In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Make it so that a waiting process can be aborted
When sendmsg() creates an rxrpc call, it queues it to wait for a connection
and channel to be assigned and then waits before it can start shovelling
data as the encrypted DATA packet content includes a summary of the
connection parameters.
However, sendmsg() may get interrupted before a connection gets assigned
and further sendmsg() calls will fail with EBUSY until an assignment is
made.
Fix this so that the call can at least be aborted without failing on
EBUSY. We have to be careful here as sendmsg() mustn't be allowed to start
the call timer if the call doesn't yet have a connection assigned as an
oops may follow shortly thereafter.
In the Linux kernel, the following vulnerability has been resolved:
media: netup_unidvb: fix use-after-free at del_timer()
When Universal DVB card is detaching, netup_unidvb_dma_fini()
uses del_timer() to stop dma->timeout timer. But when timer
handler netup_unidvb_dma_timeout() is running, del_timer()
could not stop it. As a result, the use-after-free bug could
happen. The process is shown below:
(cleanup routine) | (timer routine)
| mod_timer(&dev->tx_sim_timer, ..)
netup_unidvb_finidev() | (wait a time)
netup_unidvb_dma_fini() | netup_unidvb_dma_timeout()
del_timer(&dma->timeout); |
| ndev->pci_dev->dev //USE
Fix by changing del_timer() to del_timer_sync().
In the Linux kernel, the following vulnerability has been resolved:
media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()
In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach az6007_i2c_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix memleak due to fentry attach failure
If it fails to attach fentry, the allocated bpf trampoline image will be
left in the system. That can be verified by checking /proc/kallsyms.
This meamleak can be verified by a simple bpf program as follows:
SEC("fentry/trap_init")
int fentry_run()
{
return 0;
}
It will fail to attach trap_init because this function is freed after
kernel init, and then we can find the trampoline image is left in the
system by checking /proc/kallsyms.
$ tail /proc/kallsyms
ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf]
ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf]
$ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'"
[2522] FUNC 'trap_init' type_id=119 linkage=static
$ echo $((6442453466 & 0x7fffffff))
2522
Note that there are two left bpf trampoline images, that is because the
libbpf will fallback to raw tracepoint if -EINVAL is returned.
In the Linux kernel, the following vulnerability has been resolved:
jfs: jfs_dmap: Validate db_l2nbperpage while mounting
In jfs_dmap.c at line 381, BLKTODMAP is used to get a logical block
number inside dbFree(). db_l2nbperpage, which is the log2 number of
blocks per page, is passed as an argument to BLKTODMAP which uses it
for shifting.
Syzbot reported a shift out-of-bounds crash because db_l2nbperpage is
too big. This happens because the large value is set without any
validation in dbMount() at line 181.
Thus, make sure that db_l2nbperpage is correct while mounting.
Max number of blocks per page = Page size / Min block size
=> log2(Max num_block per page) = log2(Page size / Min block size)
= log2(Page size) - log2(Min block size)
=> Max db_l2nbperpage = L2PSIZE - L2MINBLOCKSIZE
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus_core) Fix NULL pointer dereference
Pass i2c_client to _pmbus_is_enabled to drop the assumption
that a regulator device is passed in.
This will fix the issue of a NULL pointer dereference when called from
_pmbus_get_flags.
In the Linux kernel, the following vulnerability has been resolved:
ublk: fail to recover device if queue setup is interrupted
In ublk_ctrl_end_recovery(), if wait_for_completion_interruptible() is
interrupted by signal, queues aren't setup successfully yet, so we
have to fail UBLK_CMD_END_USER_RECOVERY, otherwise kernel oops can be
triggered.
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Load L1's TSC multiplier based on L1 state, not L2 state
When emulating nested VM-Exit, load L1's TSC multiplier if L1's desired
ratio doesn't match the current ratio, not if the ratio L1 is using for
L2 diverges from the default. Functionally, the end result is the same
as KVM will run L2 with L1's multiplier if L2's multiplier is the default,
i.e. checking that L1's multiplier is loaded is equivalent to checking if
L2 has a non-default multiplier.
However, the assertion that TSC scaling is exposed to L1 is flawed, as
userspace can trigger the WARN at will by writing the MSR and then
updating guest CPUID to hide the feature (modifying guest CPUID is
allowed anytime before KVM_RUN). E.g. hacking KVM's state_test
selftest to do
vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0);
vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR);
after restoring state in a new VM+vCPU yields an endless supply of:
------------[ cut here ]------------
WARNING: CPU: 10 PID: 206939 at arch/x86/kvm/svm/nested.c:1105
nested_svm_vmexit+0x6af/0x720 [kvm_amd]
Call Trace:
nested_svm_exit_handled+0x102/0x1f0 [kvm_amd]
svm_handle_exit+0xb9/0x180 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
? trace_hardirqs_off+0x4d/0xa0
__se_sys_ioctl+0x7a/0xc0
__x64_sys_ioctl+0x21/0x30
do_syscall_64+0x41/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Unlike the nested VMRUN path, hoisting the svm->tsc_scaling_enabled check
into the if-statement is wrong as KVM needs to ensure L1's multiplier is
loaded in the above scenario. Alternatively, the WARN_ON() could simply
be deleted, but that would make KVM's behavior even more subtle, e.g. it's
not immediately obvious why it's safe to write MSR_AMD64_TSC_RATIO when
checking only tsc_ratio_msr.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211_hwsim: Fix possible NULL dereference
In a call to mac80211_hwsim_select_tx_link() the sta pointer might
be NULL, thus need to check that it is not NULL before accessing it.