| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iomap: iomap: fix memory corruption when recording errors during writeback
Every now and then I see this crash on arm64:
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8
Buffer I/O error on dev dm-0, logical block 8733687, async page read
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
user pgtable: 64k pages, 42-bit VAs, pgdp=0000000139750000
[00000000000000f8] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000, pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Buffer I/O error on dev dm-0, logical block 8733688, async page read
Dumping ftrace buffer:
Buffer I/O error on dev dm-0, logical block 8733689, async page read
(ftrace buffer empty)
XFS (dm-0): log I/O error -5
Modules linked in: dm_thin_pool dm_persistent_data
XFS (dm-0): Metadata I/O Error (0x1) detected at xfs_trans_read_buf_map+0x1ec/0x590 [xfs] (fs/xfs/xfs_trans_buf.c:296).
dm_bio_prison
XFS (dm-0): Please unmount the filesystem and rectify the problem(s)
XFS (dm-0): xfs_imap_lookup: xfs_ialloc_read_agi() returned error -5, agno 0
dm_bufio dm_log_writes xfs nft_chain_nat xt_REDIRECT nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip6t_REJECT
potentially unexpected fatal signal 6.
nf_reject_ipv6
potentially unexpected fatal signal 6.
ipt_REJECT nf_reject_ipv4
CPU: 1 PID: 122166 Comm: fsstress Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7
rpcsec_gss_krb5 auth_rpcgss xt_tcpudp ip_set_hash_ip ip_set_hash_net xt_set nft_compat ip_set_hash_mac ip_set nf_tables
Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021
pstate: 60001000 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
ip_tables
pc : 000003fd6d7df200
x_tables
lr : 000003fd6d7df1ec
overlay nfsv4
CPU: 0 PID: 54031 Comm: u4:3 Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7405
Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021
Workqueue: writeback wb_workfn
sp : 000003ffd9522fd0
(flush-253:0)
pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--)
pc : errseq_set+0x1c/0x100
x29: 000003ffd9522fd0 x28: 0000000000000023 x27: 000002acefeb6780
x26: 0000000000000005 x25: 0000000000000001 x24: 0000000000000000
x23: 00000000ffffffff x22: 0000000000000005
lr : __filemap_set_wb_err+0x24/0xe0
x21: 0000000000000006
sp : fffffe000f80f760
x29: fffffe000f80f760 x28: 0000000000000003 x27: fffffe000f80f9f8
x26: 0000000002523000 x25: 00000000fffffffb x24: fffffe000f80f868
x23: fffffe000f80fbb0 x22: fffffc0180c26a78 x21: 0000000002530000
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000001 x13: 0000000000470af3 x12: fffffc0058f70000
x11: 0000000000000040 x10: 0000000000001b20 x9 : fffffe000836b288
x8 : fffffc00eb9fd480 x7 : 0000000000f83659 x6 : 0000000000000000
x5 : 0000000000000869 x4 : 0000000000000005 x3 : 00000000000000f8
x20: 000003fd6d740020 x19: 000000000001dd36 x18: 0000000000000001
x17: 000003fd6d78704c x16: 0000000000000001 x15: 000002acfac87668
x2 : 0000000000000ffa x1 : 00000000fffffffb x0 : 00000000000000f8
Call trace:
errseq_set+0x1c/0x100
__filemap_set_wb_err+0x24/0xe0
iomap_do_writepage+0x5e4/0xd5c
write_cache_pages+0x208/0x674
iomap_writepages+0x34/0x60
xfs_vm_writepages+0x8c/0xcc [xfs 7a861f39c43631f15d3a5884246ba5035d4ca78b]
x14: 0000000000000000 x13: 2064656e72757465 x12: 0000000000002180
x11: 000003fd6d8a82d0 x10: 0000000000000000 x9 : 000003fd6d8ae288
x8 : 0000000000000083 x7 : 00000000ffffffff x6 : 00000000ffffffee
x5 : 00000000fbad2887 x4 : 000003fd6d9abb58 x3 : 000003fd6d740020
x2 : 0000000000000006 x1 : 000000000001dd36 x0 : 0000000000000000
CPU:
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
virt: acrn: Fix irqfd use-after-free during eventfd shutdown
acrn_irqfd_deassign() and the eventfd EPOLLHUP wakeup can race and free
the same struct hsm_irqfd:
CPU0 CPU1
---- ----
eventfd_release()
wake_up_poll(EPOLLHUP)
hsm_irqfd_wakeup()
queue_work(&irqfd->shutdown)
acrn_irqfd_deassign()
hsm_irqfd_shutdown()
list_del_init()
eventfd_ctx_remove_wait_queue()
eventfd_ctx_put()
kfree(irqfd)
hsm_irqfd_shutdown_work()
container_of(work, ..., shutdown)
irqfd->vm <-- use-after-free
The deassign path freed the irqfd while a shutdown work item was
already queued by EPOLLHUP (or vice versa), so the work item could
resurrect a dangling pointer through container_of().
