kernel/linux.git/drivers/net/wan, branch v6.18.40

net: ixp4xx_hss: fix duplicate HDLC netdev allocation

2026-07-24T14:17:12+00:00

commit db818b0e8af7bac16860116a19c341a63d6677b4 upstream. ixp4xx_hss_probe() allocates two HDLC netdevs. The first one is stored in ndev, initialized, and registered with register_hdlc_device(). The second one is stored in port->netdev and later used by the remove path for unregister_hdlc_device() and free_netdev(). This means that the registered netdev is not the same object that is unregistered and freed on remove. It also leaks the first allocation if the second alloc_hdlcdev() call fails, and the first allocation is not checked before ndev is used. Older code allocated the HDLC netdev only once and stored the same object in both the local variable and port->netdev. The buggy conversion split this into two alloc_hdlcdev() calls. A later rename changed the local variable name to ndev, but the underlying mismatch remained. Fix this by allocating the HDLC netdev only once and assigning the same object to port->netdev. Fixes: 99ebe65eb9c0 ("net: ixp4xx_hss: move out assignment in if condition") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Reviewed-by: Linus Walleij Link: https://patch.msgid.link/20260622043015.643637-1-haoxiang_li2024@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

hdlc_ppp: sync per-proto timers before freeing hdlc state

2026-07-04T11:44:19+00:00

commit c78a4e41ab5ead6193ad8a2dd92e8906bae659fa upstream. Each PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp registers a timer via timer_setup(). That struct ppp is the hdlc->state allocation, which detach_hdlc_protocol() frees with kfree() in both teardown paths: unregister_hdlc_device() and the re-attach inside attach_hdlc_protocol(). The ppp proto never registered a .detach callback, so detach_hdlc_protocol() performs no timer synchronization before the kfree(). The only cancel, timer_delete(&proto->timer) in ppp_cp_event(), is partial (it does not wait for a running callback) and only runs on the ->CLOSED transition; ppp_stop()/ppp_close() do not sync either. A ppp_timer callback already executing (blocked on ppp->lock) survives the kfree and then dereferences proto->state / ppp->lock in freed memory, leading to a use-after-free. Fix this by adding a .detach helper that calls timer_shutdown_sync() on every per-proto timer. detach_hdlc_protocol() invokes proto->detach(dev) before kfree(hdlc->state), so timer_shutdown_sync() now runs on both free paths. timer_shutdown_sync() is used instead of timer_delete_sync() because the keepalive path re-arms the timer through add_timer()/mod_timer() and shutdown blocks any re-activation during teardown. Initialize the per-protocol timers in ppp_ioctl() when the protocol is attached, and remove the now-redundant timer_setup() from ppp_start(), so that the timers are initialized exactly once at attach time and ppp_timer_release() never operates on uninitialized timer_list structures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so struct ppp's protos[i].timer is uninitialized garbage until the first timer_setup(); without this init-at-attach, attaching the PPP protocol without ever bringing the device up would leave timer_shutdown_sync() operating on uninitialized memory in .detach. Moving the init out of ppp_start() (which only runs on NETDEV_UP) into the attach path makes the initialization unconditional and avoids initializing the same timer_list twice. This bug was found by static analysis. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Fan Wu Link: https://patch.msgid.link/20260617020518.116319-1-fanwu01@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: lapbether: handle NETDEV_PRE_TYPE_CHANGE

2026-04-22T11:22:19+00:00

[ Upstream commit b120e4432f9f56c7103133d6a11245e617695adb ] lapbeth_data_transmit() expects the underlying device type to be ARPHRD_ETHER. Returning NOTIFY_BAD from lapbeth_device_event() makes sure bonding driver can not break this expectation. Fixes: 872254dd6b1f ("net/bonding: Enable bonding to enslave non ARPHRD_ETHER") Reported-by: syzbot+d8c285748fa7292580a9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/69cd22a1.050a0220.70c3a.0002.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Martin Schiller Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260402103519.1201565-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: wan/fsl_ucc_hdlc: Fix dma_free_coherent() in uhdlc_memclean()

