Security Vulnerabilities
- CVEs Published In October 2024
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Fix zero-division error when disabling tc cbs
The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider
when offload is disabled") allows the "port_transmit_rate_kbps" to be
set to a value of 0, which is then passed to the "div_s64" function when
tc-cbs is disabled. This leads to a zero-division error.
When tc-cbs is disabled, the idleslope, sendslope, and credit values the
credit values are not required to be configured. Therefore, adding a return
statement after setting the txQ mode to DCB when tc-cbs is disabled would
prevent a zero-division error.
In the Linux kernel, the following vulnerability has been resolved:
gso: fix udp gso fraglist segmentation after pull from frag_list
Detect gso fraglist skbs with corrupted geometry (see below) and
pass these to skb_segment instead of skb_segment_list, as the first
can segment them correctly.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify these skbs, breaking these invariants.
In extreme cases they pull all data into skb linear. For UDP, this
causes a NULL ptr deref in __udpv4_gso_segment_list_csum at
udp_hdr(seg->next)->dest.
Detect invalid geometry due to pull, by checking head_skb size.
Don't just drop, as this may blackhole a destination. Convert to be
able to pass to regular skb_segment.
In the Linux kernel, the following vulnerability has been resolved:
net: gso: fix tcp fraglist segmentation after pull from frag_list
Detect tcp gso fraglist skbs with corrupted geometry (see below) and
pass these to skb_segment instead of skb_segment_list, as the first
can segment them correctly.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify these skbs, breaking these invariants.
In extreme cases they pull all data into skb linear. For TCP, this
causes a NULL ptr deref in __tcpv4_gso_segment_list_csum at
tcp_hdr(seg->next).
Detect invalid geometry due to pull, by checking head_skb size.
Don't just drop, as this may blackhole a destination. Convert to be
able to pass to regular skb_segment.
Approach and description based on a patch by Willem de Bruijn.
In the Linux kernel, the following vulnerability has been resolved:
vrf: revert "vrf: Remove unnecessary RCU-bh critical section"
This reverts commit 504fc6f4f7f681d2a03aa5f68aad549d90eab853.
dev_queue_xmit_nit is expected to be called with BH disabled.
__dev_queue_xmit has the following:
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
rcu_read_lock_bh();
VRF must follow this invariant. The referenced commit removed this
protection. Which triggered a lockdep warning:
================================
WARNING: inconsistent lock state
6.11.0 #1 Tainted: G W
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
btserver/134819 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff8882da30c118 (rlock-AF_PACKET){+.?.}-{2:2}, at: tpacket_rcv+0x863/0x3b30
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
packet_rcv+0xa33/0x1320
__netif_receive_skb_core.constprop.0+0xcb0/0x3a90
__netif_receive_skb_list_core+0x2c9/0x890
netif_receive_skb_list_internal+0x610/0xcc0
[...]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rlock-AF_PACKET);
<Interrupt>
lock(rlock-AF_PACKET);
*** DEADLOCK ***
Call Trace:
<TASK>
dump_stack_lvl+0x73/0xa0
mark_lock+0x102e/0x16b0
__lock_acquire+0x9ae/0x6170
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
tpacket_rcv+0x863/0x3b30
dev_queue_xmit_nit+0x709/0xa40
vrf_finish_direct+0x26e/0x340 [vrf]
vrf_l3_out+0x5f4/0xe80 [vrf]
__ip_local_out+0x51e/0x7a0
[...]
In the Linux kernel, the following vulnerability has been resolved:
media: venus: fix use after free bug in venus_remove due to race condition
in venus_probe, core->work is bound with venus_sys_error_handler, which is
used to handle error. The code use core->sys_err_done to make sync work.
The core->work is started in venus_event_notify.
If we call venus_remove, there might be an unfished work. The possible
sequence is as follows:
CPU0 CPU1
|venus_sys_error_handler
venus_remove |
hfi_destroy |
venus_hfi_destroy |
kfree(hdev); |
|hfi_reinit
|venus_hfi_queues_reinit
|//use hdev
Fix it by canceling the work in venus_remove.
In the Linux kernel, the following vulnerability has been resolved:
aoe: fix the potential use-after-free problem in more places
For fixing CVE-2023-6270, f98364e92662 ("aoe: fix the potential
use-after-free problem in aoecmd_cfg_pkts") makes tx() calling dev_put()
instead of doing in aoecmd_cfg_pkts(). It avoids that the tx() runs
into use-after-free.
