| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
jfs: Prevent copying of nlink with value 0 from disk inode
syzbot report a deadlock in diFree. [1]
When calling "ioctl$LOOP_SET_STATUS64", the offset value passed in is 4,
which does not match the mounted loop device, causing the mapping of the
mounted loop device to be invalidated.
When creating the directory and creating the inode of iag in diReadSpecial(),
read the page of fixed disk inode (AIT) in raw mode in read_metapage(), the
metapage data it returns is corrupted, which causes the nlink value of 0 to be
assigned to the iag inode when executing copy_from_dinode(), which ultimately
causes a deadlock when entering diFree().
To avoid this, first check the nlink value of dinode before setting iag inode.
[1]
WARNING: possible recursive locking detected
6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted
--------------------------------------------
syz-executor301/5309 is trying to acquire lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889
but task is already holding lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(imap->im_aglock[index]));
lock(&(imap->im_aglock[index]));
*** DEADLOCK ***
May be due to missing lock nesting notation
5 locks held by syz-executor301/5309:
#0: ffff8880422a4420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
#1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
#1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:4026
#2: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2460 [inline]
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocAG+0x4b7/0x1e50 fs/jfs/jfs_imap.c:1669
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2477 [inline]
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocAG+0x869/0x1e50 fs/jfs/jfs_imap.c:1669
stack backtrace:
CPU: 0 UID: 0 PID: 5309 Comm: syz-executor301 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
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+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
check_deadlock kernel/locking/lockdep.c:3089 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889
jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156
evict+0x4e8/0x9b0 fs/inode.c:725
diFreeSpecial fs/jfs/jfs_imap.c:552 [inline]
duplicateIXtree+0x3c6/0x550 fs/jfs/jfs_imap.c:3022
diNewIAG fs/jfs/jfs_imap.c:2597 [inline]
diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
diAllocAG+0x17dc/0x1e50 fs/jfs/jfs_imap.c:1669
diAlloc+0x1d2/0x1630 fs/jfs/jfs_imap.c:1590
ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x1c5/0xba0 fs/jfs/namei.c:225
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
do_mkdirat+0x264/0x3a0 fs/namei.c:4280
__do_sys_mkdirat fs/namei.c:4295 [inline]
__se_sys_mkdirat fs/namei.c:4293 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
do_syscall_x64 arch/x86/en
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "smb: client: fix TCP timers deadlock after rmmod"
This reverts commit e9f2517a3e18a54a3943c098d2226b245d488801.
Commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after
rmmod") is intended to fix a null-ptr-deref in LOCKDEP, which is
mentioned as CVE-2024-54680, but is actually did not fix anything;
The issue can be reproduced on top of it. [0]
Also, it reverted the change by commit ef7134c7fc48 ("smb: client:
Fix use-after-free of network namespace.") and introduced a real
issue by reviving the kernel TCP socket.
When a reconnect happens for a CIFS connection, the socket state
transitions to FIN_WAIT_1. Then, inet_csk_clear_xmit_timers_sync()
in tcp_close() stops all timers for the socket.
If an incoming FIN packet is lost, the socket will stay at FIN_WAIT_1
forever, and such sockets could be leaked up to net.ipv4.tcp_max_orphans.
Usually, FIN can be retransmitted by the peer, but if the peer aborts
the connection, the issue comes into reality.
I warned about this privately by pointing out the exact report [1],
but the bogus fix was finally merged.
So, we should not stop the timers to finally kill the connection on
our side in that case, meaning we must not use a kernel socket for
TCP whose sk->sk_net_refcnt is 0.
The kernel socket does not have a reference to its netns to make it
possible to tear down netns without cleaning up every resource in it.
For example, tunnel devices use a UDP socket internally, but we can
destroy netns without removing such devices and let it complete
during exit. Otherwise, netns would be leaked when the last application
died.
However, this is problematic for TCP sockets because TCP has timers to
close the connection gracefully even after the socket is close()d. The
lifetime of the socket and its netns is different from the lifetime of
the underlying connection.
If the socket user does not maintain the netns lifetime, the timer could
be fired after the socket is close()d and its netns is freed up, resulting
in use-after-free.
Actually, we have seen so many similar issues and converted such sockets
to have a reference to netns.
That's why I converted the CIFS client socket to have a reference to
netns (sk->sk_net_refcnt == 1), which is somehow mentioned as out-of-scope
of CIFS and technically wrong in e9f2517a3e18, but **is in-scope and right
fix**.