Switch to the lifetime model used by KVM irqfds:
- Deassign/deinit only deactivate the irqfd: remove it from vm->irqfds
under irqfds_lock and queue the cleanup work.
- hsm_irqfd_shutdown_work() becomes the sole owner that unhooks the
eventfd waitqueue entry, drops the eventfd reference and frees the
irqfd.
- A new HSM_IRQFD_FLAG_SHUTDOWN bit guarded by test_and_set_bit()
ensures the cleanup work is queued at most once, no matter how many
of {EPOLLHUP, deassign, deinit} fire concurrently. This is safe to
call from the waitqueue callback, which runs with wqh->lock held and
IRQs disabled and therefore cannot take irqfds_lock.
- acrn_irqfd_deassign() flushes vm->irqfd_wq before returning so the
eventfd is fully detached on return. acrn_irqfd_deinit() deactivates
every irqfd, flushes the workqueue and only then destroys it, so no
path can queue_work() onto a torn-down workqueue.
- acrn_irqfd_assign() now installs the eventfd waitqueue entry and
publishes the irqfd to vm->irqfds under irqfds_lock, so the irqfd is
never visible to deassign/deinit before its waitqueue entry is in
place, and any EPOLLHUP that fires in the assign window queues
cleanup work that blocks on irqfds_lock until publication is done. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI/proc: Use file_ns_capable() when checking config space read access
proc_bus_pci_read() decides how much of the config space is readable based
on capable(CAP_SYS_ADMIN), which checks the credentials of the task calling
read(), not the credentials of the process that opened the file.
The sysfs equivalent, pci_read_config(), has checked the credentials of the
opening process since commit de139a339395 ("pci: check caps from sysfs file
open to read device dependent config space"), so a privileged process can
open the config space file and pass the file descriptor to an unprivileged
process (for example, a process running a KVM guest with an assigned
device), which can then read the entire config space. The check was
subsequently routed through the LSM framework in commit 47970b1b2aa6 ("pci:
use security_capable() when checking capablities during config space read")
and converted to the dedicated helper in commit ab0fa82b2df9 ("pci-sysfs:
use proper file capability helper function").
Thus, the two interfaces check the same capability against different
credentials. Checking the credentials of the task calling read() makes the
outcome depend on who reads rather than who opened, so the restriction is
bypassed whenever a more privileged process reads through the descriptor.
Checking the credentials recorded in file->f_cred settles the decision at
open() time and ties it to the file, where it cannot change with the
caller.
Use file_ns_capable() to check CAP_SYS_ADMIN against the credentials in
effect when the file was opened, bringing the procfs interface in line with
the sysfs behaviour.
As a result, a file descriptor opened by a privileged process and passed to
an unprivileged one now allows the entire config space to be read through
procfs, matching sysfs. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone()
initializes struct pages early in boot to satisfy an allocation.
With a large CMA reservation in place, the ranges deferred_init_memmap()
finds may not add up to the allocation it was asked for, and the function
ends up initializing the memory map of the entire zone and still falls
short.
That is fine in itself: the function accounts for it and leaves the
caller to decide whether it now has enough memory.
However, the update of pgdat->first_deferred_pfn that tracks where
uninitialized memory map starts could overflow.
If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and
some deferred struct pages were initialized, pgdat->first_deferred_pfn
would point past the end of the node's memory.
deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and
hits a BUG_ON(), because it expects a pfn within its node.
For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
and CONFIG_CMA=y using the following qemu command line
qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \
-append "nokaslr cma=4768M@0x100000000"
the kernel panics:
kernel BUG at mm/mm_init.c:2131!
CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1
RIP: 0010:deferred_init_memmap+0x1b8/0x1c0
RAX: 0000000000236000 R13: 0000000000238000
Call Trace:
kthread+0xdf/0x120
ret_from_fork+0x187/0x250
Make sure that the update of pgdta->first_deferred_pfn does not overflow
when the entire zone's (and therefore node's) memory map is initialized.
[rppt: massaged the changelog] |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: zstd: fix lost wakeup when waiting for a workspace
A writer can sleep forever in zstd_get_workspace() even though a workspace
is free. When zstd_alloc_workspace() fails, the task is queued on
zwsm->wait and schedules unconditionally, never re-testing the pool.
zstd_put_workspace() publishes the workspace and then calls cond_wake_up(),
which only wakes when a sleeper is already visible, so a workspace returned
between the failed allocation and prepare_to_wait() wakes nobody. The
window is wide: zstd_alloc_workspace() goes through kvmalloc() and may
enter reclaim.
Only a max level workspace triggers the wakeup and one is deliberately kept
allocated as the fallback every waiter waits for, so once its wakeup is
lost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens
to return one. Re-check the pool after prepare_to_wait() has published the
waiter, and use the workspace if one turned up. |
| In the Linux kernel, the following vulnerability has been resolved:
ceph: properly decrypt filenames in vmalloc() buffers
The fscrypt subsystem uses the scatterlist crypto API, inheriting its
requirement that any buffers are in the linear mapping region. However,
the messenger client uses kvmalloc() to create buffers for messages,
which will occasionally place those buffers in the vmalloc() region when
physical memory fragmentation doesn't permit a large enough kmalloc().
The various callers of ceph_fname_to_usr() directly pass (slices of) raw
messages from the MDS without considering that the messages may be in
vmalloc() buffers, resulting in oopses especially on non-x86 platforms
(see 'Closes:' for more details and a reproducer).
Make ceph_fname_to_usr() explicitly tolerant of vmalloc()-allocated
fname->ctext, fname->name, and/or oname->name buffers, using `tname`
(which, when non-null, must be a linear address; when null, is briefly
allocated as necessary) as a bounce buffer to avoid passing any
inappropriate addresses to fscrypt_fname_disk_to_usr().
Additionally change parse_reply_info_readdir() -- the only function to
supply its own `tname` -- to follow the new "tname must never come from
vmalloc()" rule by passing NULL when the message is not in the linear
region. Though this causes a per-dentry kmalloc()+kfree(), this overhead
exists only when processing the minority of messages that spill into
vmalloc(). My (crude) testing puts this at only about 1 in 8,000 readdir
messages. Still, if the overhead proves unreasonable in the future, it
is easy enough to mitigate: a future change could allocate a bounce
buffer in parse_reply_info_readdir() and use that as `tname` instead. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_teql: restore skb->dev on the slave failure path
teql_master_xmit() sets skb->dev = slave before calling the slave's
ndo_start_xmit(), but never restores it when that transmit fails. The
skb then walks on to the next slave still pointing at the previous one.
If a later slave has no resolved neighbour, teql_resolve() hands the skb
to neigh_event_send(), which queues it on that neighbour's arp_queue
with the stale skb->dev. skb->dev holds no reference, so deleting the
previous slave frees the net_device while the skb is still queued.
Whatever runs next on that skb - arp_error_report() on timeout, or
neigh_direct_output() -> dev_queue_xmit() once the neighbour resolves -
causes a UAF like the one below:
BUG: KASAN: slab-use-after-free in __icmp_send (net/ipv4/icmp.c:914 (discriminator 2))
Read of size 4 at addr ffff888106e100b0 by task flood_packet/527
CPU: 0 UID: 0 PID: 527 Comm: flood_packet Not tainted 7.2.0-rc6-g594d90519502 #1 PREEMPT(lazy)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_report (mm/kasan/report.c:378 mm/kasan/report.c:482)
? __pfx__raw_spin_lock_irqsave (./include/asm-generic/qrwlock.h:122 (discriminator 4))
? __icmp_send (net/ipv4/icmp.c:914 (discriminator 2))
kasan_report (mm/kasan/report.c:595)
? __icmp_send (net/ipv4/icmp.c:914 (discriminator 2))
__icmp_send (net/ipv4/icmp.c:914 (discriminator 2))
[...]
ipv4_link_failure (net/ipv4/route.c:1251 net/ipv4/route.c:1258)
? __pfx_ipv4_link_failure (./include/linux/skbuff.h:4327)
? _raw_write_lock (./include/linux/instrumented.h:55 ./include/linux/atomic/atomic-instrumented.h:1301 ./include/asm-generic/qrwlock.h:98 ./include/linux/rwlock_api_smp.h:230 kernel/locking/spinlock.c:304)
? __pfx__raw_write_lock (kernel/locking/spinlock.c:175)
arp_error_report (./include/net/dst.h:438 net/ipv4/arp.c:296)
neigh_invalidate (net/core/neighbour.c:1077)
neigh_timer_handler (net/core/neighbour.c:1169)
[...]
Allocated by task 505:
kasan_save_stack (mm/kasan/common.c:57)
kasan_save_track (mm/kasan/common.c:78)
__kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415)
__kvmalloc_node_noprof (./include/linux/kasan.h:263 mm/slub.c:5334 mm/slub.c:6905)
alloc_netdev_mqs (net/core/dev.c:12055 (discriminator 2))
rtnl_create_link (net/core/rtnetlink.c:3721)
rtnl_newlink (net/core/rtnetlink.c:3903 net/core/rtnetlink.c:4044 net/core/rtnetlink.c:4159)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
[...]
Freed by task 536:
kasan_save_stack (mm/kasan/common.c:57)
kasan_save_track (mm/kasan/common.c:78)
kasan_save_free_info (mm/kasan/generic.c:584)
__kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285)
kfree (./include/linux/kasan.h:235 mm/slub.c:2677 mm/slub.c:6377 mm/slub.c:6692)
device_release (drivers/base/core.c:2636)
kobject_put (lib/kobject.c:689 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
netdev_run_todo (net/core/dev.c:11756)
rtnl_dellink (net/core/rtnetlink.c:157 ./include/linux/rtnetlink.h:135 net/core/rtnetlink.c:3651)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
[...]
Fix this by restoring skb->dev to the master at the end of each slave's
iteration. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: server: fix leak of ksmbd_ipc_login_request_ext() returned buffer
Free it unconditionally after ksmbd_alloc_user() calls.
kmemleak splat:
unreferenced object 0xffff888103b83540 (size 192):
comm "pool-0", pid 16970, jiffies 4377290937
hex dump (first 32 bytes):
00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 408ccc66):
__kvmalloc_node_noprof+0x730/0x920
handle_generic_event+0xec/0x1a0 [ksmbd]
genl_family_rcv_msg_doit+0xe0/0x130
genl_rcv_msg+0x181/0x290
netlink_rcv_skb+0x4f/0x100
genl_rcv+0x28/0x40
netlink_unicast+0x1e6/0x2c0
netlink_sendmsg+0x20a/0x450
____sys_sendmsg+0x2e8/0x310
___sys_sendmsg+0x78/0xc0
__sys_sendmsg+0x63/0xc0
do_syscall_64+0xa1/0x670
entry_SYSCALL_64_after_hwframe+0x76/0x7e |
| In the Linux kernel, the following vulnerability has been resolved:
ARM: 9483/1: select HAVE_POSIX_CPU_TIMERS_TASK_WORK
Commit c6e61c06d606 ("ARM: 9463/1: Allow to enable RT") enabled PREEMPT_RT
on ARM but did not select HAVE_POSIX_CPU_TIMERS_TASK_WORK. This leaves
CONFIG_POSIX_CPU_TIMERS_TASK_WORK disabled, so CPU timers expire in hard
IRQ context.
