In the Linux kernel, the following vulnerability has been resolved:
drivers/rapidio/rio_cm.c: prevent possible heap overwrite
In
riocm_cdev_ioctl(RIO_CM_CHAN_SEND)
-> cm_chan_msg_send()
-> riocm_ch_send()
cm_chan_msg_send() checks that userspace didn't send too much data but
riocm_ch_send() failed to check that userspace sent sufficient data. The
result is that riocm_ch_send() can write to fields in the rio_ch_chan_hdr
which were outside the bounds of the space which cm_chan_msg_send()
allocated.
Address this by teaching riocm_ch_send() to check that the entire
rio_ch_chan_hdr was copied in from userspace.
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
huge_pmd_unshare() drops a reference on a page table that may have
previously been shared across processes, potentially turning it into a
normal page table used in another process in which unrelated VMAs can
afterwards be installed.
If this happens in the middle of a concurrent gup_fast(), gup_fast() could
end up walking the page tables of another process. While I don't see any
way in which that immediately leads to kernel memory corruption, it is
really weird and unexpected.
Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(),
just like we do in khugepaged when removing page tables for a THP
collapse.
In the Linux kernel, the following vulnerability has been resolved:
net: ch9200: fix uninitialised access during mii_nway_restart
In mii_nway_restart() the code attempts to call
mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read()
utilises a local buffer called "buff", which is initialised
with control_read(). However "buff" is conditionally
initialised inside control_read():
if (err == size) {
memcpy(data, buf, size);
}
If the condition of "err == size" is not met, then
"buff" remains uninitialised. Once this happens the
uninitialised "buff" is accessed and returned during
ch9200_mdio_read():
return (buff[0] | buff[1] << 8);
The problem stems from the fact that ch9200_mdio_read()
ignores the return value of control_read(), leading to
uinit-access of "buff".
To fix this we should check the return value of
control_read() and return early on error.
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: unshare page tables during VMA split, not before
Currently, __split_vma() triggers hugetlb page table unsharing through
vm_ops->may_split(). This happens before the VMA lock and rmap locks are
taken - which is too early, it allows racing VMA-locked page faults in our
process and racing rmap walks from other processes to cause page tables to
be shared again before we actually perform the split.
Fix it by explicitly calling into the hugetlb unshare logic from
__split_vma() in the same place where THP splitting also happens. At that
point, both the VMA and the rmap(s) are write-locked.
An annoying detail is that we can now call into the helper
hugetlb_unshare_pmds() from two different locking contexts:
1. from hugetlb_split(), holding:
- mmap lock (exclusively)
- VMA lock
- file rmap lock (exclusively)
2. hugetlb_unshare_all_pmds(), which I think is designed to be able to
call us with only the mmap lock held (in shared mode), but currently
only runs while holding mmap lock (exclusively) and VMA lock
Backporting note:
This commit fixes a racy protection that was introduced in commit
b30c14cd6102 ("hugetlb: unshare some PMDs when splitting VMAs"); that
commit claimed to fix an issue introduced in 5.13, but it should actually
also go all the way back.
[jannh@google.com: v2]
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Treat NX as a valid SPTE bit for NPT
Treat the NX bit as valid when using NPT, as KVM will set the NX bit when
the NX huge page mitigation is enabled (mindblowing) and trigger the WARN
that fires on reserved SPTE bits being set.
KVM has required NX support for SVM since commit b26a71a1a5b9 ("KVM: SVM:
Refuse to load kvm_amd if NX support is not available") for exactly this
reason, but apparently it never occurred to anyone to actually test NPT
with the mitigation enabled.