2026-03-04T12:21:27+00:00

[ Upstream commit 36bd7d5deef936c4e1e3cd341598140e5c14c1d3 ] The priv->rx_buffer and priv->tx_buffer are alloc'd together as contiguous buffers in uhdlc_init() but freed as two buffers in uhdlc_memclean(). Change the cleanup to only call dma_free_coherent() once on the whole buffer. Reviewed-by: Christophe Leroy (CS GROUP) Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC") Cc: Signed-off-by: Thomas Fourier Link: https://patch.msgid.link/20260206085334.21195-2-fourier.thomas@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets

2026-03-04T12:20:49+00:00

[ Upstream commit bae8a5d2e759da2e0cba33ab2080deee96a09373 ] When the FarSync T-series card is being detached, the fst_card_info is deallocated in fst_remove_one(). However, the fst_tx_task or fst_int_task may still be running or pending, leading to use-after-free bugs when the already freed fst_card_info is accessed in fst_process_tx_work_q() or fst_process_int_work_q(). A typical race condition is depicted below: CPU 0 (cleanup) | CPU 1 (tasklet) | fst_start_xmit() fst_remove_one() | tasklet_schedule() unregister_hdlc_device()| | fst_process_tx_work_q() //handler kfree(card) //free | do_bottom_half_tx() | card-> //use The following KASAN trace was captured: ================================================================== BUG: KASAN: slab-use-after-free in do_bottom_half_tx+0xb88/0xd00 Read of size 4 at addr ffff88800aad101c by task ksoftirqd/3/32 ... Call Trace: dump_stack_lvl+0x55/0x70 print_report+0xcb/0x5d0 ? do_bottom_half_tx+0xb88/0xd00 kasan_report+0xb8/0xf0 ? do_bottom_half_tx+0xb88/0xd00 do_bottom_half_tx+0xb88/0xd00 ? _raw_spin_lock_irqsave+0x85/0xe0 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? __pfx___hrtimer_run_queues+0x10/0x10 fst_process_tx_work_q+0x67/0x90 tasklet_action_common+0x1fa/0x720 ? hrtimer_interrupt+0x31f/0x780 handle_softirqs+0x176/0x530 __irq_exit_rcu+0xab/0xe0 sysvec_apic_timer_interrupt+0x70/0x80 ... Allocated by task 41 on cpu 3 at 72.330843s: kasan_save_stack+0x24/0x50 kasan_save_track+0x17/0x60 __kasan_kmalloc+0x7f/0x90 fst_add_one+0x1a5/0x1cd0 local_pci_probe+0xdd/0x190 pci_device_probe+0x341/0x480 really_probe+0x1c6/0x6a0 __driver_probe_device+0x248/0x310 driver_probe_device+0x48/0x210 __device_attach_driver+0x160/0x320 bus_for_each_drv+0x101/0x190 __device_attach+0x198/0x3a0 device_initial_probe+0x78/0xa0 pci_bus_add_device+0x81/0xc0 pci_bus_add_devices+0x7e/0x190 enable_slot+0x9b9/0x1130 acpiphp_check_bridge.part.0+0x2e1/0x460 acpiphp_hotplug_notify+0x36c/0x3c0 acpi_device_hotplug+0x203/0xb10 acpi_hotplug_work_fn+0x59/0x80 ... Freed by task 41 on cpu 1 at 75.138639s: kasan_save_stack+0x24/0x50 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x43/0x70 kfree+0x135/0x410 fst_remove_one+0x2ca/0x540 pci_device_remove+0xa6/0x1d0 device_release_driver_internal+0x364/0x530 pci_stop_bus_device+0x105/0x150 pci_stop_and_remove_bus_device+0xd/0x20 disable_slot+0x116/0x260 acpiphp_disable_and_eject_slot+0x4b/0x190 acpiphp_hotplug_notify+0x230/0x3c0 acpi_device_hotplug+0x203/0xb10 acpi_hotplug_work_fn+0x59/0x80 ... The buggy address belongs to the object at ffff88800aad1000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 28 bytes inside of freed 1024-byte region The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xaad0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff888007042dc0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 0100000000000040 ffff888007042dc0 dead000000000122 0000000000000000 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 0100000000000003 ffffea00002ab401 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88800aad0f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800aad0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88800aad1000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88800aad1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88800aad1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fix this by ensuring that both fst_tx_task and fst_int_task are properly canceled before the fst_card_info is released. Add tasklet_kill() in fst_remove_one() to synchronize with any pending or running tasklets. Since unregister_hdlc_device() stops data transmission and reception, and fst_disable_intr() prevents further interrupts, it is appropriate to place tasklet_kill() after these calls. The bugs were identified through static analysis. To reproduce the issue and validate the fix, a FarSync T-series card was simulated in QEMU and delays(e.g., mdelay()) were introduced within the tasklet handler to increase the likelihood of triggering the race condition. Fixes: 2f623aaf9f31 ("net: farsync: Fix kmemleak when rmmods farsync") Signed-off-by: Duoming Zhou Reviewed-by: Jijie Shao Link: https://patch.msgid.link/20260219124637.72578-1-duoming@zju.edu.cn Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: wan: framer: pef2256: Switch to devm_mfd_add_devices()

2025-11-06T02:02:34+00:00

The driver calls mfd_add_devices() but fails to call mfd_remove_devices() in error paths after successful MFD device registration and in the remove function. This leads to resource leaks where MFD child devices are not properly unregistered. Replace mfd_add_devices with devm_mfd_add_devices to automatically manage the device resources. Fixes: c96e976d9a05 ("net: wan: framer: Add support for the Lantiq PEF2256 framer") Suggested-by: Herve Codina Signed-off-by: Haotian Zhang Acked-by: Herve Codina Link: https://patch.msgid.link/20251105034716.662-1-vulab@iscas.ac.cn Signed-off-by: Jakub Kicinski

net: wan: framer: Add version sysfs attribute for the Lantiq PEF2256 framer

2025-09-26T22:13:01+00:00

Lantiq PEF2256 framer has some little differences in behaviour depending on its version. Add a sysfs attribute to allow user applications to know the version. Signed-off-by: Christophe Leroy Link: https://patch.msgid.link/77a27941d6924b1009df0162ed9f0fa07ed6e431.1758726302.git.christophe.leroy@csgroup.eu Signed-off-by: Jakub Kicinski

wan: framer: pef2256: use %pe in print format

2025-09-19T14:27:24+00:00

New cocci check complains: drivers/net/wan/framer/pef2256/pef2256.c:733:3-10: WARNING: Consider using %pe to print PTR_ERR() Link: https://lore.kernel.org/1758192227-701925-1-git-send-email-tariqt@nvidia.com Acked-by: Herve Codina Link: https://patch.msgid.link/20250918134637.2226614-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: lapbether: ignore ops-locked netdevs

2025-08-08T20:22:28+00:00

Syzkaller managed to trigger lock dependency in xsk_notify via register_netdevice. As discussed in [0], using register_netdevice in the notifiers is problematic so skip adding lapbeth for ops-locked devices. xsk_notifier+0xa4/0x280 net/xdp/xsk.c:1645 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0xf9d/0x2700 net/core/dev.c:12077 unregister_netdevice_many net/core/dev.c:12140 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11984 register_netdevice+0x18f1/0x2270 net/core/dev.c:11149 lapbeth_new_device drivers/net/wan/lapbether.c:420 [inline] lapbeth_device_event+0x5b1/0xbe0 drivers/net/wan/lapbether.c:462 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497 netif_change_flags+0x108/0x160 net/core/dev.c:9526 dev_change_flags+0xba/0x250 net/core/dev_api.c:68 devinet_ioctl+0x11d5/0x1f50 net/ipv4/devinet.c:1200 inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1001 0: https://lore.kernel.org/netdev/20250625140357.6203d0af@kernel.org/ Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP") Suggested-by: Jakub Kicinski Reported-by: syzbot+e67ea9c235b13b4f0020@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e67ea9c235b13b4f0020 Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250806213726.1383379-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com