Security Vulnerabilities
- CVEs Published In August 2024
In the Linux kernel, the following vulnerability has been resolved:
memcg: protect concurrent access to mem_cgroup_idr
Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after
many small jobs") decoupled the memcg IDs from the CSS ID space to fix the
cgroup creation failures. It introduced IDR to maintain the memcg ID
space. The IDR depends on external synchronization mechanisms for
modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace()
happen within css callback and thus are protected through cgroup_mutex
from concurrent modifications. However idr_remove() for mem_cgroup_idr
was not protected against concurrency and can be run concurrently for
different memcgs when they hit their refcnt to zero. Fix that.
We have been seeing list_lru based kernel crashes at a low frequency in
our fleet for a long time. These crashes were in different part of
list_lru code including list_lru_add(), list_lru_del() and reparenting
code. Upon further inspection, it looked like for a given object (dentry
and inode), the super_block's list_lru didn't have list_lru_one for the
memcg of that object. The initial suspicions were either the object is
not allocated through kmem_cache_alloc_lru() or somehow
memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but
returned success. No evidence were found for these cases.
Looking more deeply, we started seeing situations where valid memcg's id
is not present in mem_cgroup_idr and in some cases multiple valid memcgs
have same id and mem_cgroup_idr is pointing to one of them. So, the most
reasonable explanation is that these situations can happen due to race
between multiple idr_remove() calls or race between
idr_alloc()/idr_replace() and idr_remove(). These races are causing
multiple memcgs to acquire the same ID and then offlining of one of them
would cleanup list_lrus on the system for all of them. Later access from
other memcgs to the list_lru cause crashes due to missing list_lru_one.
In the Linux kernel, the following vulnerability has been resolved:
serial: core: check uartclk for zero to avoid divide by zero
Calling ioctl TIOCSSERIAL with an invalid baud_base can
result in uartclk being zero, which will result in a
divide by zero error in uart_get_divisor(). The check for
uartclk being zero in uart_set_info() needs to be done
before other settings are made as subsequent calls to
ioctl TIOCSSERIAL for the same port would be impacted if
the uartclk check was done where uartclk gets set.
Oops: divide error: 0000 PREEMPT SMP KASAN PTI
RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580)
Call Trace:
<TASK>
serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576
drivers/tty/serial/8250/8250_port.c:2589)
serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502
drivers/tty/serial/8250/8250_port.c:2741)
serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862)
uart_change_line_settings (./include/linux/spinlock.h:376
./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222)
uart_port_startup (drivers/tty/serial/serial_core.c:342)
uart_startup (drivers/tty/serial/serial_core.c:368)
uart_set_info (drivers/tty/serial/serial_core.c:1034)
uart_set_info_user (drivers/tty/serial/serial_core.c:1059)
tty_set_serial (drivers/tty/tty_io.c:2637)
tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791)
__x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907
fs/ioctl.c:893 fs/ioctl.c:893)
do_syscall_64 (arch/x86/entry/common.c:52
(discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Rule: add
In the Linux kernel, the following vulnerability has been resolved:
drm/client: fix null pointer dereference in drm_client_modeset_probe
In drm_client_modeset_probe(), the return value of drm_mode_duplicate() is
assigned to modeset->mode, which will lead to a possible NULL pointer
dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: cs-amp-lib: Fix NULL pointer crash if efi.get_variable is NULL
Call efi_rt_services_supported() to check that efi.get_variable exists
before calling it.
In the Linux kernel, the following vulnerability has been resolved:
net: drop bad gso csum_start and offset in virtio_net_hdr
Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb
for GSO packets.
The function already checks that a checksum requested with
VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets
this might not hold for segs after segmentation.
Syzkaller demonstrated to reach this warning in skb_checksum_help
offset = skb_checksum_start_offset(skb);
ret = -EINVAL;
if (WARN_ON_ONCE(offset >= skb_headlen(skb)))
By injecting a TSO packet:
WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0
ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774
ip_finish_output_gso net/ipv4/ip_output.c:279 [inline]
__ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301
iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4850 [inline]
netdev_start_xmit include/linux/netdevice.h:4864 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
packet_snd net/packet/af_packet.c:3073 [inline]
The geometry of the bad input packet at tcp_gso_segment:
[ 52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0
[ 52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244
[ 52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0))
[ 52.003050][ T8403] csum(0x60000c7 start=199 offset=1536
ip_summed=3 complete_sw=0 valid=0 level=0)
Mitigate with stricter input validation.
csum_offset: for GSO packets, deduce the correct value from gso_type.
This is already done for USO. Extend it to TSO. Let UFO be:
udp[46]_ufo_fragment ignores these fields and always computes the
checksum in software.
csum_start: finding the real offset requires parsing to the transport
header. Do not add a parser, use existing segmentation parsing. Thanks
to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded.
