| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: dlink: handle copy_thresh allocation failure
The driver did not handle failure of `netdev_alloc_skb_ip_align()`.
If the allocation failed, dereferencing `skb->protocol` could lead to
a NULL pointer dereference.
This patch tries to allocate `skb`. If the allocation fails, it falls
back to the normal path.
Tested-on: D-Link DGE-550T Rev-A3 |
| In the Linux kernel, the following vulnerability has been resolved:
i40e: add validation for ring_len param
The `ring_len` parameter provided by the virtual function (VF)
is assigned directly to the hardware memory context (HMC) without
any validation.
To address this, introduce an upper boundary check for both Tx and Rx
queue lengths. The maximum number of descriptors supported by the
hardware is 8k-32.
Additionally, enforce alignment constraints: Tx rings must be a multiple
of 8, and Rx rings must be a multiple of 32. |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: fix invalid accesses to ceph_connection_v1_info
There is a place where generic code in messenger.c is reading and
another place where it is writing to con->v1 union member without
checking that the union member is active (i.e. msgr1 is in use).
On 64-bit systems, con->v1.auth_retry overlaps with con->v2.out_iter,
so such a read is almost guaranteed to return a bogus value instead of
0 when msgr2 is in use. This ends up being fairly benign because the
side effect is just the invalidation of the authorizer and successive
fetching of new tickets.
con->v1.connect_seq overlaps with con->v2.conn_bufs and the fact that
it's being written to can cause more serious consequences, but luckily
it's not something that happens often. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()
syzbot reported the splat below without a repro.
In the splat, a single thread calling bt_accept_dequeue() freed sk
and touched it after that.
The root cause would be the racy l2cap_sock_cleanup_listen() call
added by the cited commit.
bt_accept_dequeue() is called under lock_sock() except for
l2cap_sock_release().
Two threads could see the same socket during the list iteration
in bt_accept_dequeue():
CPU1 CPU2 (close())
---- ----
sock_hold(sk) sock_hold(sk);
lock_sock(sk) <-- block close()
sock_put(sk)
bt_accept_unlink(sk)
sock_put(sk) <-- refcnt by bt_accept_enqueue()
release_sock(sk)
lock_sock(sk)
sock_put(sk)
bt_accept_unlink(sk)
sock_put(sk) <-- last refcnt
bt_accept_unlink(sk) <-- UAF
Depending on the timing, the other thread could show up in the
"Freed by task" part.
Let's call l2cap_sock_cleanup_listen() under lock_sock() in
l2cap_sock_release().
[0]:
BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115
Read of size 4 at addr ffff88803b7eb1c4 by task syz.5.3276/16995
CPU: 3 UID: 0 PID: 16995 Comm: syz.5.3276 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115
spin_lock_bh include/linux/spinlock.h:356 [inline]
release_sock+0x21/0x220 net/core/sock.c:3746
bt_accept_dequeue+0x505/0x600 net/bluetooth/af_bluetooth.c:312
l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1451
l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1425
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x3ff/0xb70 fs/file_table.c:468
task_work_run+0x14d/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2accf8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb6cb1378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000426fb RCX: 00007f2accf8ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f2acd1b7da0 R08: 0000000000000001 R09: 00000012b6cb166f
R10: 0000001b30e20000 R11: 0000000000000246 R12: 00007f2acd1b609c
R13: 00007f2acd1b6090 R14: ffffffffffffffff R15: 00007ffdb6cb1490
</TASK>
Allocated by task 5326:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4365 [inline]
__kmalloc_nopro
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
dm: Always split write BIOs to zoned device limits
Any zoned DM target that requires zone append emulation will use the
block layer zone write plugging. In such case, DM target drivers must
not split BIOs using dm_accept_partial_bio() as doing so can potentially
lead to deadlocks with queue freeze operations. Regular write operations
used to emulate zone append operations also cannot be split by the
target driver as that would result in an invalid writen sector value
return using the BIO sector.
In order for zoned DM target drivers to avoid such incorrect BIO
splitting, we must ensure that large BIOs are split before being passed
to the map() function of the target, thus guaranteeing that the
limits for the mapped device are not exceeded.
dm-crypt and dm-flakey are the only target drivers supporting zoned
devices and using dm_accept_partial_bio().
In the case of dm-crypt, this function is used to split BIOs to the
internal max_write_size limit (which will be suppressed in a different
patch). However, since crypt_alloc_buffer() uses a bioset allowing only
up to BIO_MAX_VECS (256) vectors in a BIO. The dm-crypt device
max_segments limit, which is not set and so default to BLK_MAX_SEGMENTS
(128), must thus be respected and write BIOs split accordingly.
In the case of dm-flakey, since zone append emulation is not required,
the block layer zone write plugging is not used and no splitting of BIOs
required.
Modify the function dm_zone_bio_needs_split() to use the block layer
helper function bio_needs_zone_write_plugging() to force a call to
bio_split_to_limits() in dm_split_and_process_bio(). This allows DM
target drivers to avoid using dm_accept_partial_bio() for write
operations on zoned DM devices. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix race in do_task() when draining
When do_task() exhausts its iteration budget (!ret), it sets the state
to TASK_STATE_IDLE to reschedule, without a secondary check on the
current task->state. This can overwrite the TASK_STATE_DRAINING state
set by a concurrent call to rxe_cleanup_task() or rxe_disable_task().
While state changes are protected by a spinlock, both rxe_cleanup_task()
and rxe_disable_task() release the lock while waiting for the task to
finish draining in the while(!is_done(task)) loop. The race occurs if
do_task() hits its iteration limit and acquires the lock in this window.
The cleanup logic may then proceed while the task incorrectly
reschedules itself, leading to a potential use-after-free.
This bug was introduced during the migration from tasklets to workqueues,
where the special handling for the draining case was lost.
Fix this by restoring the original pre-migration behavior. If the state is
TASK_STATE_DRAINING when iterations are exhausted, set cont to 1 to
force a new loop iteration. This allows the task to finish its work, so
that a subsequent iteration can reach the switch statement and correctly
transition the state to TASK_STATE_DRAINED, stopping the task as intended. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait()
There is a bug observed when rtw89_core_tx_kick_off_and_wait() tries to
access already freed skb_data:
BUG: KFENCE: use-after-free write in rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110
CPU: 6 UID: 0 PID: 41377 Comm: kworker/u64:24 Not tainted 6.17.0-rc1+ #1 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS edk2-20250523-14.fc42 05/23/2025
Workqueue: events_unbound cfg80211_wiphy_work [cfg80211]
Use-after-free write at 0x0000000020309d9d (in kfence-#251):
rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110
rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.h:141
rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
process_one_work kernel/workqueue.c:3241
worker_thread kernel/workqueue.c:3400
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
kfence-#251: 0x0000000056e2393d-0x000000009943cb62, size=232, cache=skbuff_head_cache
allocated by task 41377 on cpu 6 at 77869.159548s (0.009551s ago):
__alloc_skb net/core/skbuff.c:659
__netdev_alloc_skb net/core/skbuff.c:734
ieee80211_nullfunc_get net/mac80211/tx.c:5844
rtw89_core_send_nullfunc drivers/net/wireless/realtek/rtw89/core.c:3431
rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.c:3194
rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
process_one_work kernel/workqueue.c:3241
worker_thread kernel/workqueue.c:3400
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
freed by task 1045 on cpu 9 at 77869.168393s (0.001557s ago):
ieee80211_tx_status_skb net/mac80211/status.c:1117
rtw89_pci_release_txwd_skb drivers/net/wireless/realtek/rtw89/pci.c:564
rtw89_pci_release_tx_skbs.isra.0 drivers/net/wireless/realtek/rtw89/pci.c:651
rtw89_pci_release_tx drivers/net/wireless/realtek/rtw89/pci.c:676
rtw89_pci_napi_poll drivers/net/wireless/realtek/rtw89/pci.c:4238
__napi_poll net/core/dev.c:7495
net_rx_action net/core/dev.c:7557 net/core/dev.c:7684
handle_softirqs kernel/softirq.c:580
do_softirq.part.0 kernel/softirq.c:480
__local_bh_enable_ip kernel/softirq.c:407
rtw89_pci_interrupt_threadfn drivers/net/wireless/realtek/rtw89/pci.c:927
irq_thread_fn kernel/irq/manage.c:1133
irq_thread kernel/irq/manage.c:1257
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
It is a consequence of a race between the waiting and the signaling side
of the completion:
Waiting thread Completing thread
rtw89_core_tx_kick_off_and_wait()
rcu_assign_pointer(skb_data->wait, wait)
/* start waiting */
wait_for_completion_timeout()
rtw89_pci_tx_status()
rtw89_core_tx_wait_complete()
rcu_read_lock()
/* signals completion and
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix incorrect io_kiocb reference in io_link_skb
In io_link_skb function, there is a bug where prev_notif is incorrectly
assigned using 'nd' instead of 'prev_nd'. This causes the context
validation check to compare the current notification with itself instead
of comparing it with the previous notification.
