linux-stable.git/drivers/net, branch v6.12.86

net: bonding: fix use-after-free in bond_xmit_broadcast()

2026-05-07T04:09:47+00:00

commit 2884bf72fb8f03409e423397319205de48adca16 upstream.

bond_xmit_broadcast() reuses the original skb for the last slave
(determined by bond_is_last_slave()) and clones it for others.
Concurrent slave enslave/release can mutate the slave list during
RCU-protected iteration, changing which slave is "last" mid-loop.
This causes the original skb to be double-consumed (double-freed).

Replace the racy bond_is_last_slave() check with a simple index
comparison (i + 1 == slaves_count) against the pre-snapshot slave
count taken via READ_ONCE() before the loop.  This preserves the
zero-copy optimization for the last slave while making the "last"
determination stable against concurrent list mutations.

The UAF can trigger the following crash:

==================================================================
BUG: KASAN: slab-use-after-free in skb_clone
Read of size 8 at addr ffff888100ef8d40 by task exploit/147

CPU: 1 UID: 0 PID: 147 Comm: exploit Not tainted 7.0.0-rc3+ #4 PREEMPTLAZY
Call Trace:
 
 dump_stack_lvl (lib/dump_stack.c:123)
 print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
 kasan_report (mm/kasan/report.c:597)
 skb_clone (include/linux/skbuff.h:1724 include/linux/skbuff.h:1792 include/linux/skbuff.h:3396 net/core/skbuff.c:2108)
 bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5334)
 bond_start_xmit (drivers/net/bonding/bond_main.c:5567 drivers/net/bonding/bond_main.c:5593)
 dev_hard_start_xmit (include/linux/netdevice.h:5325 include/linux/netdevice.h:5334 net/core/dev.c:3871 net/core/dev.c:3887)
 __dev_queue_xmit (include/linux/netdevice.h:3601 net/core/dev.c:4838)
 ip6_finish_output2 (include/net/neighbour.h:540 include/net/neighbour.h:554 net/ipv6/ip6_output.c:136)
 ip6_finish_output (net/ipv6/ip6_output.c:208 net/ipv6/ip6_output.c:219)
 ip6_output (net/ipv6/ip6_output.c:250)
 ip6_send_skb (net/ipv6/ip6_output.c:1985)
 udp_v6_send_skb (net/ipv6/udp.c:1442)
 udpv6_sendmsg (net/ipv6/udp.c:1733)
 __sys_sendto (net/socket.c:730 net/socket.c:742 net/socket.c:2206)
 __x64_sys_sendto (net/socket.c:2209)
 do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
 

Allocated by task 147:

Freed by task 147:

The buggy address belongs to the object at ffff888100ef8c80
 which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 192 bytes inside of
 freed 224-byte region [ffff888100ef8c80, ffff888100ef8d60)

Memory state around the buggy address:
 ffff888100ef8c00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888100ef8c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888100ef8d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                                    ^
 ffff888100ef8d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff888100ef8e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Fixes: 4e5bd03ae346 ("net: bonding: fix bond_xmit_broadcast return value error bug")
Reported-by: Weiming Shi 
Signed-off-by: Xiang Mei 
Link: https://patch.msgid.link/20260326075553.3960562-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin 
Signed-off-by: Kevin Berry 
Signed-off-by: Greg Kroah-Hartman

RDMA/mana_ib: Disable RX steering on RSS QP destroy

2026-05-07T04:09:45+00:00

[ Upstream commit dbeb256e8dd87233d891b170c0b32a6466467036 ]

When an RSS QP is destroyed (e.g. DPDK exit), mana_ib_destroy_qp_rss()
destroys the RX WQ objects but does not disable vPort RX steering in
firmware. This leaves stale steering configuration that still points to
the destroyed RX objects.

If traffic continues to arrive (e.g. peer VM is still transmitting) and
the VF interface is subsequently brought up (mana_open), the firmware
may deliver completions using stale CQ IDs from the old RX objects.
These CQ IDs can be reused by the ethernet driver for new TX CQs,
causing RX completions to land on TX CQs:

  WARNING: mana_poll_tx_cq+0x1b8/0x220 [mana]  (is_sq == false)
  WARNING: mana_gd_process_eq_events+0x209/0x290 (cq_table lookup fails)

Fix this by disabling vPort RX steering before destroying RX WQ objects.
Note that mana_fence_rqs() cannot be used here because the fence
completion is delivered on the CQ, which is polled by user-mode (e.g.
DPDK) and not visible to the kernel driver.

Refactor the disable logic into a shared mana_disable_vport_rx() in
mana_en, exported for use by mana_ib, replacing the duplicate code.
The ethernet driver's mana_dealloc_queues() is also updated to call
this common function.