Again test both TSO and USO. Do not test UFO for the above reason, and
do not test UDP tunnel offload.
GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be
CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit
from devices with no checksum offload"), but then still these fields
are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no
need to test for ip_summed == CHECKSUM_PARTIAL first.
This revises an existing fix mentioned in the Fixes tag, which broke
small packets with GSO offload, as detected by kselftests.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix null pointer deref in dcn20_resource.c
Fixes a hang thats triggered when MPV is run on a DCN401 dGPU:
mpv --hwdec=vaapi --vo=gpu --hwdec-codecs=all
and then enabling fullscreen playback (double click on the video)
The following calltrace will be seen:
[ 181.843989] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 181.843997] #PF: supervisor instruction fetch in kernel mode
[ 181.844003] #PF: error_code(0x0010) - not-present page
[ 181.844009] PGD 0 P4D 0
[ 181.844020] Oops: 0010 [#1] PREEMPT SMP NOPTI
[ 181.844028] CPU: 6 PID: 1892 Comm: gnome-shell Tainted: G W OE 6.5.0-41-generic #41~22.04.2-Ubuntu
[ 181.844038] Hardware name: System manufacturer System Product Name/CROSSHAIR VI HERO, BIOS 6302 10/23/2018
[ 181.844044] RIP: 0010:0x0
[ 181.844079] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[ 181.844084] RSP: 0018:ffffb593c2b8f7b0 EFLAGS: 00010246
[ 181.844093] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
[ 181.844099] RDX: ffffb593c2b8f804 RSI: ffffb593c2b8f7e0 RDI: ffff9e3c8e758400
[ 181.844105] RBP: ffffb593c2b8f7b8 R08: ffffb593c2b8f9c8 R09: ffffb593c2b8f96c
[ 181.844110] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb593c2b8f9c8
[ 181.844115] R13: 0000000000000001 R14: ffff9e3c88000000 R15: 0000000000000005
[ 181.844121] FS: 00007c6e323bb5c0(0000) GS:ffff9e3f85f80000(0000) knlGS:0000000000000000
[ 181.844128] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 181.844134] CR2: ffffffffffffffd6 CR3: 0000000140fbe000 CR4: 00000000003506e0
[ 181.844141] Call Trace:
[ 181.844146] <TASK>
[ 181.844153] ? show_regs+0x6d/0x80
[ 181.844167] ? __die+0x24/0x80
[ 181.844179] ? page_fault_oops+0x99/0x1b0
[ 181.844192] ? do_user_addr_fault+0x31d/0x6b0
[ 181.844204] ? exc_page_fault+0x83/0x1b0
[ 181.844216] ? asm_exc_page_fault+0x27/0x30
[ 181.844237] dcn20_get_dcc_compression_cap+0x23/0x30 [amdgpu]
[ 181.845115] amdgpu_dm_plane_validate_dcc.constprop.0+0xe5/0x180 [amdgpu]
[ 181.845985] amdgpu_dm_plane_fill_plane_buffer_attributes+0x300/0x580 [amdgpu]
[ 181.846848] fill_dc_plane_info_and_addr+0x258/0x350 [amdgpu]
[ 181.847734] fill_dc_plane_attributes+0x162/0x350 [amdgpu]
[ 181.848748] dm_update_plane_state.constprop.0+0x4e3/0x6b0 [amdgpu]
[ 181.849791] ? dm_update_plane_state.constprop.0+0x4e3/0x6b0 [amdgpu]
[ 181.850840] amdgpu_dm_atomic_check+0xdfe/0x1760 [amdgpu]
In the Linux kernel, the following vulnerability has been resolved:
media: xc2028: avoid use-after-free in load_firmware_cb()
syzkaller reported use-after-free in load_firmware_cb() [1].
The reason is because the module allocated a struct tuner in tuner_probe(),
and then the module initialization failed, the struct tuner was released.
A worker which created during module initialization accesses this struct
tuner later, it caused use-after-free.
The process is as follows:
task-6504 worker_thread
tuner_probe <= alloc dvb_frontend [2]
...
request_firmware_nowait <= create a worker
...
tuner_remove <= free dvb_frontend
...
request_firmware_work_func <= the firmware is ready
load_firmware_cb <= but now the dvb_frontend has been freed
To fix the issue, check the dvd_frontend in load_firmware_cb(), if it is
null, report a warning and just return.
[1]:
==================================================================
BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0
Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504
Call trace:
load_firmware_cb+0x1310/0x17a0
request_firmware_work_func+0x128/0x220
process_one_work+0x770/0x1824
worker_thread+0x488/0xea0
kthread+0x300/0x430
ret_from_fork+0x10/0x20
Allocated by task 6504:
kzalloc
tuner_probe+0xb0/0x1430
i2c_device_probe+0x92c/0xaf0
really_probe+0x678/0xcd0
driver_probe_device+0x280/0x370
__device_attach_driver+0x220/0x330
bus_for_each_drv+0x134/0x1c0
__device_attach+0x1f4/0x410
device_initial_probe+0x20/0x30
bus_probe_device+0x184/0x200
device_add+0x924/0x12c0
device_register+0x24/0x30
i2c_new_device+0x4e0/0xc44
v4l2_i2c_new_subdev_board+0xbc/0x290
v4l2_i2c_new_subdev+0xc8/0x104
em28xx_v4l2_init+0x1dd0/0x3770
Freed by task 6504:
kfree+0x238/0x4e4
tuner_remove+0x144/0x1c0
i2c_device_remove+0xc8/0x290
__device_release_driver+0x314/0x5fc
device_release_driver+0x30/0x44
bus_remove_device+0x244/0x490
device_del+0x350/0x900
device_unregister+0x28/0xd0
i2c_unregister_device+0x174/0x1d0
v4l2_device_unregister+0x224/0x380
em28xx_v4l2_init+0x1d90/0x3770
The buggy address belongs to the object at ffff8000d7ca2000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 776 bytes inside of
2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800)
The buggy address belongs to the page:
page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0
flags: 0x7ff800000000100(slab)
raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
[2]
Actually, it is allocated for struct tuner, and dvb_frontend is inside.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix NULL pointer dereference for DTN log in DCN401
When users run the command:
cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log
The following NULL pointer dereference happens:
[ +0.000003] BUG: kernel NULL pointer dereference, address: NULL
[ +0.000005] #PF: supervisor instruction fetch in kernel mode
[ +0.000002] #PF: error_code(0x0010) - not-present page
[ +0.000002] PGD 0 P4D 0
[ +0.000004] Oops: 0010 [#1] PREEMPT SMP NOPTI
[ +0.000003] RIP: 0010:0x0
[ +0.000008] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[...]
[ +0.000002] PKRU: 55555554
[ +0.000002] Call Trace:
[ +0.000002] <TASK>
[ +0.000003] ? show_regs+0x65/0x70
[ +0.000006] ? __die+0x24/0x70
[ +0.000004] ? page_fault_oops+0x160/0x470
[ +0.000006] ? do_user_addr_fault+0x2b5/0x690
[ +0.000003] ? prb_read_valid+0x1c/0x30
[ +0.000005] ? exc_page_fault+0x8c/0x1a0
[ +0.000005] ? asm_exc_page_fault+0x27/0x30
[ +0.000012] dcn10_log_color_state+0xf9/0x510 [amdgpu]
[ +0.000306] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000003] ? vsnprintf+0x2fb/0x600
[ +0.000009] dcn10_log_hw_state+0xfd0/0xfe0 [amdgpu]
[ +0.000218] ? __mod_memcg_lruvec_state+0xe8/0x170
[ +0.000008] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000002] ? debug_smp_processor_id+0x17/0x20
[ +0.000003] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000002] ? set_ptes.isra.0+0x2b/0x90
[ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000002] ? _raw_spin_unlock+0x19/0x40
[ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000002] ? do_anonymous_page+0x337/0x700
[ +0.000004] dtn_log_read+0x82/0x120 [amdgpu]
[ +0.000207] full_proxy_read+0x66/0x90
[ +0.000007] vfs_read+0xb0/0x340
[ +0.000005] ? __count_memcg_events+0x79/0xe0
[ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5
[ +0.000003] ? count_memcg_events.constprop.0+0x1e/0x40
[ +0.000003] ? handle_mm_fault+0xb2/0x370
[ +0.000003] ksys_read+0x6b/0xf0
[ +0.000004] __x64_sys_read+0x19/0x20
[ +0.000003] do_syscall_64+0x60/0x130
[ +0.000004] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ +0.000003] RIP: 0033:0x7fdf32f147e2
[...]
This error happens when the color log tries to read the gamut remap
information from DCN401 which is not initialized in the dcn401_dpp_funcs
which leads to a null pointer dereference. This commit addresses this
issue by adding a proper guard to access the gamut_remap callback in
case the specific ASIC did not implement this function.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null checker before passing variables
Checks null pointer before passing variables to functions.
This fixes 3 NULL_RETURNS issues reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null checks for 'stream' and 'plane' before dereferencing
This commit adds null checks for the 'stream' and 'plane' variables in
the dcn30_apply_idle_power_optimizations function. These variables were
previously assumed to be null at line 922, but they were used later in
the code without checking if they were null. This could potentially lead
to a null pointer dereference, which would cause a crash.
The null checks ensure that 'stream' and 'plane' are not null before
they are used, preventing potential crashes.
Fixes the below static smatch checker:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:938 dcn30_apply_idle_power_optimizations() error: we previously assumed 'stream' could be null (see line 922)
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:940 dcn30_apply_idle_power_optimizations() error: we previously assumed 'plane' could be null (see line 922)