On PREEMPT_RT this makes run_posix_cpu_timers() take the sleeping
sighand->siglock:
BUG: sleeping function called from invalid context at spinlock_rt.c:48
rt_spin_lock from lock_task_sighand
lock_task_sighand from run_posix_cpu_timers
run_posix_cpu_timers from update_process_times
ARM handles TIF_NOTIFY_RESUME on all return-to-user paths, including v7-M.
ARM32 KVM host support was removed by commit 541ad0150ca4 ("arm: Remove
32bit KVM host support"), so the select need not be conditional on KVM.
Select it to defer POSIX CPU timer expiry to task context.
Reproduced with setrlimit(RLIMIT_CPU, ...) and a busy loop. The same path
is used by setitimer(ITIMER_PROF or ITIMER_VIRTUAL) and POSIX CPU timers
created with timer_create(). |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate ipc response length before dereferencing its fields
ipc_validate_msg() computes the expected message size by reading length
fields out of the response buffer supplied by the userspace ksmbd daemon
(payload_sz, session_key_len, ngroups, ...). Those fields are read before
the buffer is verified to be large enough to contain the struct they belong
to, so a short response makes the read land past the end of the allocation.
handle_response() sizes entry->response purely from the netlink attribute
length (nla_len()) and only guards the leading handle read, so the daemon
can install a response as small as the kmalloc-8 object seen below. When
ipc_msg_send_request() then calls ipc_validate_msg() for a
KSMBD_EVENT_RPC_REQUEST, the cast to struct ksmbd_rpc_command reads
resp->payload_sz at offset 8 of an 8-byte allocation:
[ 3697.841381] ==================================================================
[ 3697.844099] BUG: KASAN: slab-out-of-bounds in ipc_msg_send_request+0x763/0x800
[ 3697.846604] Read of size 4 at addr ffff888105f95910 by task kworker/4:3/20682
[ 3697.849061]
[ 3697.849801] CPU: 4 UID: 0 PID: 20682 Comm: kworker/4:3 Not tainted 7.2.0-rc3-next-20260717-virtme #117 PREEMPT(lazy)
[ 3697.850077] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[ 3697.850303] Workqueue: ksmbd-io handle_ksmbd_work
[ 3697.850592] Call Trace:
[ 3697.850794] <TASK>
[ 3697.850952] __dump_stack+0x21/0x60
[ 3697.851239] dump_stack_lvl+0xc2/0x100
[ 3697.851528] print_address_description+0x77/0x200
[ 3697.851816] ? ipc_msg_send_request+0x763/0x800
[ 3697.852024] print_report+0x58/0x70
[ 3697.852316] kasan_report+0x117/0x150
[ 3697.852585] ? down_write+0x146/0x1f0
[ 3697.852809] ? ipc_msg_send_request+0x763/0x800
[ 3697.853082] ipc_msg_send_request+0x763/0x800
[ 3697.853385] ? __pfx_ipc_msg_send_request+0x10/0x10
[ 3697.853604] ? kasan_unpoison+0x48/0x70
[ 3697.853936] ? __pfx___up_read+0x10/0x10
[ 3697.854221] ksmbd_rpc_ioctl+0x380/0x520
[ 3697.854542] ? __pfx_ksmbd_rpc_ioctl+0x10/0x10
[ 3697.854757] ? kasan_unpoison+0x48/0x70
[ 3697.854962] ? copy_from_kernel_nofault+0x32c/0x4e0
[ 3697.855166] ? kasan_unpoison+0x48/0x70
[ 3697.855416] fsctl_pipe_transceive+0x139/0x7a0
[ 3697.855705] ? __pfx_copy_from_kernel_nofault+0x10/0x10
[ 3697.855937] ? __pfx_fsctl_pipe_transceive+0x10/0x10
[ 3697.856388] ? __sanitizer_cov_trace_switch+0x7b/0x140
[ 3697.856620] smb2_ioctl+0x1141/0x3420
[ 3697.856994] ? __pfx_smb2_ioctl+0x10/0x10
[ 3697.857182] ? get_smb2_cmd_val+0xe3/0x1c0
[ 3697.857655] handle_ksmbd_work+0x9ad/0x15e0
[ 3697.858034] ? __pfx_handle_ksmbd_work+0x10/0x10
[ 3697.858251] ? lock_release+0xf7/0x360
[ 3697.858466] ? process_scheduled_works+0x954/0x1600
[ 3697.858698] ? process_scheduled_works+0x954/0x1600
[ 3697.858905] process_scheduled_works+0xc22/0x1600
[ 3697.859368] ? __pfx_process_scheduled_works+0x10/0x10
[ 3697.859637] ? __pfx_assign_work+0x10/0x10
[ 3697.859896] ? lock_is_held_type+0x7b/0x110
[ 3697.860146] worker_thread+0x975/0xee0
[ 3697.860524] ? __pfx_do_raw_spin_lock+0x10/0x10
[ 3697.860830] ? __kthread_parkme+0x21e/0x260
[ 3697.861105] kthread+0x3a6/0x490
[ 3697.861423] ? __pfx_worker_thread+0x10/0x10
[ 3697.861643] ? __pfx_kthread+0x10/0x10
[ 3697.861878] ret_from_fork+0x55a/0xa20
[ 3697.862194] ? __pfx_ret_from_fork+0x10/0x10
[ 3697.862480] ? __pfx_kthread+0x10/0x10
[ 3697.862714] ret_from_fork_asm+0x1a/0x30
[ 3697.862965] </TASK>
[ 3697.863039]
[ 3697.938882] Allocated by task 20761:
[ 3697.940257] kasan_save_track+0x3e/0x80
[ 3697.941782] __kasan_kmalloc+0x72/0x90
[ 3697.943228] __kvmalloc_node_noprof+0x3e9/0x6a0
[ 3697.944948] handle_generic_event+0x59b/0x750
[ 3697.946592] genl_family_rcv_msg_doit+0x3d6/0x560
[ 3697.946977] genl_rcv_msg+0x67c/0x900
[ 3697.947224] netlink_rcv_skb+0x286/0x580
[ 3697.947488] genl_rcv+0x2d/0x80
[ 3
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Handle negative S1 walk levels in VNCR TLB size evaluation
Computing the effects of a TLB invalidation involves looking at
the size of the mapping cached by the TLB. For S1 mappings such as
VNCR, this is deducted from the combination of the base granule size
and the mapping level.
However, this implies that the S1 MMU is *on*. When the MMU is off,
we indicate this with the level being set to a "creative" value of
-127 (S1_MMU_DISABLED).
This ends-up being misinterpreted by pgshift_level_to_ttl() as it
doesn't handle negative levels at all (the level is immediately cast
to a u8 and only the bottom two bits considered), leading to an
invalidation size of 0. Not helpful.
Tidy-up pgshift_level_to_ttl() to handle these negative levels, and
ttl_to_size() to always return SZ_1G when no valid TTL is present.
This allows the removal of open-coded checks for similar situations.
Note that the check for a negative value not explicitely checking for
S1_MMU_DISABLED is deliberate, so that actual negative levels introduced
with LVA2 and D128 can take the same path if we ever support them. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Remove VM-wide VNCR mapping counter
The global VNCR mapping counter is used to decide whether an L1
provided VNCR page is mapped in L0 on any CPU at the point of
dealing with a TLB invalidation. It is incremented when a mapping
is made in the fixmap, and decremented when unmapped.
As it turns out, this tracking has several flaws:
- we are trying to invalidate TLBs, and the mapping is only an
opportunistic consequence of the TLB. Checking this counter to
decide whether a TLB needs to be invalidated may result in missed
invalidations.
- an L1 vcpu invalidating its own TLB (a very likely case) will not
succeed in invalidating the VNCR pseudo TLB because that page is
not mapped in L0 at this stage.
Given that this tracking fails at delivering the minimum guarantees
that are required and is only a performance optimisation, remove it
completely. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Correctly cap TLBI Range to the architural limit
TLB Invalidation by Range has a fairly powerful way of encoding pretty
large ranges in a small number of bits. This range can be based on an
arbitrary VA, which means it is pretty easy for a guest to generate an
overflow should the hypervisor be naive enough to add the range to the
base...
Make sure the range is capped to the limit dictated by the address bit
that determines the VA range. For an IPA invalidation, this is further
corrected down the line to ignore the upper range. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU
When emulating INVVPID, KVM executes INVVPID on the physical CPU using
vpid02 (instead of the L1 assigned VPID), after doing some validations
on the operands. However, it is possible that the physical CPU KVM
executes INVVPID on is different from the CPU L2 is running on.
For example, in the following scenario:
- L2 runs on CPU #1 and exits to L1 (vmx->nested.vmcs02.cpu=1)
- L1 migrates to CPU #2 and executes INVVPID
- KVM executes INVVPID on CPU #2
- L1 migrates back to CPU #1 and runs L2 (vmx->nested.vmcs02.cpu=1)
The TLB entries on CPU #1 are never invalidated, because INVVPID was
executed on CPU #2, and vmcs02 never ran on a different pCPU (i.e.
vmx_vcpu_load_vmcs() will *not* request KVM_REQ_TLB_FLUSH).
Ensure that INVVPID is being executed on the same pCPU that L2 last ran
on, and if not, fallback to clearing last_vpid=0 to trigger a full VPID
flush on the next nested VM-Enter (as KVM will detect L1 using a
different VPID for L2). If L2 ends up running on a different pCPU, KVM
will flush the TLB anyway through vmx_vcpu_load_vmcs(). |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: nVMX: Always flush vpid02 on first use
Make sure vpid02 is always flushed on first use by setting last_vpid=0
when allocating vpid02. nested_vmx_transition_tlb_flush() will always
detect a VPID change on first VM-Enter after VMXON, because VPID=0 in
vmcs12 is not allowed if L1 enables VPID.
This avoids using stale TLB entries from a previous lifetime of the
VPID, that might have been associated with a different vCPU (or a
completely different VM).
Note that last_vpid is already being initialized as 0 when the vCPU is
created, but it is not reset when vpid02 is freed on VMXOFF. Hence, the
problem can only occur if L1 does VMXOFF -> VMXON, runs an L2, and KVM
happens to reuse a VPID that has TLB entries on the physical CPU. |
| In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Fix uninitialized stack variable issue with dmsintc
Variable vector[] is declared on stack in function dmsintc_inject_irq()
and sometimes it is used without initialized. Here fix this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping
While VNCR TLB invalidation always occurs under the MMU lock,
vcpu_put() doesn't, while it unmaps the VNCR page.
The problem is that the invalidation evaluates vncr_tlb::cpu to
decide whether an unmapping needs to take place (cpu != -1) before
performing it. On the other hand, this_cpu_reset_vncr_fixmap()
unconditionally unmaps if L1_VNCR_MAPPED is set.
These two obviously can race, with a TOCTOU pattern on the TLBI
path, and a BUG_ON() on the vcpu_put() path. And the two can end-up
calling vncr_fixmap(-1), with extra lethal effects.
Move the reset of vncr_tlb::cpu to -1 to a common function, and make
this update atomic so that only a single thread can reset the field
and perform the corresponding unmap. The vcpu_put() still need to
unconditionally unmap the current VNCR to close another ugly race.
Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync
with the actual mapping, similar to L1_VNCR_MAPPED being set. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Fix memory corruption by not reinjecting CK machine checks
Channel-subsystem damage machine checks are for the host channel
subsystem. The guest channel subsystem is emulated in the userspace VMM.
There is no point in forwarding such machine checks into the guest.
This also simplifies the machine check reinjection and avoids kfree of a
stack variable as reported by sashiko. There might be still machine
checks that have the ck bit set with another bit (like instruction
damage), mask out the CK bit in s390_backup_mcck_info(), like the CP and
ED bits already are. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: Fix length check __import_wp_info()
struct kvm_hw_breakpoint::len is a __u64 that is fully controlled by user
space. This is then assigned to wp_info->len, which is an int. The bounds
check is done on the truncated value while the allocation uses the
untruncated one:
wp_info->len = bp_data->len;
[...]
if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE)
return -EINVAL;
wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT);
Use the validated value for the allocation as intended. Without this
fix userspace can trigger >4GB allocations which will fail and result
in a WARN due to MAX_PAGE_ORDER. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d0
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