Regarding the LOCKDEP issue, we can prevent the module unload by
bumping the module refcount when switching the LOCKDDEP key in
sock_lock_init_class_and_name(). [2]
For a while, let's revert the bogus fix.
Note that now we can use sk_net_refcnt_upgrade() for the socket
conversion, but I'll do so later separately to make backport easy. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "arm64: dts: qcom: sdm845: Affirm IDR0.CCTW on apps_smmu"
There are reports that the pagetable walker cache coherency is not a
given across the spectrum of SDM845/850 devices, leading to lock-ups
and resets. It works fine on some devices (like the Dragonboard 845c,
but not so much on the Lenovo Yoga C630).
This unfortunately looks like a fluke in firmware development, where
likely somewhere in the vast hypervisor stack, a change to accommodate
for this was only introduced after the initial software release (which
often serves as a baseline for products).
Revert the change to avoid additional guesswork around crashes.
This reverts commit 6b31a9744b8726c69bb0af290f8475a368a4b805. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/hmm: Don't dereference struct page pointers without notifier lock
The pnfs that we obtain from hmm_range_fault() point to pages that
we don't have a reference on, and the guarantee that they are still
in the cpu page-tables is that the notifier lock must be held and the
notifier seqno is still valid.
So while building the sg table and marking the pages accesses / dirty
we need to hold this lock with a validated seqno.
However, the lock is reclaim tainted which makes
sg_alloc_table_from_pages_segment() unusable, since it internally
allocates memory.
Instead build the sg-table manually. For the non-iommu case
this might lead to fewer coalesces, but if that's a problem it can
be fixed up later in the resource cursor code. For the iommu case,
the whole sg-table may still be coalesced to a single contigous
device va region.
This avoids marking pages that we don't own dirty and accessed, and
it also avoid dereferencing struct pages that we don't own.
v2:
- Use assert to check whether hmm pfns are valid (Matthew Auld)
- Take into account that large pages may cross range boundaries
(Matthew Auld)
v3:
- Don't unnecessarily check for a non-freed sg-table. (Matthew Auld)
- Add a missing up_read() in an error path. (Matthew Auld)
(cherry picked from commit ea3e66d280ce2576664a862693d1da8fd324c317) |
| In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix a deadlock when recovering state on a sillyrenamed file
If the file is sillyrenamed, and slated for delete on close, it is
possible for a server reboot to triggeer an open reclaim, with can again
race with the application call to close(). When that happens, the call
to put_nfs_open_context() can trigger a synchronous delegreturn call
which deadlocks because it is not marked as privileged.
Instead, ensure that the call to nfs4_inode_return_delegation_on_close()
catches the delegreturn, and schedules it asynchronously. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix softlockup in arena_map_free on 64k page kernel
On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y,
arena_htab tests cause a segmentation fault and soft lockup.
The same failure is not observed with 4k pages on aarch64.
It turns out arena_map_free() is calling
apply_to_existing_page_range() with the address returned by
bpf_arena_get_kern_vm_start(). If this address is not page-aligned
the code ends up calling apply_to_pte_range() with that unaligned
address causing soft lockup.
Fix it by round up GUARD_SZ to PAGE_SIZE << 1 so that the
division by 2 in bpf_arena_get_kern_vm_start() returns
a page-aligned value. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface()
The documentation for usb_driver_claim_interface() says that "the
device lock" is needed when the function is called from places other
than probe(). This appears to be the lock for the USB interface
device. The Mediatek btusb code gets called via this path:
Workqueue: hci0 hci_power_on [bluetooth]
Call trace:
usb_driver_claim_interface
btusb_mtk_claim_iso_intf
btusb_mtk_setup
hci_dev_open_sync
hci_power_on
process_scheduled_works
worker_thread
kthread
With the above call trace the device lock hasn't been claimed. Claim
it.
Without this fix, we'd sometimes see the error "Failed to claim iso
interface". Sometimes we'd even see worse errors, like a NULL pointer
dereference (where `intf->dev.driver` was NULL) with a trace like:
Call trace:
usb_suspend_both
usb_runtime_suspend
__rpm_callback
rpm_suspend
pm_runtime_work
process_scheduled_works
Both errors appear to be fixed with the proper locking. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc, afs: Fix peer hash locking vs RCU callback
In its address list, afs now retains pointers to and refs on one or more
rxrpc_peer objects. The address list is freed under RCU and at this time,
it puts the refs on those peers.
Now, when an rxrpc_peer object runs out of refs, it gets removed from the
peer hash table and, for that, rxrpc has to take a spinlock. However, it
is now being called from afs's RCU cleanup, which takes place in BH
context - but it is just taking an ordinary spinlock.
The put may also be called from non-BH context, and so there exists the
possibility of deadlock if the BH-based RCU cleanup happens whilst the hash
spinlock is held. This led to the attached lockdep complaint.
Fix this by changing spinlocks of rxnet->peer_hash_lock back to
BH-disabling locks.
================================
WARNING: inconsistent lock state
6.13.0-rc5-build2+ #1223 Tainted: G E
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff88810babe228 (&rxnet->peer_hash_lock){+.?.}-{3:3}, at: rxrpc_put_peer+0xcb/0x180
{SOFTIRQ-ON-W} state was registered at:
mark_usage+0x164/0x180
__lock_acquire+0x544/0x990
lock_acquire.part.0+0x103/0x280
_raw_spin_lock+0x2f/0x40
rxrpc_peer_keepalive_worker+0x144/0x440
process_one_work+0x486/0x7c0
process_scheduled_works+0x73/0x90
worker_thread+0x1c8/0x2a0
kthread+0x19b/0x1b0
ret_from_fork+0x24/0x40
ret_from_fork_asm+0x1a/0x30
irq event stamp: 972402
hardirqs last enabled at (972402): [<ffffffff8244360e>] _raw_spin_unlock_irqrestore+0x2e/0x50
hardirqs last disabled at (972401): [<ffffffff82443328>] _raw_spin_lock_irqsave+0x18/0x60
softirqs last enabled at (972300): [<ffffffff810ffbbe>] handle_softirqs+0x3ee/0x430
softirqs last disabled at (972313): [<ffffffff810ffc54>] __irq_exit_rcu+0x44/0x110
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&rxnet->peer_hash_lock);
<Interrupt>
lock(&rxnet->peer_hash_lock);
*** DEADLOCK ***
1 lock held by swapper/1/0:
#0: ffffffff83576be0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x7/0x30
stack backtrace:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G E 6.13.0-rc5-build2+ #1223
Tainted: [E]=UNSIGNED_MODULE
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
<IRQ>
dump_stack_lvl+0x57/0x80
print_usage_bug.part.0+0x227/0x240
valid_state+0x53/0x70
mark_lock_irq+0xa5/0x2f0
mark_lock+0xf7/0x170
mark_usage+0xe1/0x180
__lock_acquire+0x544/0x990
lock_acquire.part.0+0x103/0x280
_raw_spin_lock+0x2f/0x40
rxrpc_put_peer+0xcb/0x180
afs_free_addrlist+0x46/0x90 [kafs]
rcu_do_batch+0x2d2/0x640
rcu_core+0x2f7/0x350
handle_softirqs+0x1ee/0x430
__irq_exit_rcu+0x44/0x110
irq_exit_rcu+0xa/0x30
sysvec_apic_timer_interrupt+0x7f/0xa0
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: correct handling of extreme memory squeeze
Testing with iperf3 using the "pasta" protocol splicer has revealed
a problem in the way tcp handles window advertising in extreme memory
squeeze situations.
Under memory pressure, a socket endpoint may temporarily advertise
a zero-sized window, but this is not stored as part of the socket data.
The reasoning behind this is that it is considered a temporary setting
which shouldn't influence any further calculations.
However, if we happen to stall at an unfortunate value of the current
window size, the algorithm selecting a new value will consistently fail
to advertise a non-zero window once we have freed up enough memory.
This means that this side's notion of the current window size is
different from the one last advertised to the peer, causing the latter
to not send any data to resolve the sitution.
The problem occurs on the iperf3 server side, and the socket in question
is a completely regular socket with the default settings for the
fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket.
The following excerpt of a logging session, with own comments added,
shows more in detail what is happening:
// tcp_v4_rcv(->)
// tcp_rcv_established(->)
[5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ====
[5201<->39222]: tcp_data_queue(->)
[5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0]
[OFO queue: gap: 65480, len: 0]
[5201<->39222]: tcp_data_queue(<-)
[5201<->39222]: __tcp_transmit_skb(->)
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: tcp_select_window(->)
[5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
returning 0
[5201<->39222]: tcp_select_window(<-)
[5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160
[5201<->39222]: [__tcp_transmit_skb(<-)
[5201<->39222]: tcp_rcv_established(<-)
[5201<->39222]: tcp_v4_rcv(<-)
// Receive queue is at 85 buffers and we are out of memory.
// We drop the incoming buffer, although it is in sequence, and decide
// to send an advertisement with a window of zero.
// We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means
// we unconditionally shrink the window.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0]
returning 6104 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// After each read, the algorithm for calculating the new receive
// window in __tcp_cleanup_rbuf() finds it is too small to advertise
// or to update tp->rcv_wnd.
// Meanwhile, the peer thinks the window is zero, and will not send
// any more data to trigger an update from the interrupt mode side.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_n
---truncated--- |
| [This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
To manage the system, sysctl and platform operations are used by the
control domain or a possible Xenstore domain. Some of these operations
may not be executed in parallel, so a system-wide lock each is used.
The way those locks are acquired is, however, not providing any fairness.
Furthermore, with XSM/Flask in use, the lock acquire will, for some
operations, occur ahead of any permission checking.
The sysctl issue is CVE-2026-62426.
The platform-op issue is CVE-2026-62427. |
| A denial of service vulnerability due to a deadlock was found in sctp_auto_asconf_init in net/sctp/socket.c in the Linux kernel’s SCTP subsystem. This flaw allows guests with local user privileges to trigger a deadlock and potentially crash the system. |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix queue freeze vs limits lock order in sysfs store methods
queue_attr_store() always freezes a device queue before calling the
attribute store operation. For attributes that control queue limits, the
store operation will also lock the queue limits with a call to
queue_limits_start_update(). However, some drivers (e.g. SCSI sd) may
need to issue commands to a device to obtain limit values from the
hardware with the queue limits locked. This creates a potential ABBA
deadlock situation if a user attempts to modify a limit (thus freezing
the device queue) while the device driver starts a revalidation of the
device queue limits.
Avoid such deadlock by not freezing the queue before calling the
->store_limit() method in struct queue_sysfs_entry and instead use the
queue_limits_commit_update_frozen helper to freeze the queue after taking
the limits lock.
This also removes taking the sysfs lock for the store_limit method as
it doesn't protect anything here, but creates even more nesting.
Hopefully it will go away from the actual sysfs methods entirely soon.
(commit log adapted from a similar patch from Damien Le Moal) |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: use chan timer to close channels in cleanup_listen()
l2cap_chan_close() removes the channel from conn->chan_l, which
must be done under conn->lock. cleanup_listen() runs under the
parent sk_lock, so acquiring conn->lock would invert the
established conn->lock -> chan->lock -> sk_lock order.
Instead of calling l2cap_chan_close() directly, schedule
l2cap_chan_timeout with delay 0 to close the channel
asynchronously. The timeout handler already acquires conn->lock
and chan->lock in the correct order.
The timer is only armed when chan->conn is still set: if it is
already NULL, l2cap_conn_del() has already processed this channel
(l2cap_chan_del + l2cap_sock_teardown_cb + l2cap_sock_close_cb),
so there is nothing left to do. If l2cap_conn_del() races in
after the timer is armed, __clear_chan_timer() inside
l2cap_chan_del() cancels it; if the timer has already fired, the
handler returns harmlessly because chan->conn was cleared. |
| The USB CDC-NCM device class (subsys/usb/device_next/class/usbd_cdc_ncm.c) ignores the return value of usbd_ep_enqueue() in its ethernet transmit callback cdc_ncm_send(). When the enqueue fails, the function still calls k_sem_take(&data->sync_sem, K_FOREVER), blocking on a completion semaphore that is only ever signaled from the bulk-IN transfer-completion callback. Because nothing was enqueued, that callback never fires and the calling thread — a shared network traffic-class TX thread — deadlocks permanently while holding the interface TX lock, halting transmission until reboot (and leaking the transmit buffer).
The enqueue fails under conditions controlled by the attached USB host: usbd_ep_enqueue() returns -EPERM whenever the bus is suspended (a standard, persistent host operation), and the underlying udc_ep_enqueue() returns -EPERM/-ENODEV on disconnect, bus reset, or endpoint disable. The cdc_ncm_send() guard only checks the DATA_IFACE_ENABLED and IFACE_UP flags, not the suspended state, so a packet transmitted while the host holds the bus suspended reaches the failing enqueue and deadlocks the TX path.
The realistic trigger is a bus suspend that occurs while the exported network interface is active and has traffic to send — host sleep, USB selective/auto-suspend, or hub power management — after which any device-originated packet deadlocks the path, recoverable only by reboot. The impact is a persistent loss of the virtual network connection between the host's NCM interface and the Zephyr device; because the deadlocked thread is a shared traffic-class TX thread, egress on other network interfaces can stall as well. There is no memory corruption or information disclosure.