Then Nicolai Stange found more places in aoe have potential use-after-free
problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe()
and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push
packet to tx queue. So they should also use dev_hold() to increase the
refcnt of skb->dev.
On the other hand, moving dev_put() to tx() causes that the refcnt of
skb->dev be reduced to a negative value, because corresponding
dev_hold() are not called in revalidate(), aoecmd_ata_rw(), resend(),
probe(), and aoecmd_cfg_rsp(). This patch fixed this issue.
In the Linux kernel, the following vulnerability has been resolved:
ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free
When calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(),
the 'ppath' is updated but it is the 'path' that is freed, thus potentially
triggering a double-free in the following process:
ext4_ext_replay_update_ex
ppath = path
ext4_force_split_extent_at(&ppath)
ext4_split_extent_at
ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path) ---> path First freed
*orig_path = path = NULL ---> null ppath
kfree(path) ---> path double-free !!!
So drop the unnecessary ppath and use path directly to avoid this problem.
And use ext4_find_extent() directly to update path, avoiding unnecessary
memory allocation and freeing. Also, propagate the error returned by
ext4_find_extent() instead of using strange error codes.
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Prevent out of bounds access in performance query extensions
Check that the number of perfmons userspace is passing in the copy and
reset extensions is not greater than the internal kernel storage where
the ids will be copied into.
In the Linux kernel, the following vulnerability has been resolved:
i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume
In case there is any sort of clock controller attached to this I2C bus
controller, for example Versaclock or even an AIC32x4 I2C codec, then
an I2C transfer triggered from the clock controller clk_ops .prepare
callback may trigger a deadlock on drivers/clk/clk.c prepare_lock mutex.
This is because the clock controller first grabs the prepare_lock mutex
and then performs the prepare operation, including its I2C access. The
I2C access resumes this I2C bus controller via .runtime_resume callback,
which calls clk_prepare_enable(), which attempts to grab the prepare_lock
mutex again and deadlocks.
Since the clock are already prepared since probe() and unprepared in
remove(), use simple clk_enable()/clk_disable() calls to enable and
disable the clock on runtime suspend and resume, to avoid hitting the
prepare_lock mutex.
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: reserve space for inline xattr before attaching reflink tree
One of our customers reported a crash and a corrupted ocfs2 filesystem.
The crash was due to the detection of corruption. Upon troubleshooting,
the fsck -fn output showed the below corruption
[EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record,
but fsck believes the largest valid value is 227. Clamp the next record value? n
The stat output from the debugfs.ocfs2 showed the following corruption
where the "Next Free Rec:" had overshot the "Count:" in the root metadata
block.
Inode: 33080590 Mode: 0640 Generation: 2619713622 (0x9c25a856)
FS Generation: 904309833 (0x35e6ac49)
CRC32: 00000000 ECC: 0000
Type: Regular Attr: 0x0 Flags: Valid
Dynamic Features: (0x16) HasXattr InlineXattr Refcounted
Extended Attributes Block: 0 Extended Attributes Inline Size: 256
User: 0 (root) Group: 0 (root) Size: 281320357888
Links: 1 Clusters: 141738
ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024
atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024
mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024
dtime: 0x0 -- Wed Dec 31 17:00:00 1969
Refcount Block: 2777346
Last Extblk: 2886943 Orphan Slot: 0
Sub Alloc Slot: 0 Sub Alloc Bit: 14
Tree Depth: 1 Count: 227 Next Free Rec: 230
## Offset Clusters Block#
0 0 2310 2776351
1 2310 2139 2777375
2 4449 1221 2778399
3 5670 731 2779423
4 6401 566 2780447
....... .... .......
....... .... .......
The issue was in the reflink workfow while reserving space for inline
xattr. The problematic function is ocfs2_reflink_xattr_inline(). By the
time this function is called the reflink tree is already recreated at the
destination inode from the source inode. At this point, this function
reserves space for inline xattrs at the destination inode without even
checking if there is space at the root metadata block. It simply reduces
the l_count from 243 to 227 thereby making space of 256 bytes for inline
xattr whereas the inode already has extents beyond this index (in this
case up to 230), thereby causing corruption.
The fix for this is to reserve space for inline metadata at the destination
inode before the reflink tree gets recreated. The customer has verified the
fix.