Fix by using the correct prev_nd parameter when obtaining prev_notif. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request().
syzbot reported the splat below in tcp_conn_request(). [0]
If a listener is close()d while a TFO socket is being processed in
tcp_conn_request(), inet_csk_reqsk_queue_add() does not set reqsk->sk
and calls inet_child_forget(), which calls tcp_disconnect() for the
TFO socket.
After the cited commit, tcp_disconnect() calls reqsk_fastopen_remove(),
where reqsk_put() is called due to !reqsk->sk.
Then, reqsk_fastopen_remove() in tcp_conn_request() decrements the
last req->rsk_refcnt and frees reqsk, and __reqsk_free() at the
drop_and_free label causes the refcount underflow for the listener
and double-free of the reqsk.
Let's remove reqsk_fastopen_remove() in tcp_conn_request().
Note that other callers make sure tp->fastopen_rsk is not NULL.
[0]:
refcount_t: underflow; use-after-free.
WARNING: CPU: 12 PID: 5563 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28)
Modules linked in:
CPU: 12 UID: 0 PID: 5563 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:refcount_warn_saturate (lib/refcount.c:28)
Code: ab e8 8e b4 98 ff 0f 0b c3 cc cc cc cc cc 80 3d a4 e4 d6 01 00 75 9c c6 05 9b e4 d6 01 01 48 c7 c7 e8 df fb ab e8 6a b4 98 ff <0f> 0b e9 03 5b 76 00 cc 80 3d 7d e4 d6 01 00 0f 85 74 ff ff ff c6
RSP: 0018:ffffa79fc0304a98 EFLAGS: 00010246
RAX: d83af4db1c6b3900 RBX: ffff9f65c7a69020 RCX: d83af4db1c6b3900
RDX: 0000000000000000 RSI: 00000000ffff7fff RDI: ffffffffac78a280
RBP: 000000009d781b60 R08: 0000000000007fff R09: ffffffffac6ca280
R10: 0000000000017ffd R11: 0000000000000004 R12: ffff9f65c7b4f100
R13: ffff9f65c7d23c00 R14: ffff9f65c7d26000 R15: ffff9f65c7a64ef8
FS: 00007f9f962176c0(0000) GS:ffff9f65fcf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000180 CR3: 000000000dbbe006 CR4: 0000000000372ef0
Call Trace:
<IRQ>
tcp_conn_request (./include/linux/refcount.h:400 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/sock.h:1965 ./include/net/request_sock.h:131 net/ipv4/tcp_input.c:7301)
tcp_rcv_state_process (net/ipv4/tcp_input.c:6708)
tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1670)
tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1906)
ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438)
ip6_input (net/ipv6/ip6_input.c:500)
ipv6_rcv (net/ipv6/ip6_input.c:311)
__netif_receive_skb (net/core/dev.c:6104)
process_backlog (net/core/dev.c:6456)
__napi_poll (net/core/dev.c:7506)
net_rx_action (net/core/dev.c:7569 net/core/dev.c:7696)
handle_softirqs (kernel/softirq.c:579)
do_softirq (kernel/softirq.c:480)
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6}
Cilium has a BPF egress gateway feature which forces outgoing K8s Pod
traffic to pass through dedicated egress gateways which then SNAT the
traffic in order to interact with stable IPs outside the cluster.
The traffic is directed to the gateway via vxlan tunnel in collect md
mode. A recent BPF change utilized the bpf_redirect_neigh() helper to
forward packets after the arrival and decap on vxlan, which turned out
over time that the kmalloc-256 slab usage in kernel was ever-increasing.
The issue was that vxlan allocates the metadata_dst object and attaches
it through a fake dst entry to the skb. The latter was never released
though given bpf_redirect_neigh() was merely setting the new dst entry
via skb_dst_set() without dropping an existing one first. |
| In the Linux kernel, the following vulnerability has been resolved:
net/ip6_tunnel: Prevent perpetual tunnel growth
Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too.
While ipv4 tunnel headroom adjustment growth was limited in
commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"),
ipv6 tunnel yet increases the headroom without any ceiling.
Reflect ipv4 tunnel headroom adjustment limit on ipv6 version.
Credits to Francesco Ruggeri, who was originally debugging this issue
and wrote local Arista-specific patch and a reproducer. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_objref: validate objref and objrefmap expressions
Referencing a synproxy stateful object from OUTPUT hook causes kernel
crash due to infinite recursive calls:
BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12)
[...]
Call Trace:
__find_rr_leaf+0x99/0x230
fib6_table_lookup+0x13b/0x2d0
ip6_pol_route+0xa4/0x400
fib6_rule_lookup+0x156/0x240
ip6_route_output_flags+0xc6/0x150
__nf_ip6_route+0x23/0x50
synproxy_send_tcp_ipv6+0x106/0x200
synproxy_send_client_synack_ipv6+0x1aa/0x1f0
nft_synproxy_do_eval+0x263/0x310
nft_do_chain+0x5a8/0x5f0 [nf_tables
nft_do_chain_inet+0x98/0x110
nf_hook_slow+0x43/0xc0
__ip6_local_out+0xf0/0x170
ip6_local_out+0x17/0x70
synproxy_send_tcp_ipv6+0x1a2/0x200
synproxy_send_client_synack_ipv6+0x1aa/0x1f0
[...]
Implement objref and objrefmap expression validate functions.
Currently, only NFT_OBJECT_SYNPROXY object type requires validation.
This will also handle a jump to a chain using a synproxy object from the
OUTPUT hook.
Now when trying to reference a synproxy object in the OUTPUT hook, nft
will produce the following error:
synproxy_crash.nft: Error: Could not process rule: Operation not supported
synproxy name mysynproxy
^^^^^^^^^^^^^^^^^^^^^^^^ |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet-fc: move lsop put work to nvmet_fc_ls_req_op
It’s possible for more than one async command to be in flight from
__nvmet_fc_send_ls_req. For each command, a tgtport reference is taken.
In the current code, only one put work item is queued at a time, which
results in a leaked reference.
To fix this, move the work item to the nvmet_fc_ls_req_op struct, which
already tracks all resources related to the command. |
| In the Linux kernel, the following vulnerability has been resolved:
kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
The usage of task_lock(tsk->group_leader) in sys_prlimit64()->do_prlimit()
path is very broken.
sys_prlimit64() does get_task_struct(tsk) but this only protects task_struct
itself. If tsk != current and tsk is not a leader, this process can exit/exec
and task_lock(tsk->group_leader) may use the already freed task_struct.
Another problem is that sys_prlimit64() can race with mt-exec which changes
->group_leader. In this case do_prlimit() may take the wrong lock, or (worse)
->group_leader may change between task_lock() and task_unlock().
Change sys_prlimit64() to take tasklist_lock when necessary. This is not
nice, but I don't see a better fix for -stable. |
| In the Linux kernel, the following vulnerability has been resolved:
xsk: Harden userspace-supplied xdp_desc validation
Turned out certain clearly invalid values passed in xdp_desc from
userspace can pass xp_{,un}aligned_validate_desc() and then lead
to UBs or just invalid frames to be queued for xmit.
desc->len close to ``U32_MAX`` with a non-zero pool->tx_metadata_len
can cause positive integer overflow and wraparound, the same way low
enough desc->addr with a non-zero pool->tx_metadata_len can cause
negative integer overflow. Both scenarios can then pass the
validation successfully.
This doesn't happen with valid XSk applications, but can be used
to perform attacks.
Always promote desc->len to ``u64`` first to exclude positive
overflows of it. Use explicit check_{add,sub}_overflow() when
validating desc->addr (which is ``u64`` already).
bloat-o-meter reports a little growth of the code size:
add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44)
Function old new delta
xskq_cons_peek_desc 299 330 +31
xsk_tx_peek_release_desc_batch 973 1002 +29
xsk_generic_xmit 3148 3132 -16
but hopefully this doesn't hurt the performance much. |
| In the Linux kernel, the following vulnerability has been resolved:
uio_hv_generic: Let userspace take care of interrupt mask
Remove the logic to set interrupt mask by default in uio_hv_generic
driver as the interrupt mask value is supposed to be controlled
completely by the user space. If the mask bit gets changed
by the driver, concurrently with user mode operating on the ring,
the mask bit may be set when it is supposed to be clear, and the
user-mode driver will miss an interrupt which will cause a hang.
For eg- when the driver sets inbound ring buffer interrupt mask to 1,
the host does not interrupt the guest on the UIO VMBus channel.
However, setting the mask does not prevent the host from putting a
message in the inbound ring buffer. So let’s assume that happens,
the host puts a message into the ring buffer but does not interrupt.
Subsequently, the user space code in the guest sets the inbound ring
buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”.
User space code then calls pread() to wait for an interrupt.
Then one of two things happens:
* The host never sends another message. So the pread() waits forever.
* The host does send another message. But because there’s already a
message in the ring buffer, it doesn’t generate an interrupt.
This is the correct behavior, because the host should only send an
interrupt when the inbound ring buffer transitions from empty to
not-empty. Adding an additional message to a ring buffer that is not
empty is not supposed to generate an interrupt on the guest.
Since the guest is waiting in pread() and not removing messages from
the ring buffer, the pread() waits forever.
This could be easily reproduced in hv_fcopy_uio_daemon if we delay
setting interrupt mask to 0.
Similarly if hv_uio_channel_cb() sets the interrupt_mask to 1,
there’s a race condition. Once user space empties the inbound ring
buffer, but before user space sets interrupt_mask to 0, the host could
put another message in the ring buffer but it wouldn’t interrupt.
Then the next pread() would hang.
Fix these by removing all instances where interrupt_mask is changed,
while keeping the one in set_event() unchanged to enable userspace
control the interrupt mask by writing 0/1 to /dev/uioX. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O
When completing emulation of instruction that generated a userspace exit
for I/O, don't recheck L1 intercepts as KVM has already finished that
phase of instruction execution, i.e. has already committed to allowing L2
to perform I/O. If L1 (or host userspace) modifies the I/O permission
bitmaps during the exit to userspace, KVM will treat the access as being
intercepted despite already having emulated the I/O access.
Pivot on EMULTYPE_NO_DECODE to detect that KVM is completing emulation.
Of the three users of EMULTYPE_NO_DECODE, only complete_emulated_io() (the
intended "recipient") can reach the code in question. gp_interception()'s
use is mutually exclusive with is_guest_mode(), and
complete_emulated_insn_gp() unconditionally pairs EMULTYPE_NO_DECODE with
EMULTYPE_SKIP.
The bad behavior was detected by a syzkaller program that toggles port I/O
interception during the userspace I/O exit, ultimately resulting in a WARN
on vcpu->arch.pio.count being non-zero due to KVM no completing emulation
of the I/O instruction.
WARNING: CPU: 23 PID: 1083 at arch/x86/kvm/x86.c:8039 emulator_pio_in_out+0x154/0x170 [kvm]
Modules linked in: kvm_intel kvm irqbypass
CPU: 23 UID: 1000 PID: 1083 Comm: repro Not tainted 6.16.0-rc5-c1610d2d66b1-next-vm #74 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:emulator_pio_in_out+0x154/0x170 [kvm]
PKRU: 55555554
Call Trace:
<TASK>
kvm_fast_pio+0xd6/0x1d0 [kvm]
vmx_handle_exit+0x149/0x610 [kvm_intel]
kvm_arch_vcpu_ioctl_run+0xda8/0x1ac0 [kvm]
kvm_vcpu_ioctl+0x244/0x8c0 [kvm]
__x64_sys_ioctl+0x8a/0xd0
do_syscall_64+0x5d/0xc60
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
[hverkuil: fix typo in Subject: tunner -> tuner] |
| In the Linux kernel, the following vulnerability has been resolved:
i40e: fix validation of VF state in get resources
VF state I40E_VF_STATE_ACTIVE is not the only state in which
VF is actually active so it should not be used to determine
if a VF is allowed to obtain resources.
Use I40E_VF_STATE_RESOURCES_LOADED that is set only in
i40e_vc_get_vf_resources_msg() and cleared during reset. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd/pgtbl: Fix possible race while increase page table level
The AMD IOMMU host page table implementation supports dynamic page table levels
(up to 6 levels), starting with a 3-level configuration that expands based on
IOVA address. The kernel maintains a root pointer and current page table level
to enable proper page table walks in alloc_pte()/fetch_pte() operations.
The IOMMU IOVA allocator initially starts with 32-bit address and onces its
exhuasted it switches to 64-bit address (max address is determined based
on IOMMU and device DMA capability). To support larger IOVA, AMD IOMMU
driver increases page table level.
But in unmap path (iommu_v1_unmap_pages()), fetch_pte() reads
pgtable->[root/mode] without lock. So its possible that in exteme corner case,
when increase_address_space() is updating pgtable->[root/mode], fetch_pte()
reads wrong page table level (pgtable->mode). It does compare the value with
level encoded in page table and returns NULL. This will result is
iommu_unmap ops to fail and upper layer may retry/log WARN_ON.
CPU 0 CPU 1
------ ------
map pages unmap pages
alloc_pte() -> increase_address_space() iommu_v1_unmap_pages() -> fetch_pte()
pgtable->root = pte (new root value)
READ pgtable->[mode/root]
Reads new root, old mode
Updates mode (pgtable->mode += 1)
Since Page table level updates are infrequent and already synchronized with a
spinlock, implement seqcount to enable lock-free read operations on the read path. |
