointer to the consumed TRE. The host uses this pointer to process all of
the TREs between it and the host's local copy of the ring's read pointer.
This works when processing completion for chained transactions, but can
lead to nasty results if the device sends an event for a single-element
transaction with a read pointer that is multiple elements ahead of the
host's read pointer.
For instance, if the host accesses an event ring while the device is
updating it, the pointer inside of the event might still point to an old
TRE. If the host uses the channel's xfer_cb() to directly free the buffer
pointed to by the TRE, the buffer will be double-freed.
This behavior was observed on an ep that used upstream EP stack without
'commit 6f18d174b73d ("bus: mhi: ep: Update read pointer only after buffer
is written")'. Where the device updated the events ring pointer before
updating the event contents, so it left a window where the host was able to
access the stale data the event pointed to, before the device had the
chance to update them. The usual pattern was that the host received an
event pointing to a TRE that is not immediately after the last processed
one, so it got treated as if it was a chained transaction, processing all
of the TREs in between the two read pointers.
This commit aims to harden the host by ensuring transactions where the
event points to a TRE that isn't local_rp + 1 are chained.
[mani: added stable tag and reworded commit message]
In the Linux kernel, the following vulnerability has been resolved:
parisc: Drop WARN_ON_ONCE() from flush_cache_vmap
I have observed warning to occassionally trigger.
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: fix soft lockup in br_multicast_query_expired()
When set multicast_query_interval to a large value, the local variable
'time' in br_multicast_send_query() may overflow. If the time is smaller
than jiffies, the timer will expire immediately, and then call mod_timer()
again, which creates a loop and may trigger the following soft lockup
issue.
watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]
CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)
Call Trace:
<IRQ>
__netdev_alloc_skb+0x2e/0x3a0
br_ip6_multicast_alloc_query+0x212/0x1b70
__br_multicast_send_query+0x376/0xac0
br_multicast_send_query+0x299/0x510
br_multicast_query_expired.constprop.0+0x16d/0x1b0
call_timer_fn+0x3b/0x2a0
__run_timers+0x619/0x950
run_timer_softirq+0x11c/0x220
handle_softirqs+0x18e/0x560
__irq_exit_rcu+0x158/0x1a0
sysvec_apic_timer_interrupt+0x76/0x90
</IRQ>
This issue can be reproduced with:
ip link add br0 type bridge
echo 1 > /sys/class/net/br0/bridge/multicast_querier
echo 0xffffffffffffffff >
/sys/class/net/br0/bridge/multicast_query_interval
ip link set dev br0 up
The multicast_startup_query_interval can also cause this issue. Similar to
the commit 99b40610956a ("net: bridge: mcast: add and enforce query
interval minimum"), add check for the query interval maximum to fix this
issue.
In the Linux kernel, the following vulnerability has been resolved:
net: gso: Forbid IPv6 TSO with extensions on devices with only IPV6_CSUM
When performing Generic Segmentation Offload (GSO) on an IPv6 packet that
contains extension headers, the kernel incorrectly requests checksum offload
if the egress device only advertises NETIF_F_IPV6_CSUM feature, which has
a strict contract: it supports checksum offload only for plain TCP or UDP
over IPv6 and explicitly does not support packets with extension headers.
The current GSO logic violates this contract by failing to disable the feature
for packets with extension headers, such as those used in GREoIPv6 tunnels.
This violation results in the device being asked to perform an operation
it cannot support, leading to a `skb_warn_bad_offload` warning and a collapse
of network throughput. While device TSO/USO is correctly bypassed in favor
of software GSO for these packets, the GSO stack must be explicitly told not
to request checksum offload.
Mask NETIF_F_IPV6_CSUM, NETIF_F_TSO6 and NETIF_F_GSO_UDP_L4
in gso_features_check if the IPv6 header contains extension headers to compute
checksum in software.
The exception is a BIG TCP extension, which, as stated in commit
68e068cabd2c6c53 ("net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets"):
"The feature is only enabled on devices that support BIG TCP TSO.
The header is only present for PF_PACKET taps like tcpdump,
and not transmitted by physical devices."
kernel log output (truncated):
WARNING: CPU: 1 PID: 5273 at net/core/dev.c:3535 skb_warn_bad_offload+0x81/0x140
...
Call Trace:
<TASK>
skb_checksum_help+0x12a/0x1f0
validate_xmit_skb+0x1a3/0x2d0
validate_xmit_skb_list+0x4f/0x80
sch_direct_xmit+0x1a2/0x380
__dev_xmit_skb+0x242/0x670
__dev_queue_xmit+0x3fc/0x7f0
ip6_finish_output2+0x25e/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_tnl_xmit+0x608/0xc00 [ip6_tunnel]
ip6gre_tunnel_xmit+0x1c0/0x390 [ip6_gre]
dev_hard_start_xmit+0x63/0x1c0
__dev_queue_xmit+0x6d0/0x7f0
ip6_finish_output2+0x214/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
inet6_csk_xmit+0xeb/0x150
__tcp_transmit_skb+0x555/0xa80
tcp_write_xmit+0x32a/0xe90
tcp_sendmsg_locked+0x437/0x1110
tcp_sendmsg+0x2f/0x50
...
skb linear: 00000000: e4 3d 1a 7d ec 30 e4 3d 1a 7e 5d 90 86 dd 60 0e
skb linear: 00000010: 00 0a 1b 34 3c 40 20 11 00 00 00 00 00 00 00 00
skb linear: 00000020: 00 00 00 00 00 12 20 11 00 00 00 00 00 00 00 00
skb linear: 00000030: 00 00 00 00 00 11 2f 00 04 01 04 01 01 00 00 00
skb linear: 00000040: 86 dd 60 0e 00 0a 1b 00 06 40 20 23 00 00 00 00
skb linear: 00000050: 00 00 00 00 00 00 00 00 00 12 20 23 00 00 00 00
skb linear: 00000060: 00 00 00 00 00 00 00 00 00 11 bf 96 14 51 13 f9
skb linear: 00000070: ae 27 a0 a8 2b e3 80 18 00 40 5b 6f 00 00 01 01
skb linear: 00000080: 08 0a 42 d4 50 d5 4b 70 f8 1a