Linux: >> Linux Kernel >> 2.6.23.7 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Fix loop termination condition in gss_free_in_token_pages()
The in_token->pages[] array is not NULL terminated. This results in
the following KASAN splat:
KASAN: maybe wild-memory-access in range [0x04a2013400000008-0x04a201340000000f]
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-21
In the Linux kernel, the following vulnerability has been resolved:
soundwire: cadence: fix invalid PDI offset
For some reason, we add an offset to the PDI, presumably to skip the
PDI0 and PDI1 which are reserved for BPT.
This code is however completely wrong and leads to an out-of-bounds
access. We were just lucky so far since we used only a couple of PDIs
and remained within the PDI array bounds.
A Fixes: tag is not provided since there are no known platforms where
the out-of-bounds would be accessed, and the initial code had problems
as well.
A follow-up patch completely removes this useless offset.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-06-21
In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix hang in usb_kill_urb by adding memory barriers
The syzbot fuzzer has identified a bug in which processes hang waiting
for usb_kill_urb() to return. It turns out the issue is not unlinking
the URB; that works just fine. Rather, the problem arises when the
wakeup notification that the URB has completed is not received.
The reason is memory-access ordering on SMP systems. In outline form,
usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on
different CPUs perform the following actions:
CPU 0 CPU 1
---------------------------- ---------------------------------
usb_kill_urb(): __usb_hcd_giveback_urb():
... ...
atomic_inc(&urb->reject); atomic_dec(&urb->use_count);
... ...
wait_event(usb_kill_urb_queue,
atomic_read(&urb->use_count) == 0);
if (atomic_read(&urb->reject))
wake_up(&usb_kill_urb_queue);
Confining your attention to urb->reject and urb->use_count, you can
see that the overall pattern of accesses on CPU 0 is:
write urb->reject, then read urb->use_count;
whereas the overall pattern of accesses on CPU 1 is:
write urb->use_count, then read urb->reject.
This pattern is referred to in memory-model circles as SB (for "Store
Buffering"), and it is well known that without suitable enforcement of
the desired order of accesses -- in the form of memory barriers -- it
is entirely possible for one or both CPUs to execute their reads ahead
of their writes. The end result will be that sometimes CPU 0 sees the
old un-decremented value of urb->use_count while CPU 1 sees the old
un-incremented value of urb->reject. Consequently CPU 0 ends up on
the wait queue and never gets woken up, leading to the observed hang
in usb_kill_urb().
The same pattern of accesses occurs in usb_poison_urb() and the
failure pathway of usb_hcd_submit_urb().
The problem is fixed by adding suitable memory barriers. To provide
proper memory-access ordering in the SB pattern, a full barrier is
required on both CPUs. The atomic_inc() and atomic_dec() accesses
themselves don't provide any memory ordering, but since they are
present, we can use the optimized smp_mb__after_atomic() memory
barrier in the various routines to obtain the desired effect.
This patch adds the necessary memory barriers.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Forcibly leave nested virt when SMM state is toggled
Forcibly leave nested virtualization operation if userspace toggles SMM
state via KVM_SET_VCPU_EVENTS or KVM_SYNC_X86_EVENTS. If userspace
forces the vCPU out of SMM while it's post-VMXON and then injects an SMI,
vmx_enter_smm() will overwrite vmx->nested.smm.vmxon and end up with both
vmxon=false and smm.vmxon=false, but all other nVMX state allocated.
Don't attempt to gracefully handle the transition as (a) most transitions
are nonsencial, e.g. forcing SMM while L2 is running, (b) there isn't
sufficient information to handle all transitions, e.g. SVM wants access
to the SMRAM save state, and (c) KVM_SET_VCPU_EVENTS must precede
KVM_SET_NESTED_STATE during state restore as the latter disallows putting
the vCPU into L2 if SMM is active, and disallows tagging the vCPU as
being post-VMXON in SMM if SMM is not active.
Abuse of KVM_SET_VCPU_EVENTS manifests as a WARN and memory leak in nVMX
due to failure to free vmcs01's shadow VMCS, but the bug goes far beyond
just a memory leak, e.g. toggling SMM on while L2 is active puts the vCPU
in an architecturally impossible state.
WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline]
WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656
Modules linked in:
CPU: 1 PID: 3606 Comm: syz-executor725 Not tainted 5.17.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline]
RIP: 0010:free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656
Code: <0f> 0b eb b3 e8 8f 4d 9f 00 e9 f7 fe ff ff 48 89 df e8 92 4d 9f 00
Call Trace:
<TASK>
kvm_arch_vcpu_destroy+0x72/0x2f0 arch/x86/kvm/x86.c:11123
kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline]
kvm_destroy_vcpus+0x11f/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:460
kvm_free_vcpus arch/x86/kvm/x86.c:11564 [inline]
kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:11676
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1217 [inline]
kvm_put_kvm+0x4fa/0xb00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1250
kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1273
__fput+0x286/0x9f0 fs/file_table.c:311
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
exit_task_work include/linux/task_work.h:32 [inline]
do_exit+0xb29/0x2a30 kernel/exit.c:806
do_group_exit+0xd2/0x2f0 kernel/exit.c:935
get_signal+0x4b0/0x28c0 kernel/signal.c:2862
arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Wrap dcn301_calculate_wm_and_dlg for FPU.
Mirrors the logic for dcn30. Cue lots of WARNs and some
kernel panics without this fix.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
ASoC: hdmi-codec: Fix OOB memory accesses
Correct size of iec_status array by changing it to the size of status
array of the struct snd_aes_iec958. This fixes out-of-bounds slab
read accesses made by memcpy() of the hdmi-codec driver. This problem
is reported by KASAN.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
ovl: fix NULL pointer dereference in copy up warning
This patch is fixing a NULL pointer dereference to get a recently
introduced warning message working.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
block: Fix wrong offset in bio_truncate()
bio_truncate() clears the buffer outside of last block of bdev, however
current bio_truncate() is using the wrong offset of page. So it can
return the uninitialized data.
This happened when both of truncated/corrupted FS and userspace (via
bdev) are trying to read the last of bdev.
CVSS Score
7.5
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
mm/kmemleak: avoid scanning potential huge holes
When using devm_request_free_mem_region() and devm_memremap_pages() to
add ZONE_DEVICE memory, if requested free mem region's end pfn were
huge(e.g., 0x400000000), the node_end_pfn() will be also huge (see
move_pfn_range_to_zone()). Thus it creates a huge hole between
node_start_pfn() and node_end_pfn().
We found on some AMD APUs, amdkfd requested such a free mem region and
created a huge hole. In such a case, following code snippet was just
doing busy test_bit() looping on the huge hole.
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
struct page *page = pfn_to_online_page(pfn);
if (!page)
continue;
...
}
So we got a soft lockup:
watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [bash:1221]
CPU: 6 PID: 1221 Comm: bash Not tainted 5.15.0-custom #1
RIP: 0010:pfn_to_online_page+0x5/0xd0
Call Trace:
? kmemleak_scan+0x16a/0x440
kmemleak_write+0x306/0x3a0
? common_file_perm+0x72/0x170
full_proxy_write+0x5c/0x90
vfs_write+0xb9/0x260
ksys_write+0x67/0xe0
__x64_sys_write+0x1a/0x20
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
I did some tests with the patch.
(1) amdgpu module unloaded
before the patch:
real 0m0.976s
user 0m0.000s
sys 0m0.968s
after the patch:
real 0m0.981s
user 0m0.000s
sys 0m0.973s
(2) amdgpu module loaded
before the patch:
real 0m35.365s
user 0m0.000s
sys 0m35.354s
after the patch:
real 0m1.049s
user 0m0.000s
sys 0m1.042s
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-20
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free after failure to create a snapshot
At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and
then attach it to the transaction's list of pending snapshots. After that
we call btrfs_commit_transaction(), and if that returns an error we jump
to 'fail' label, where we kfree() the pending snapshot structure. This can
result in a later use-after-free of the pending snapshot:
1) We allocated the pending snapshot and added it to the transaction's
list of pending snapshots;
2) We call btrfs_commit_transaction(), and it fails either at the first
call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups().
In both cases, we don't abort the transaction and we release our
transaction handle. We jump to the 'fail' label and free the pending
snapshot structure. We return with the pending snapshot still in the
transaction's list;
3) Another task commits the transaction. This time there's no error at
all, and then during the transaction commit it accesses a pointer
to the pending snapshot structure that the snapshot creation task
has already freed, resulting in a user-after-free.
This issue could actually be detected by smatch, which produced the
following warning:
fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list
So fix this by not having the snapshot creation ioctl directly add the
pending snapshot to the transaction's list. Instead add the pending
snapshot to the transaction handle, and then at btrfs_commit_transaction()
we add the snapshot to the list only when we can guarantee that any error
returned after that point will result in a transaction abort, in which
case the ioctl code can safely free the pending snapshot and no one can
access it anymore.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-06-20