Fixes: 0266a177631d ("RDMA/mana_ib: Add a driver for Microsoft Azure Network Adapter")
Cc: stable@vger.kernel.org
Signed-off-by: Long Li 
Link: https://patch.msgid.link/20260325194100.1929056-1-longli@microsoft.com
Signed-off-by: Leon Romanovsky 
[ kept early-return error handling and used unquoted NET_MANA namespace in EXPORT_SYMBOL_NS ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

wifi: mwifiex: fix use-after-free in mwifiex_adapter_cleanup()

2026-05-07T04:09:44+00:00

[ Upstream commit ae5e95d4157481693be2317e3ffcd84e36010cbb ]

The mwifiex_adapter_cleanup() function uses timer_delete()
(non-synchronous) for the wakeup_timer before the adapter structure is
freed. This is incorrect because timer_delete() does not wait for any
running timer callback to complete.

If the wakeup_timer callback (wakeup_timer_fn) is executing when
mwifiex_adapter_cleanup() is called, the callback will continue to
access adapter fields (adapter->hw_status, adapter->if_ops.card_reset,
etc.) which may be freed by mwifiex_free_adapter() called later in the
mwifiex_remove_card() path.

Use timer_delete_sync() instead to ensure any running timer callback has
completed before returning.

Fixes: 4636187da60b ("mwifiex: add wakeup timer based recovery mechanism")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Hodges 
Link: https://patch.msgid.link/20260206194401.2346-1-git@danielhodges.dev
Signed-off-by: Johannes Berg 
[ changed `timer_delete_sync()` to `del_timer_sync()` ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

wifi: mt76: mt792x: fix mt7925u USB WFSYS reset handling

2026-05-07T04:09:44+00:00

[ Upstream commit 56154fef47d104effa9f29ed3db4f805cbc0d640 ]

mt7925u uses different reset/status registers from mt7921u. Reusing the
mt7921u register set causes the WFSYS reset to fail.

Add a chip-specific descriptor in mt792xu_wfsys_reset() to select the
correct registers and fix mt7925u failing to initialize after a warm
reboot.

Fixes: d28e1a48952e ("wifi: mt76: mt792x: introduce mt792x-usb module")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Wang 
Link: https://patch.msgid.link/20260311002825.15502-2-sean.wang@kernel.org
Signed-off-by: Felix Fietkau 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

wifi: mt76: mt792x: describe USB WFSYS reset with a descriptor

2026-05-07T04:09:44+00:00

[ Upstream commit e6f48512c1ceebcd1ce6bb83df3b3d56a261507d ]

Prepare mt792xu_wfsys_reset() for chips that share the same USB WFSYS
reset flow but use different register definitions.

This is a pure refactor of the current mt7921u path and keeps the reset
sequence unchanged.

Signed-off-by: Sean Wang 
Link: https://patch.msgid.link/20260311002825.15502-1-sean.wang@kernel.org
Signed-off-by: Felix Fietkau 
Stable-dep-of: 56154fef47d1 ("wifi: mt76: mt792x: fix mt7925u USB WFSYS reset handling")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

can: ucan: fix devres lifetime

2026-05-07T04:09:41+00:00

commit fed4626501c871890da287bec62a96e52da1af89 upstream.

USB drivers bind to USB interfaces and any device managed resources
should have their lifetime tied to the interface rather than parent USB
device. This avoids issues like memory leaks when drivers are unbound
without their devices being physically disconnected (e.g. on probe
deferral or configuration changes).

Fix the control message buffer lifetime so that it is released on driver
unbind.

Fixes: 9f2d3eae88d2 ("can: ucan: add driver for Theobroma Systems UCAN devices")
Cc: stable@vger.kernel.org	# 4.19
Cc: Jakob Unterwurzacher 
Signed-off-by: Johan Hovold 
Link: https://patch.msgid.link/20260327104520.1310158-1-johan@kernel.org
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

wifi: rtl8xxxu: fix potential use of uninitialized value

2026-05-07T04:09:40+00:00

commit f8a2fc809bfeb49130709b31a4d357a049f28547 upstream.

The local variables 'mcs' and 'nss' in rtl8xxxu_update_ra_report() are
passed to rtl8xxxu_desc_to_mcsrate() as output parameters. If the helper
function encounters an unhandled rate index, it may return without setting
these values, leading to the use of uninitialized stack data.

Remove the helper rtl8xxxu_desc_to_mcsrate() and inline the logic into
rtl8xxxu_update_ra_report(). This fixes the use of uninitialized 'mcs'
and 'nss' variables for legacy rates.

The new implementation explicitly handles:
- Legacy rates: Set bitrate only.
- HT rates (MCS0-15): Set MCS flags, index, and NSS (1 or 2) directly.
- Invalid rates: Return early.

Fixes: 7de16123d9e2 ("wifi: rtl8xxxu: Introduce rtl8xxxu_update_ra_report")
Cc: stable@vger.kernel.org
Suggested-by: Ping-Ke Shih 
Signed-off-by: Yi Cong 
Link: https://lore.kernel.org/all/96e31963da0c42dcb52ce44f818963d7@realtek.com/
Signed-off-by: Ping-Ke Shih 
Link: https://patch.msgid.link/20260306071627.56501-1-cong.yi@linux.dev
Signed-off-by: Greg Kroah-Hartman

net: ks8851: Avoid excess softirq scheduling

2026-05-07T04:09:33+00:00

commit 22230e68b2cf1ab6b027be8cf1198164a949c4fa upstream.

The code injects a packet into netif_rx() repeatedly, which will add
it to its internal NAPI and schedule a softirq, and process it. It is
more efficient to queue multiple packets and process them all at the
local_bh_enable() time.

Reviewed-by: Sebastian Andrzej Siewior 
Fixes: e0863634bf9f ("net: ks8851: Queue RX packets in IRQ handler instead of disabling BHs")
Cc: stable@vger.kernel.org
Signed-off-by: Marek Vasut 
Link: https://patch.msgid.link/20260415231020.455298-2-marex@nabladev.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

netconsole: avoid out-of-bounds access on empty string in trim_newline()

2026-05-07T04:09:33+00:00

commit 7079c8c13f2d33992bc846240517d88f4ab07781 upstream.

trim_newline() unconditionally dereferences s[len - 1] after computing
len = strnlen(s, maxlen). When the string is empty, len is 0 and the
expression underflows to s[(size_t)-1], reading (and potentially
writing) one byte before the buffer.

The two callers feed trim_newline() with the result of strscpy() from
configfs store callbacks (dev_name_store, userdatum_value_store).
configfs guarantees count >= 1 reaches the callback, but the byte
itself can be NUL: a userspace write(fd, "\0", 1) leaves the
destination empty after strscpy() and triggers the underflow. The OOB
write only fires if the adjacent byte happens to be '\n', so this is
not a security issue, but the access is undefined behaviour either way.

This pattern is commonly flagged by LLM-based code reviewers. While it
is not a security fix, the underlying access is undefined behaviour and
the change is small and self-contained, so it is a reasonable candidate
for the stable trees.

Guard the dereference on a non-zero length.

Fixes: ae001dc67907 ("net: netconsole: move newline trimming to function")
Cc: stable@vger.kernel.org
Signed-off-by: Breno Leitao 
Reviewed-by: Gustavo Luiz Duarte 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20260420-netcons_trim_newline-v1-1-dc35889aeedf@debian.org
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

net: ks8851: Reinstate disabling of BHs around IRQ handler

2026-05-07T04:09:33+00:00

commit 5c9fcac3c872224316714d0d8914d9af16c76a6d upstream.

If the driver executes ks8851_irq() AND a TX packet has been sent, then
the driver enables TX queue via netif_wake_queue() which schedules TX
softirq to queue packets for this device.

If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by
the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to
allocate SKBs for the received packets. If netdev_alloc_skb_ip_align()
is called with BH enabled, then local_bh_enable() at the end of
netdev_alloc_skb_ip_align() will trigger the pending softirq processing,
which may ultimately call the .xmit callback ks8851_start_xmit_par().
The ks8851_start_xmit_par() will try to lock struct ks8851_net_par
.lock spinlock, which is already locked by ks8851_irq() from which
ks8851_start_xmit_par() was called. This leads to a deadlock, which
is reported by the kernel, including a trace listed below.

If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0
("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock
can also be triggered without received packet in the RX FIFO. The
pending softirqs will be processed on return from
spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the
deadlock as well.

Fix the problem by disabling BH around critical sections, including the
IRQ handler, thus preventing the net_tx_action() softirq from triggering
during these critical sections. The net_tx_action() softirq is triggered
once BH are re-enabled and at the end of the IRQ handler, once all the
other IRQ handler actions have been completed.

 __schedule from schedule_rtlock+0x1c/0x34
 schedule_rtlock from rtlock_slowlock_locked+0x548/0x904
 rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c
 rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8
 ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44
 netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188
 dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c
 sch_direct_xmit from __qdisc_run+0x1f8/0x4ec
 __qdisc_run from qdisc_run+0x1c/0x28
 qdisc_run from net_tx_action+0x1f0/0x268
 net_tx_action from handle_softirqs+0x1a4/0x270
 handle_softirqs from __local_bh_enable_ip+0xcc/0xe0
 __local_bh_enable_ip from __alloc_skb+0xd8/0x128
 __alloc_skb from __netdev_alloc_skb+0x3c/0x19c
 __netdev_alloc_skb from ks8851_irq+0x388/0x4d4
 ks8851_irq from irq_thread_fn+0x24/0x64
 irq_thread_fn from irq_thread+0x178/0x28c
 irq_thread from kthread+0x12c/0x138
 kthread from ret_from_fork+0x14/0x28

Reviewed-by: Sebastian Andrzej Siewior 
Fixes: e0863634bf9f ("net: ks8851: Queue RX packets in IRQ handler instead of disabling BHs")
Cc: stable@vger.kernel.org
Signed-off-by: Marek Vasut 
Link: https://patch.msgid.link/20260415231020.455298-1-marex@nabladev.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman