kernel/linux.git/drivers/net/hamradio, branch v5.10.257

hamradio: baycom_epp: Fix return type of baycom_send_packet()

2023-01-14T09:16:16+00:00

[ Upstream commit c5733e5b15d91ab679646ec3149e192996a27d5d ] With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/net/hamradio/baycom_epp.c:1119:25: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = baycom_send_packet, ^~~~~~~~~~~~~~~~~~ 1 error generated. ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of baycom_send_packet() to match the prototype's to resolve the warning and CFI failure. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20221102160610.1186145-1-nathan@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hamradio: don't call dev_kfree_skb() under spin_lock_irqsave()

2023-01-14T09:15:43+00:00

[ Upstream commit 3727f742915f04f6fc550b80cf406999bd4e90d0 ] It is not allowed to call kfree_skb() or consume_skb() from hardware interrupt context or with hardware interrupts being disabled. It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead. The difference between them is free reason, dev_kfree_skb_irq() means the SKB is dropped in error and dev_consume_skb_irq() means the SKB is consumed in normal. In scc_discard_buffers(), dev_kfree_skb() is called to discard the SKBs, so replace it with dev_kfree_skb_irq(). In scc_net_tx(), dev_kfree_skb() is called to drop the SKB that exceed queue length, so replace it with dev_kfree_skb_irq(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Yang Yingliang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

hamradio: fix issue of dev reference count leakage in bpq_device_event()

2022-11-16T08:57:11+00:00

[ Upstream commit 85cbaf032d3cd9f595152625eda5d4ecb1d6d78d ] When following tests are performed, it will cause dev reference counting leakage. a)ip link add bond2 type bond mode balance-rr b)ip link set bond2 up c)ifenslave -f bond2 rose1 d)ip link del bond2 When new bond device is created, the default type of the bond device is ether. And the bond device is up, bpq_device_event() receives the message and creates a new bpq device. In this case, the reference count value of dev is hold once. But after "ifenslave -f bond2 rose1" command is executed, the type of the bond device is changed to rose. When the bond device is unregistered, bpq_device_event() will not put the dev reference count. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Zhengchao Shao Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

hamradio: remove needs_free_netdev to avoid UAF

2022-04-20T07:23:09+00:00

commit 81b1d548d00bcd028303c4f3150fa753b9b8aa71 upstream. The former patch "defer 6pack kfree after unregister_netdev" reorders the kfree of two buffer after the unregister_netdev to prevent the race condition. It also adds free_netdev() function in sixpack_close(), which is a direct copy from the similar code in mkiss_close(). However, in sixpack driver, the flag needs_free_netdev is set to true in sp_setup(), hence the unregister_netdev() will free the netdev automatically. Therefore, as the sp is netdev_priv, use-after-free occurs. This patch removes the needs_free_netdev = true and just let the free_netdev to finish this deallocation task. Fixes: 0b9111922b1f ("hamradio: defer 6pack kfree after unregister_netdev") Signed-off-by: Lin Ma Link: https://lore.kernel.org/r/20211111141402.7551-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Xu Jia Signed-off-by: Greg Kroah-Hartman

hamradio: defer 6pack kfree after unregister_netdev

2022-04-20T07:23:09+00:00

commit 0b9111922b1f399aba6ed1e1b8f2079c3da1aed8 upstream. There is a possible race condition (use-after-free) like below (USE) | (FREE) dev_queue_xmit | __dev_queue_xmit | __dev_xmit_skb | sch_direct_xmit | ... xmit_one | netdev_start_xmit | tty_ldisc_kill __netdev_start_xmit | 6pack_close sp_xmit | kfree sp_encaps | | According to the patch "defer ax25 kfree after unregister_netdev", this patch reorder the kfree after the unregister_netdev to avoid the possible UAF as the unregister_netdev() is well synchronized and won't return if there is a running routine. Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Xu Jia Signed-off-by: Greg Kroah-Hartman

drivers: hamradio: 6pack: fix UAF bug caused by mod_timer()