The defect was introduced with the CDC-NCM driver and shipped in releases through v4.4.0; it is fixed by checking the usbd_ep_enqueue() return value and freeing the buffer before the blocking wait. |
| In the Linux kernel, the following vulnerability has been resolved:
debugobjects: Don't call fill_pool() in early boot hardirq context
When booting a debug PREEMPT_RT kernel on an ARM64 system, a "inconsistent
{HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage" lockdep warning message was
reported to the console.
During early boot, interrupts are enabled before the scheduler is
enabled. In this window (before SYSTEM_SCHEDULING is set) interrupts can
fire and in the hard interrupt context handler attempt to fill the pool
This can lead to a deadlock when the interrupt occurred when the interrupt
hits a region which holds a lock that is required to be taken in the
allocation path.
Add a new can_fill_pool() helper and reorder the exception rule and forbid
this scenario by excluding allocations from hard interrupt context. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7921: fix potential deadlock in mt7921_roc_abort_sync
roc_abort_sync() can deadlock with roc_work(). roc_work() holds
dev->mt76.mutex, while cancel_work_sync() waits for roc_work()
to finish. If the caller already owns the same mutex, both
sides block and no progress is possible.
This deadlock can occur during station removal when
mt76_sta_state() -> mt76_sta_remove() -> mt7921_mac_sta_remove() ->
mt7921_roc_abort_sync() invokes cancel_work_sync() while
roc_work() is still running and holding dev->mt76.mutex.
This avoids the mutex deadlock and preserves exactly-once
work ownership. |
| In the Linux kernel, the following vulnerability has been resolved:
regulator: core: fix locking in regulator_resolve_supply() error path
If late enabling of a supply regulator fails in
regulator_resolve_supply(), the code currently triggers a lockdep
warning:
WARNING: drivers/regulator/core.c:2649 at _regulator_put+0x80/0xa0, CPU#6: kworker/u32:4/596
...
Call trace:
_regulator_put+0x80/0xa0 (P)
regulator_resolve_supply+0x7cc/0xbe0
regulator_register_resolve_supply+0x28/0xb8
as the regulator_list_mutex must be held when calling _regulator_put().
To solve this, simply switch to using regulator_put().
While at it, we should also make sure that no concurrent access happens
to our rdev while we clear out the supply pointer. Add appropriate
locking to ensure that.
While the code in question will be removed altogether in a follow-up
commit, I believe it is still beneficial to have this corrected before
removal for future reference. |
| A flaw was found in the X server's request handling. Non-zero 'bytes to ignore' in a client's request can cause the server to skip processing another client's request, potentially leading to a denial of service. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: sg: Resolve soft lockup issue when opening /dev/sgX
The parameter def_reserved_size defines the default buffer size reserved
for each Sg_fd and should be restricted to a range between 0 and 1,048,576
(see https://tldp.org/HOWTO/SCSI-Generic-HOWTO/proc.html). Although the
function sg_proc_write_dressz enforces this limit, it is possible to bypass
it by directly modifying the module parameter as shown below, which then
causes a soft lockup:
echo -1 > /sys/module/sg/parameters/def_reserved_size
exec 4<> /dev/sg0
watchdog: BUG: soft lockup - CPU#5 stuck for 26 seconds! [bash:537]
Modules loaded:
CPU: 5 UID: 0 PID: 537 Command: bash, kernel version 6.19.0-rc3+ #134,
PREEMPT disabled
Hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS version
1.16.1-2.fc37 dated 04/01/2014
...
Call Trace:
sg_build_reserve+0x5c/0xa0
sg_add_sfp+0x168/0x270
sg_open+0x16e/0x340
chrdev_open+0xbe/0x230
do_dentry_open+0x175/0x480
vfs_open+0x34/0xf0
do_open+0x265/0x3d0
path_openat+0x110/0x290
do_filp_open+0xc3/0x170
do_sys_openat2+0x71/0xe0
__x64_sys_openat+0x6d/0xa0
do_syscall_64+0x62/0x310
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The fix is to use module_param_cb to validate and reject invalid values
assigned to def_reserved_size. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: remove redundant netdev_lock_ops() from conduit ethtool ops
DSA replaces the conduit (master) device's ethtool_ops with its own
wrappers that aggregate stats from both the conduit and DSA switch
ports. Taking the lock again inside the DSA wrappers causes a deadlock.
Stumbled upon this when booting qemu with fbnic and CONFIG_NET_DSA_LOOP=y
(which looks like some kind of testing device that auto-populates the ports
of eth0). `ethtool -i` is enough to deadlock. This means we have basically zero
coverage for DSA stuff with real ops locked devs.
Remove the redundant netdev_lock_ops()/netdev_unlock_ops() calls from
the DSA conduit ethtool wrappers. |