------------[ cut here ]------------
spte = 0x800000018a600ee7, level = 2, rsvd bits = 0x800f0000001fe000
WARNING: CPU: 152 PID: 15966 at arch/x86/kvm/mmu/spte.c:215 make_spte+0x327/0x340 [kvm]
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 10.48.0 01/27/2022
RIP: 0010:make_spte+0x327/0x340 [kvm]
Call Trace:
<TASK>
tdp_mmu_map_handle_target_level+0xc3/0x230 [kvm]
kvm_tdp_mmu_map+0x343/0x3b0 [kvm]
direct_page_fault+0x1ae/0x2a0 [kvm]
kvm_tdp_page_fault+0x7d/0x90 [kvm]
kvm_mmu_page_fault+0xfb/0x2e0 [kvm]
npf_interception+0x55/0x90 [kvm_amd]
svm_invoke_exit_handler+0x31/0xf0 [kvm_amd]
svm_handle_exit+0xf6/0x1d0 [kvm_amd]
vcpu_enter_guest+0xb6d/0xee0 [kvm]
? kvm_pmu_trigger_event+0x6d/0x230 [kvm]
vcpu_run+0x65/0x2c0 [kvm]
kvm_arch_vcpu_ioctl_run+0x355/0x610 [kvm]
kvm_vcpu_ioctl+0x551/0x610 [kvm]
__se_sys_ioctl+0x77/0xc0
__x64_sys_ioctl+0x1d/0x20
do_syscall_64+0x44/0xa0
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
---[ end trace 0000000000000000 ]---
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not allow SET_ID to refer to another table
When doing lookups for sets on the same batch by using its ID, a set from a
different table can be used.
Then, when the table is removed, a reference to the set may be kept after
the set is freed, leading to a potential use-after-free.
When looking for sets by ID, use the table that was used for the lookup by
name, and only return sets belonging to that same table.
This fixes CVE-2022-2586, also reported as ZDI-CAN-17470.
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: pdata-quirks: Fix refcount leak bug
In pdata_quirks_init_clocks(), the loop contains
of_find_node_by_name() but without corresponding of_node_put().
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: Fix refcount leak in omap3xxx_prm_late_init
of_find_matching_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.
In the Linux kernel, the following vulnerability has been resolved:
virtio-gpu: fix a missing check to avoid NULL dereference
'cache_ent' could be set NULL inside virtio_gpu_cmd_get_capset()
and it will lead to a NULL dereference by a lately use of it
(i.e., ptr = cache_ent->caps_cache). Fix it with a NULL check.
[ kraxel: minor codestyle fixup ]
In the Linux kernel, the following vulnerability has been resolved:
net: hinic: avoid kernel hung in hinic_get_stats64()
When using hinic device as a bond slave device, and reading device stats
of master bond device, the kernel may hung.
The kernel panic calltrace as follows:
Kernel panic - not syncing: softlockup: hung tasks
Call trace:
native_queued_spin_lock_slowpath+0x1ec/0x31c
dev_get_stats+0x60/0xcc
dev_seq_printf_stats+0x40/0x120
dev_seq_show+0x1c/0x40
seq_read_iter+0x3c8/0x4dc
seq_read+0xe0/0x130
proc_reg_read+0xa8/0xe0
vfs_read+0xb0/0x1d4
ksys_read+0x70/0xfc
__arm64_sys_read+0x20/0x30
el0_svc_common+0x88/0x234
do_el0_svc+0x2c/0x90
el0_svc+0x1c/0x30
el0_sync_handler+0xa8/0xb0
el0_sync+0x148/0x180
And the calltrace of task that actually caused kernel hungs as follows:
__switch_to+124
__schedule+548
schedule+72
schedule_timeout+348
__down_common+188
__down+24
down+104
hinic_get_stats64+44 [hinic]
dev_get_stats+92
bond_get_stats+172 [bonding]
dev_get_stats+92
dev_seq_printf_stats+60
dev_seq_show+24
seq_read_iter+964
seq_read+220
proc_reg_read+164
vfs_read+172
ksys_read+108
__arm64_sys_read+28
el0_svc_common+132
do_el0_svc+40
el0_svc+24
el0_sync_handler+164
el0_sync+324
When getting device stats from bond, kernel will call bond_get_stats().
It first holds the spinlock bond->stats_lock, and then call
hinic_get_stats64() to collect hinic device's stats.
However, hinic_get_stats64() calls `down(&nic_dev->mgmt_lock)` to
protect its critical section, which may schedule current task out.
And if system is under high pressure, the task cannot be woken up
immediately, which eventually triggers kernel hung panic.
Since previous patch has replaced hinic_dev.tx_stats/rx_stats with local
variable in hinic_get_stats64(), there is nothing need to be protected
by lock, so just removing down()/up() is ok.