2022-04-08T12:39:55+00:00

commit efe4186e6a1b54bf38b9e05450d43b0da1fd7739 upstream. When a 6pack device is detaching, the sixpack_close() will act to cleanup necessary resources. Although del_timer_sync() in sixpack_close() won't return if there is an active timer, one could use mod_timer() in sp_xmit_on_air() to wake up timer again by calling userspace syscall such as ax25_sendmsg(), ax25_connect() and ax25_ioctl(). This unexpected waked handler, sp_xmit_on_air(), realizes nothing about the undergoing cleanup and may still call pty_write() to use driver layer resources that have already been released. One of the possible race conditions is shown below: (USE) | (FREE) ax25_sendmsg() | ax25_queue_xmit() | ... | sp_xmit() | sp_encaps() | sixpack_close() sp_xmit_on_air() | del_timer_sync(&sp->tx_t) mod_timer(&sp->tx_t,...) | ... | unregister_netdev() | ... (wait a while) | tty_release() | tty_release_struct() | release_tty() sp_xmit_on_air() | tty_kref_put(tty_struct) //FREE pty_write(tty_struct) //USE | ... The corresponding fail log is shown below: =============================================================== BUG: KASAN: use-after-free in __run_timers.part.0+0x170/0x470 Write of size 8 at addr ffff88800a652ab8 by task swapper/2/0 ... Call Trace: ... queue_work_on+0x3f/0x50 pty_write+0xcd/0xe0pty_write+0xcd/0xe0 sp_xmit_on_air+0xb2/0x1f0 call_timer_fn+0x28/0x150 __run_timers.part.0+0x3c2/0x470 run_timer_softirq+0x3b/0x80 __do_softirq+0xf1/0x380 ... This patch reorders the del_timer_sync() after the unregister_netdev() to avoid UAF bugs. Because the unregister_netdev() is well synchronized, it flushs out any pending queues, waits the refcount of net_device decreases to zero and removes net_device from kernel. There is not any running routines after executing unregister_netdev(). Therefore, we could not arouse timer from userspace again. Signed-off-by: Duoming Zhou Reviewed-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hamradio: fix macro redefine warning

2022-03-08T18:09:39+00:00

commit 16517829f2e02f096fb5ea9083d160381127faf3 upstream. MIPS/IA64 define END as assembly function ending, which conflict with END definition in mkiss.c, just undef it at first Reported-by: lkp@intel.com Signed-off-by: Huang Pei Signed-off-by: David S. Miller Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

yam: fix a memory leak in yam_siocdevprivate()

2022-02-01T16:25:47+00:00

[ Upstream commit 29eb31542787e1019208a2e1047bb7c76c069536 ] ym needs to be free when ym->cmd != SIOCYAMSMCS. Fixes: 0781168e23a2 ("yam: fix a missing-check bug") Signed-off-by: Hangyu Hua Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

hamradio: improve the incomplete fix to avoid NPD

2021-12-29T11:26:08+00:00

commit b2f37aead1b82a770c48b5d583f35ec22aabb61e upstream. The previous commit 3e0588c291d6 ("hamradio: defer ax25 kfree after unregister_netdev") reorder the kfree operations and unregister_netdev operation to prevent UAF. This commit improves the previous one by also deferring the nullify of the ax->tty pointer. Otherwise, a NULL pointer dereference bug occurs. Partial of the stack trace is shown below. BUG: kernel NULL pointer dereference, address: 0000000000000538 RIP: 0010:ax_xmit+0x1f9/0x400 ... Call Trace: dev_hard_start_xmit+0xec/0x320 sch_direct_xmit+0xea/0x240 __qdisc_run+0x166/0x5c0 __dev_queue_xmit+0x2c7/0xaf0 ax25_std_establish_data_link+0x59/0x60 ax25_connect+0x3a0/0x500 ? security_socket_connect+0x2b/0x40 __sys_connect+0x96/0xc0 ? __hrtimer_init+0xc0/0xc0 ? common_nsleep+0x2e/0x50 ? switch_fpu_return+0x139/0x1a0 __x64_sys_connect+0x11/0x20 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The crash point is shown as below static void ax_encaps(...) { ... set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); // ax->tty = NULL! ... } By placing the nullify action after the unregister_netdev, the ax->tty pointer won't be assigned as NULL net_device framework layer is well synchronized. Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hamradio: defer ax25 kfree after unregister_netdev

2021-12-29T11:26:08+00:00

commit 3e0588c291d6ce225f2b891753ca41d45ba42469 upstream. There is a possible race condition (use-after-free) like below (USE) | (FREE) ax25_sendmsg | ax25_queue_xmit | dev_queue_xmit | __dev_queue_xmit | __dev_xmit_skb | sch_direct_xmit | ... xmit_one | netdev_start_xmit | tty_ldisc_kill __netdev_start_xmit | mkiss_close ax_xmit | kfree ax_encaps | | Even though there are two synchronization primitives before the kfree: 1. wait_for_completion(&ax->dead). This can prevent the race with routines from mkiss_ioctl. However, it cannot stop the routine coming from upper layer, i.e., the ax25_sendmsg. 2. netif_stop_queue(ax->dev). It seems that this line of code aims to halt the transmit queue but it fails to stop the routine that already being xmit. This patch reorder the kfree after the unregister_netdev to avoid the possible UAF as the unregister_netdev() is well synchronized and won't return if there is a running routine. Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman