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2022-08-22ax25: move from strlcpy with unused retval to strscpyWolfram Sang1-1/+1
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818210206.8299-1-wsa+renesas@sang-engineering.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni1-2/+2
Conflicts: net/ax25/af_ax25.c d7c4c9e075f8c ("ax25: fix incorrect dev_tracker usage") d62607c3fe459 ("net: rename reference+tracking helpers") drivers/net/netdevsim/fib.c 180a6a3ee60a ("netdevsim: fib: Fix reference count leak on route deletion failure") 012ec02ae441 ("netdevsim: convert driver to use unlocked devlink API during init/fini") Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-07-28ax25: fix incorrect dev_tracker usageEric Dumazet1-2/+2
While investigating a separate rose issue [1], and enabling CONFIG_NET_DEV_REFCNT_TRACKER=y, Bernard reported an orthogonal ax25 issue [2] An ax25_dev can be used by one (or many) struct ax25_cb. We thus need different dev_tracker, one per struct ax25_cb. After this patch is applied, we are able to focus on rose. [1] https://lore.kernel.org/netdev/fb7544a1-f42e-9254-18cc-c9b071f4ca70@free.fr/ [2] [ 205.798723] reference already released. [ 205.798732] allocated in: [ 205.798734] ax25_bind+0x1a2/0x230 [ax25] [ 205.798747] __sys_bind+0xea/0x110 [ 205.798753] __x64_sys_bind+0x18/0x20 [ 205.798758] do_syscall_64+0x5c/0x80 [ 205.798763] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798768] freed in: [ 205.798770] ax25_release+0x115/0x370 [ax25] [ 205.798778] __sock_release+0x42/0xb0 [ 205.798782] sock_close+0x15/0x20 [ 205.798785] __fput+0x9f/0x260 [ 205.798789] ____fput+0xe/0x10 [ 205.798792] task_work_run+0x64/0xa0 [ 205.798798] exit_to_user_mode_prepare+0x18b/0x190 [ 205.798804] syscall_exit_to_user_mode+0x26/0x40 [ 205.798808] do_syscall_64+0x69/0x80 [ 205.798812] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798827] ------------[ cut here ]------------ [ 205.798829] WARNING: CPU: 2 PID: 2605 at lib/ref_tracker.c:136 ref_tracker_free.cold+0x60/0x81 [ 205.798837] Modules linked in: rose netrom mkiss ax25 rfcomm cmac algif_hash algif_skcipher af_alg bnep snd_hda_codec_hdmi nls_iso8859_1 i915 rtw88_8821ce rtw88_8821c x86_pkg_temp_thermal rtw88_pci intel_powerclamp rtw88_core snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio coretemp snd_hda_intel kvm_intel snd_intel_dspcfg mac80211 snd_hda_codec kvm i2c_algo_bit drm_buddy drm_dp_helper btusb drm_kms_helper snd_hwdep btrtl snd_hda_core btbcm joydev crct10dif_pclmul btintel crc32_pclmul ghash_clmulni_intel mei_hdcp btmtk intel_rapl_msr aesni_intel bluetooth input_leds snd_pcm crypto_simd syscopyarea processor_thermal_device_pci_legacy sysfillrect cryptd intel_soc_dts_iosf snd_seq sysimgblt ecdh_generic fb_sys_fops rapl libarc4 processor_thermal_device intel_cstate processor_thermal_rfim cec snd_timer ecc snd_seq_device cfg80211 processor_thermal_mbox mei_me processor_thermal_rapl mei rc_core at24 snd intel_pch_thermal intel_rapl_common ttm soundcore int340x_thermal_zone video [ 205.798948] mac_hid acpi_pad sch_fq_codel ipmi_devintf ipmi_msghandler drm msr parport_pc ppdev lp parport ramoops pstore_blk reed_solomon pstore_zone efi_pstore ip_tables x_tables autofs4 hid_generic usbhid hid i2c_i801 i2c_smbus r8169 xhci_pci ahci libahci realtek lpc_ich xhci_pci_renesas [last unloaded: ax25] [ 205.798992] CPU: 2 PID: 2605 Comm: ax25ipd Not tainted 5.18.11-F6BVP #3 [ 205.798996] Hardware name: To be filled by O.E.M. To be filled by O.E.M./CK3, BIOS 5.011 09/16/2020 [ 205.798999] RIP: 0010:ref_tracker_free.cold+0x60/0x81 [ 205.799005] Code: e8 d2 01 9b ff 83 7b 18 00 74 14 48 c7 c7 2f d7 ff 98 e8 10 6e fc ff 8b 7b 18 e8 b8 01 9b ff 4c 89 ee 4c 89 e7 e8 5d fd 07 00 <0f> 0b b8 ea ff ff ff e9 30 05 9b ff 41 0f b6 f7 48 c7 c7 a0 fa 4e [ 205.799008] RSP: 0018:ffffaf5281073958 EFLAGS: 00010286 [ 205.799011] RAX: 0000000080000000 RBX: ffff9a0bd687ebe0 RCX: 0000000000000000 [ 205.799014] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 00000000ffffffff [ 205.799016] RBP: ffffaf5281073a10 R08: 0000000000000003 R09: fffffffffffd5618 [ 205.799019] R10: 0000000000ffff10 R11: 000000000000000f R12: ffff9a0bc53384d0 [ 205.799022] R13: 0000000000000282 R14: 00000000ae000001 R15: 0000000000000001 [ 205.799024] FS: 0000000000000000(0000) GS:ffff9a0d0f300000(0000) knlGS:0000000000000000 [ 205.799028] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 205.799031] CR2: 00007ff6b8311554 CR3: 000000001ac10004 CR4: 00000000001706e0 [ 205.799033] Call Trace: [ 205.799035] <TASK> [ 205.799038] ? ax25_dev_device_down+0xd9/0x1b0 [ax25] [ 205.799047] ? ax25_device_event+0x9f/0x270 [ax25] [ 205.799055] ? raw_notifier_call_chain+0x49/0x60 [ 205.799060] ? call_netdevice_notifiers_info+0x52/0xa0 [ 205.799065] ? dev_close_many+0xc8/0x120 [ 205.799070] ? unregister_netdevice_many+0x13d/0x890 [ 205.799073] ? unregister_netdevice_queue+0x90/0xe0 [ 205.799076] ? unregister_netdev+0x1d/0x30 [ 205.799080] ? mkiss_close+0x7c/0xc0 [mkiss] [ 205.799084] ? tty_ldisc_close+0x2e/0x40 [ 205.799089] ? tty_ldisc_hangup+0x137/0x210 [ 205.799092] ? __tty_hangup.part.0+0x208/0x350 [ 205.799098] ? tty_vhangup+0x15/0x20 [ 205.799103] ? pty_close+0x127/0x160 [ 205.799108] ? tty_release+0x139/0x5e0 [ 205.799112] ? __fput+0x9f/0x260 [ 205.799118] ax25_dev_device_down+0xd9/0x1b0 [ax25] [ 205.799126] ax25_device_event+0x9f/0x270 [ax25] [ 205.799135] raw_notifier_call_chain+0x49/0x60 [ 205.799140] call_netdevice_notifiers_info+0x52/0xa0 [ 205.799146] dev_close_many+0xc8/0x120 [ 205.799152] unregister_netdevice_many+0x13d/0x890 [ 205.799157] unregister_netdevice_queue+0x90/0xe0 [ 205.799161] unregister_netdev+0x1d/0x30 [ 205.799165] mkiss_close+0x7c/0xc0 [mkiss] [ 205.799170] tty_ldisc_close+0x2e/0x40 [ 205.799173] tty_ldisc_hangup+0x137/0x210 [ 205.799178] __tty_hangup.part.0+0x208/0x350 [ 205.799184] tty_vhangup+0x15/0x20 [ 205.799188] pty_close+0x127/0x160 [ 205.799193] tty_release+0x139/0x5e0 [ 205.799199] __fput+0x9f/0x260 [ 205.799203] ____fput+0xe/0x10 [ 205.799208] task_work_run+0x64/0xa0 [ 205.799213] do_exit+0x33b/0xab0 [ 205.799217] ? __handle_mm_fault+0xc4f/0x15f0 [ 205.799224] do_group_exit+0x35/0xa0 [ 205.799228] __x64_sys_exit_group+0x18/0x20 [ 205.799232] do_syscall_64+0x5c/0x80 [ 205.799238] ? handle_mm_fault+0xba/0x290 [ 205.799242] ? debug_smp_processor_id+0x17/0x20 [ 205.799246] ? fpregs_assert_state_consistent+0x26/0x50 [ 205.799251] ? exit_to_user_mode_prepare+0x49/0x190 [ 205.799256] ? irqentry_exit_to_user_mode+0x9/0x20 [ 205.799260] ? irqentry_exit+0x33/0x40 [ 205.799263] ? exc_page_fault+0x87/0x170 [ 205.799268] ? asm_exc_page_fault+0x8/0x30 [ 205.799273] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.799277] RIP: 0033:0x7ff6b80eaca1 [ 205.799281] Code: Unable to access opcode bytes at RIP 0x7ff6b80eac77. [ 205.799283] RSP: 002b:00007fff6dfd4738 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 205.799287] RAX: ffffffffffffffda RBX: 00007ff6b8215a00 RCX: 00007ff6b80eaca1 [ 205.799290] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001 [ 205.799293] RBP: 0000000000000001 R08: ffffffffffffff80 R09: 0000000000000028 [ 205.799295] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff6b8215a00 [ 205.799298] R13: 0000000000000000 R14: 00007ff6b821aee8 R15: 00007ff6b821af00 [ 205.799304] </TASK> Fixes: feef318c855a ("ax25: fix UAF bugs of net_device caused by rebinding operation") Reported-by: Bernard F6BVP <f6bvp@free.fr> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20220728051821.3160118-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-5/+28
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-15net: ax25: Fix deadlock caused by skb_recv_datagram in ax25_recvmsgDuoming Zhou1-5/+28
The skb_recv_datagram() in ax25_recvmsg() will hold lock_sock and block until it receives a packet from the remote. If the client doesn`t connect to server and calls read() directly, it will not receive any packets forever. As a result, the deadlock will happen. The fail log caused by deadlock is shown below: [ 369.606973] INFO: task ax25_deadlock:157 blocked for more than 245 seconds. [ 369.608919] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.613058] Call Trace: [ 369.613315] <TASK> [ 369.614072] __schedule+0x2f9/0xb20 [ 369.615029] schedule+0x49/0xb0 [ 369.615734] __lock_sock+0x92/0x100 [ 369.616763] ? destroy_sched_domains_rcu+0x20/0x20 [ 369.617941] lock_sock_nested+0x6e/0x70 [ 369.618809] ax25_bind+0xaa/0x210 [ 369.619736] __sys_bind+0xca/0xf0 [ 369.620039] ? do_futex+0xae/0x1b0 [ 369.620387] ? __x64_sys_futex+0x7c/0x1c0 [ 369.620601] ? fpregs_assert_state_consistent+0x19/0x40 [ 369.620613] __x64_sys_bind+0x11/0x20 [ 369.621791] do_syscall_64+0x3b/0x90 [ 369.622423] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 369.623319] RIP: 0033:0x7f43c8aa8af7 [ 369.624301] RSP: 002b:00007f43c8197ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 [ 369.625756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f43c8aa8af7 [ 369.626724] RDX: 0000000000000010 RSI: 000055768e2021d0 RDI: 0000000000000005 [ 369.628569] RBP: 00007f43c8197f00 R08: 0000000000000011 R09: 00007f43c8198700 [ 369.630208] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff845e6afe [ 369.632240] R13: 00007fff845e6aff R14: 00007f43c8197fc0 R15: 00007f43c8198700 This patch replaces skb_recv_datagram() with an open-coded variant of it releasing the socket lock before the __skb_wait_for_more_packets() call and re-acquiring it after such call in order that other functions that need socket lock could be executed. what's more, the socket lock will be released only when recvmsg() will block and that should produce nicer overall behavior. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Suggested-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reported-by: Thomas Habets <thomas@@habets.se> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-09net: rename reference+tracking helpersJakub Kicinski1-3/+4
Netdev reference helpers have a dev_ prefix for historic reasons. Renaming the old helpers would be too much churn but we can rename the tracking ones which are relatively recent and should be the default for new code. Rename: dev_hold_track() -> netdev_hold() dev_put_track() -> netdev_put() dev_replace_track() -> netdev_ref_replace() Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-02ax25: Fix ax25 session cleanup problemsDuoming Zhou1-10/+17
There are session cleanup problems in ax25_release() and ax25_disconnect(). If we setup a session and then disconnect, the disconnected session is still in "LISTENING" state that is shown below. Active AX.25 sockets Dest Source Device State Vr/Vs Send-Q Recv-Q DL9SAU-4 DL9SAU-3 ??? LISTENING 000/000 0 0 DL9SAU-3 DL9SAU-4 ??? LISTENING 000/000 0 0 The first reason is caused by del_timer_sync() in ax25_release(). The timers of ax25 are used for correct session cleanup. If we use ax25_release() to close ax25 sessions and ax25_dev is not null, the del_timer_sync() functions in ax25_release() will execute. As a result, the sessions could not be cleaned up correctly, because the timers have stopped. In order to solve this problem, this patch adds a device_up flag in ax25_dev in order to judge whether the device is up. If there are sessions to be cleaned up, the del_timer_sync() in ax25_release() will not execute. What's more, we add ax25_cb_del() in ax25_kill_by_device(), because the timers have been stopped and there are no functions that could delete ax25_cb if we do not call ax25_release(). Finally, we reorder the position of ax25_list_lock in ax25_cb_del() in order to synchronize among different functions that call ax25_cb_del(). The second reason is caused by improper check in ax25_disconnect(). The incoming ax25 sessions which ax25->sk is null will close heartbeat timer, because the check "if(!ax25->sk || ..)" is satisfied. As a result, the session could not be cleaned up properly. In order to solve this problem, this patch changes the improper check to "if(ax25->sk && ..)" in ax25_disconnect(). What`s more, the ax25_disconnect() may be called twice, which is not necessary. For example, ax25_kill_by_device() calls ax25_disconnect() and sets ax25->state to AX25_STATE_0, but ax25_release() calls ax25_disconnect() again. In order to solve this problem, this patch add a check in ax25_release(). If the flag of ax25->sk equals to SOCK_DEAD, the ax25_disconnect() in ax25_release() should not be executed. Fixes: 82e31755e55f ("ax25: Fix UAF bugs in ax25 timers") Fixes: 8a367e74c012 ("ax25: Fix segfault after sock connection timeout") Reported-and-tested-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20220530152158.108619-1-duoming@zju.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-04-06net: remove noblock parameter from skb_recv_datagram()Oliver Hartkopp1-2/+1
skb_recv_datagram() has two parameters 'flags' and 'noblock' that are merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)' As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags' into 'flags' and 'noblock' with finally obsolete bit operations like this: skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc); And this is not even done consistently with the 'flags' parameter. This patch removes the obsolete and costly splitting into two parameters and only performs bit operations when really needed on the caller side. One missing conversion thankfully reported by kernel test robot. I missed to enable kunit tests to build the mctp code. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-29ax25: Fix UAF bugs in ax25 timersDuoming Zhou1-0/+5
There are race conditions that may lead to UAF bugs in ax25_heartbeat_expiry(), ax25_t1timer_expiry(), ax25_t2timer_expiry(), ax25_t3timer_expiry() and ax25_idletimer_expiry(), when we call ax25_release() to deallocate ax25_dev. One of the UAF bugs caused by ax25_release() is shown below: (Thread 1) | (Thread 2) ax25_dev_device_up() //(1) | ... | ax25_kill_by_device() ax25_bind() //(2) | ax25_connect() | ... ax25_std_establish_data_link() | ax25_start_t1timer() | ax25_dev_device_down() //(3) mod_timer(&ax25->t1timer,..) | | ax25_release() (wait a time) | ... | ax25_dev_put(ax25_dev) //(4)FREE ax25_t1timer_expiry() | ax25->ax25_dev->values[..] //USE| ... ... | We increase the refcount of ax25_dev in position (1) and (2), and decrease the refcount of ax25_dev in position (3) and (4). The ax25_dev will be freed in position (4) and be used in ax25_t1timer_expiry(). The fail log is shown below: ============================================================== [ 106.116942] BUG: KASAN: use-after-free in ax25_t1timer_expiry+0x1c/0x60 [ 106.116942] Read of size 8 at addr ffff88800bda9028 by task swapper/0/0 [ 106.116942] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-06123-g0905eec574 [ 106.116942] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-14 [ 106.116942] Call Trace: ... [ 106.116942] ax25_t1timer_expiry+0x1c/0x60 [ 106.116942] call_timer_fn+0x122/0x3d0 [ 106.116942] __run_timers.part.0+0x3f6/0x520 [ 106.116942] run_timer_softirq+0x4f/0xb0 [ 106.116942] __do_softirq+0x1c2/0x651 ... This patch adds del_timer_sync() in ax25_release(), which could ensure that all timers stop before we deallocate ax25_dev. Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-03-29ax25: fix UAF bug in ax25_send_control()Duoming Zhou1-4/+4
There are UAF bugs in ax25_send_control(), when we call ax25_release() to deallocate ax25_dev. The possible race condition is shown below: (Thread 1) | (Thread 2) ax25_dev_device_up() //(1) | | ax25_kill_by_device() ax25_bind() //(2) | ax25_connect() | ... ax25->state = AX25_STATE_1 | ... | ax25_dev_device_down() //(3) (Thread 3) ax25_release() | ax25_dev_put() //(4) FREE | case AX25_STATE_1: | ax25_send_control() | alloc_skb() //USE | The refcount of ax25_dev increases in position (1) and (2), and decreases in position (3) and (4). The ax25_dev will be freed before dereference sites in ax25_send_control(). The following is part of the report: [ 102.297448] BUG: KASAN: use-after-free in ax25_send_control+0x33/0x210 [ 102.297448] Read of size 8 at addr ffff888009e6e408 by task ax25_close/602 [ 102.297448] Call Trace: [ 102.303751] ax25_send_control+0x33/0x210 [ 102.303751] ax25_release+0x356/0x450 [ 102.305431] __sock_release+0x6d/0x120 [ 102.305431] sock_close+0xf/0x20 [ 102.305431] __fput+0x11f/0x420 [ 102.305431] task_work_run+0x86/0xd0 [ 102.307130] get_signal+0x1075/0x1220 [ 102.308253] arch_do_signal_or_restart+0x1df/0xc00 [ 102.308253] exit_to_user_mode_prepare+0x150/0x1e0 [ 102.308253] syscall_exit_to_user_mode+0x19/0x50 [ 102.308253] do_syscall_64+0x48/0x90 [ 102.308253] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 102.308253] RIP: 0033:0x405ae7 This patch defers the free operation of ax25_dev and net_device after all corresponding dereference sites in ax25_release() to avoid UAF. Fixes: 9fd75b66b8f6 ("ax25: Fix refcount leaks caused by ax25_cb_del()") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-03-21ax25: Fix NULL pointer dereferences in ax25 timersDuoming Zhou1-2/+2
The previous commit 7ec02f5ac8a5 ("ax25: fix NPD bug in ax25_disconnect") move ax25_disconnect into lock_sock() in order to prevent NPD bugs. But there are race conditions that may lead to null pointer dereferences in ax25_heartbeat_expiry(), ax25_t1timer_expiry(), ax25_t2timer_expiry(), ax25_t3timer_expiry() and ax25_idletimer_expiry(), when we use ax25_kill_by_device() to detach the ax25 device. One of the race conditions that cause null pointer dereferences can be shown as below: (Thread 1) | (Thread 2) ax25_connect() | ax25_std_establish_data_link() | ax25_start_t1timer() | mod_timer(&ax25->t1timer,..) | | ax25_kill_by_device() (wait a time) | ... | s->ax25_dev = NULL; //(1) ax25_t1timer_expiry() | ax25->ax25_dev->values[..] //(2)| ... ... | We set null to ax25_cb->ax25_dev in position (1) and dereference the null pointer in position (2). The corresponding fail log is shown below: =============================================================== BUG: kernel NULL pointer dereference, address: 0000000000000050 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.17.0-rc6-00794-g45690b7d0 RIP: 0010:ax25_t1timer_expiry+0x12/0x40 ... Call Trace: call_timer_fn+0x21/0x120 __run_timers.part.0+0x1ca/0x250 run_timer_softirq+0x2c/0x60 __do_softirq+0xef/0x2f3 irq_exit_rcu+0xb6/0x100 sysvec_apic_timer_interrupt+0xa2/0xd0 ... This patch moves ax25_disconnect() before s->ax25_dev = NULL and uses del_timer_sync() to delete timers in ax25_disconnect(). If ax25_disconnect() is called by ax25_kill_by_device() or ax25->ax25_dev is NULL, the reason in ax25_disconnect() will be equal to ENETUNREACH, it will wait all timers to stop before we set null to s->ax25_dev in ax25_kill_by_device(). Fixes: 7ec02f5ac8a5 ("ax25: fix NPD bug in ax25_disconnect") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-21ax25: Fix refcount leaks caused by ax25_cb_del()Duoming Zhou1-3/+11
The previous commit d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") and commit feef318c855a ("ax25: fix UAF bugs of net_device caused by rebinding operation") increase the refcounts of ax25_dev and net_device in ax25_bind() and decrease the matching refcounts in ax25_kill_by_device() in order to prevent UAF bugs, but there are reference count leaks. The root cause of refcount leaks is shown below: (Thread 1) | (Thread 2) ax25_bind() | ... | ax25_addr_ax25dev() | ax25_dev_hold() //(1) | ... | dev_hold_track() //(2) | ... | ax25_destroy_socket() | ax25_cb_del() | ... | hlist_del_init() //(3) | | (Thread 3) | ax25_kill_by_device() | ... | ax25_for_each(s, &ax25_list) { | if (s->ax25_dev == ax25_dev) //(4) | ... | Firstly, we use ax25_bind() to increase the refcount of ax25_dev in position (1) and increase the refcount of net_device in position (2). Then, we use ax25_cb_del() invoked by ax25_destroy_socket() to delete ax25_cb in hlist in position (3) before calling ax25_kill_by_device(). Finally, the decrements of refcounts in ax25_kill_by_device() will not be executed, because no s->ax25_dev equals to ax25_dev in position (4). This patch adds decrements of refcounts in ax25_release() and use lock_sock() to do synchronization. If refcounts decrease in ax25_release(), the decrements of refcounts in ax25_kill_by_device() will not be executed and vice versa. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Fixes: 87563a043cef ("ax25: fix reference count leaks of ax25_dev") Fixes: feef318c855a ("ax25: fix UAF bugs of net_device caused by rebinding operation") Reported-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-09ax25: Fix NULL pointer dereference in ax25_kill_by_deviceDuoming Zhou1-0/+7
When two ax25 devices attempted to establish connection, the requester use ax25_create(), ax25_bind() and ax25_connect() to initiate connection. The receiver use ax25_rcv() to accept connection and use ax25_create_cb() in ax25_rcv() to create ax25_cb, but the ax25_cb->sk is NULL. When the receiver is detaching, a NULL pointer dereference bug caused by sock_hold(sk) in ax25_kill_by_device() will happen. The corresponding fail log is shown below: =============================================================== BUG: KASAN: null-ptr-deref in ax25_device_event+0xfd/0x290 Call Trace: ... ax25_device_event+0xfd/0x290 raw_notifier_call_chain+0x5e/0x70 dev_close_many+0x174/0x220 unregister_netdevice_many+0x1f7/0xa60 unregister_netdevice_queue+0x12f/0x170 unregister_netdev+0x13/0x20 mkiss_close+0xcd/0x140 tty_ldisc_release+0xc0/0x220 tty_release_struct+0x17/0xa0 tty_release+0x62d/0x670 ... This patch add condition check in ax25_kill_by_device(). If s->sk is NULL, it will goto if branch to kill device. Fixes: 4e0f718daf97 ("ax25: improve the incomplete fix to avoid UAF and NPD bugs") Reported-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-09ax25: fix UAF bugs of net_device caused by rebinding operationDuoming Zhou1-1/+4
The ax25_kill_by_device() will set s->ax25_dev = NULL and call ax25_disconnect() to change states of ax25_cb and sock, if we call ax25_bind() before ax25_kill_by_device(). However, if we call ax25_bind() again between the window of ax25_kill_by_device() and ax25_dev_device_down(), the values and states changed by ax25_kill_by_device() will be reassigned. Finally, ax25_dev_device_down() will deallocate net_device. If we dereference net_device in syscall functions such as ax25_release(), ax25_sendmsg(), ax25_getsockopt(), ax25_getname() and ax25_info_show(), a UAF bug will occur. One of the possible race conditions is shown below: (USE) | (FREE) ax25_bind() | | ax25_kill_by_device() ax25_bind() | ax25_connect() | ... | ax25_dev_device_down() | ... | dev_put_track(dev, ...) //FREE ax25_release() | ... ax25_send_control() | alloc_skb() //USE | the corresponding fail log is shown below: =============================================================== BUG: KASAN: use-after-free in ax25_send_control+0x43/0x210 ... Call Trace: ... ax25_send_control+0x43/0x210 ax25_release+0x2db/0x3b0 __sock_release+0x6d/0x120 sock_close+0xf/0x20 __fput+0x11f/0x420 ... Allocated by task 1283: ... __kasan_kmalloc+0x81/0xa0 alloc_netdev_mqs+0x5a/0x680 mkiss_open+0x6c/0x380 tty_ldisc_open+0x55/0x90 ... Freed by task 1969: ... kfree+0xa3/0x2c0 device_release+0x54/0xe0 kobject_put+0xa5/0x120 tty_ldisc_kill+0x3e/0x80 ... In order to fix these UAF bugs caused by rebinding operation, this patch adds dev_hold_track() into ax25_bind() and corresponding dev_put_track() into ax25_kill_by_device(). Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-09ax25: fix NPD bug in ax25_disconnectDuoming Zhou1-1/+1
The ax25_disconnect() in ax25_kill_by_device() is not protected by any locks, thus there is a race condition between ax25_disconnect() and ax25_destroy_socket(). when ax25->sk is assigned as NULL by ax25_destroy_socket(), a NULL pointer dereference bug will occur if site (1) or (2) dereferences ax25->sk. ax25_kill_by_device() | ax25_release() ax25_disconnect() | ax25_destroy_socket() ... | if(ax25->sk != NULL) | ... ... | ax25->sk = NULL; bh_lock_sock(ax25->sk); //(1) | ... ... | bh_unlock_sock(ax25->sk); //(2)| This patch moves ax25_disconnect() into lock_sock(), which can synchronize with ax25_destroy_socket() in ax25_release(). Fail log: =============================================================== BUG: kernel NULL pointer dereference, address: 0000000000000088 ... RIP: 0010:_raw_spin_lock+0x7e/0xd0 ... Call Trace: ax25_disconnect+0xf6/0x220 ax25_device_event+0x187/0x250 raw_notifier_call_chain+0x5e/0x70 dev_close_many+0x17d/0x230 rollback_registered_many+0x1f1/0x950 unregister_netdevice_queue+0x133/0x200 unregister_netdev+0x13/0x20 ... Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-03ax25: fix reference count leaks of ax25_devDuoming Zhou1-4/+8
The previous commit d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") introduces refcount into ax25_dev, but there are reference leak paths in ax25_ctl_ioctl(), ax25_fwd_ioctl(), ax25_rt_add(), ax25_rt_del() and ax25_rt_opt(). This patch uses ax25_dev_put() and adjusts the position of ax25_addr_ax25dev() to fix reference cout leaks of ax25_dev. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20220203150811.42256-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-28ax25: add refcount in ax25_dev to avoid UAF bugsDuoming Zhou1-0/+2
If we dereference ax25_dev after we call kfree(ax25_dev) in ax25_dev_device_down(), it will lead to concurrency UAF bugs. There are eight syscall functions suffer from UAF bugs, include ax25_bind(), ax25_release(), ax25_connect(), ax25_ioctl(), ax25_getname(), ax25_sendmsg(), ax25_getsockopt() and ax25_info_show(). One of the concurrency UAF can be shown as below: (USE) | (FREE) | ax25_device_event | ax25_dev_device_down ax25_bind | ... ... | kfree(ax25_dev) ax25_fillin_cb() | ... ax25_fillin_cb_from_dev() | ... | The root cause of UAF bugs is that kfree(ax25_dev) in ax25_dev_device_down() is not protected by any locks. When ax25_dev, which there are still pointers point to, is released, the concurrency UAF bug will happen. This patch introduces refcount into ax25_dev in order to guarantee that there are no pointers point to it when ax25_dev is released. Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-28ax25: improve the incomplete fix to avoid UAF and NPD bugsDuoming Zhou1-3/+6
The previous commit 1ade48d0c27d ("ax25: NPD bug when detaching AX25 device") introduce lock_sock() into ax25_kill_by_device to prevent NPD bug. But the concurrency NPD or UAF bug will occur, when lock_sock() or release_sock() dereferences the ax25_cb->sock. The NULL pointer dereference bug can be shown as below: ax25_kill_by_device() | ax25_release() | ax25_destroy_socket() | ax25_cb_del() ... | ... | ax25->sk=NULL; lock_sock(s->sk); //(1) | s->ax25_dev = NULL; | ... release_sock(s->sk); //(2) | ... | The root cause is that the sock is set to null before dereference site (1) or (2). Therefore, this patch extracts the ax25_cb->sock in advance, and uses ax25_list_lock to protect it, which can synchronize with ax25_cb_del() and ensure the value of sock is not null before dereference sites. The concurrency UAF bug can be shown as below: ax25_kill_by_device() | ax25_release() | ax25_destroy_socket() ... | ... | sock_put(sk); //FREE lock_sock(s->sk); //(1) | s->ax25_dev = NULL; | ... release_sock(s->sk); //(2) | ... | The root cause is that the sock is released before dereference site (1) or (2). Therefore, this patch uses sock_hold() to increase the refcount of sock and uses ax25_list_lock to protect it, which can synchronize with ax25_cb_del() in ax25_destroy_socket() and ensure the sock wil not be released before dereference sites. Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-07ax25: uninitialized variable in ax25_setsockopt()Dan Carpenter1-5/+5
The "opt" variable is unsigned long but we only copy 4 bytes from the user so the lower 4 bytes are uninitialized. I have changed the integer overflow checks from ULONG to UINT as well. This is a slight API change but I don't expect it to break anything. Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-18ax25: NPD bug when detaching AX25 deviceLin Ma1-1/+3
The existing cleanup routine implementation is not well synchronized with the syscall routine. When a device is detaching, below race could occur. static int ax25_sendmsg(...) { ... lock_sock() ax25 = sk_to_ax25(sk); if (ax25->ax25_dev == NULL) // CHECK ... ax25_queue_xmit(skb, ax25->ax25_dev->dev); // USE ... } static void ax25_kill_by_device(...) { ... if (s->ax25_dev == ax25_dev) { s->ax25_dev = NULL; ... } Other syscall functions like ax25_getsockopt, ax25_getname, ax25_info_show also suffer from similar races. To fix them, this patch introduce lock_sock() into ax25_kill_by_device in order to guarantee that the nullify action in cleanup routine cannot proceed when another socket request is pending. Signed-off-by: Hanjie Wu <nagi@zju.edu.cn> Signed-off-by: Lin Ma <linma@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-13ax25: constify dev_addr passingJakub Kicinski1-1/+1
In preparation for netdev->dev_addr being constant make all relevant arguments in AX25 constant. Modify callers as well (netrom, rose). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-03-10net: ax25: Fix fall-through warnings for ClangGustavo A. R. Silva1-0/+1
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-2/+8
The UDP reuseport conflict was a little bit tricky. The net-next code, via bpf-next, extracted the reuseport handling into a helper so that the BPF sk lookup code could invoke it. At the same time, the logic for reuseport handling of unconnected sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace which changed the logic to carry on the reuseport result into the rest of the lookup loop if we do not return immediately. This requires moving the reuseport_has_conns() logic into the callers. While we are here, get rid of inline directives as they do not belong in foo.c files. The other changes were cases of more straightforward overlapping modifications. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net: pass a sockptr_t into ->setsockoptChristoph Hellwig1-3/+3
Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154] Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23AX.25: Prevent integer overflows in connect and sendmsgDan Carpenter1-1/+4
We recently added some bounds checking in ax25_connect() and ax25_sendmsg() and we so we removed the AX25_MAX_DIGIS checks because they were no longer required. Unfortunately, I believe they are required to prevent integer overflows so I have added them back. Fixes: 8885bb0621f0 ("AX.25: Prevent out-of-bounds read in ax25_sendmsg()") Fixes: 2f2a7ffad5c6 ("AX.25: Fix out-of-bounds read in ax25_connect()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22AX.25: Prevent out-of-bounds read in ax25_sendmsg()Peilin Ye1-1/+2
Checks on `addr_len` and `usax->sax25_ndigis` are insufficient. ax25_sendmsg() can go out of bounds when `usax->sax25_ndigis` equals to 7 or 8. Fix it. It is safe to remove `usax->sax25_ndigis > AX25_MAX_DIGIS`, since `addr_len` is guaranteed to be less than or equal to `sizeof(struct full_sockaddr_ax25)` Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22AX.25: Fix out-of-bounds read in ax25_connect()Peilin Ye1-1/+3
Checks on `addr_len` and `fsa->fsa_ax25.sax25_ndigis` are insufficient. ax25_connect() can go out of bounds when `fsa->fsa_ax25.sax25_ndigis` equals to 7 or 8. Fix it. This issue has been reported as a KMSAN uninit-value bug, because in such a case, ax25_connect() reaches into the uninitialized portion of the `struct sockaddr_storage` statically allocated in __sys_connect(). It is safe to remove `fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS` because `addr_len` is guaranteed to be less than or equal to `sizeof(struct full_sockaddr_ax25)`. Reported-by: syzbot+c82752228ed975b0a623@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=55ef9d629f3b3d7d70b69558015b63b48d01af66 Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-20ax25: fix setsockopt(SO_BINDTODEVICE)Eric Dumazet1-2/+4
syzbot was able to trigger this trace [1], probably by using a zero optlen. While we are at it, cap optlen to IFNAMSIZ - 1 instead of IFNAMSIZ. [1] BUG: KMSAN: uninit-value in strnlen+0xf9/0x170 lib/string.c:569 CPU: 0 PID: 8807 Comm: syz-executor483 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 strnlen+0xf9/0x170 lib/string.c:569 dev_name_hash net/core/dev.c:207 [inline] netdev_name_node_lookup net/core/dev.c:277 [inline] __dev_get_by_name+0x75/0x2b0 net/core/dev.c:778 ax25_setsockopt+0xfa3/0x1170 net/ax25/af_ax25.c:654 __compat_sys_setsockopt+0x4ed/0x910 net/compat.c:403 __do_compat_sys_setsockopt net/compat.c:413 [inline] __se_compat_sys_setsockopt+0xdd/0x100 net/compat.c:410 __ia32_compat_sys_setsockopt+0x62/0x80 net/compat.c:410 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f57dd9 Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffae8c1c EFLAGS: 00000217 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000101 RDX: 0000000000000019 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Local variable ----devname@ax25_setsockopt created at: ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09net: Make sock protocol value checks more specificMat Martineau1-1/+1
SK_PROTOCOL_MAX is only used in two places, for DECNet and AX.25. The limits have more to do with the those protocol definitions than they do with the data type of sk_protocol, so remove SK_PROTOCOL_MAX and use U8_MAX directly. Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06net: use helpers to change sk_ack_backlogEric Dumazet1-1/+1
Writers are holding a lock, but many readers do not. Following patch will add appropriate barriers in sk_acceptq_removed() and sk_acceptq_added(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-24ax25: enforce CAP_NET_RAW for raw socketsOri Nimron1-0/+2
When creating a raw AF_AX25 socket, CAP_NET_RAW needs to be checked first. Signed-off-by: Ori Nimron <orinimron123@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-4/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-21net: ax25: fix misuse of %xFuqian Huang1-2/+2
Pointers should be printed with %p or %px rather than cast to long type and printed with %8.8lx. Change %8.8lx to %p to print the pointer. Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-19net: rework SIOCGSTAMP ioctl handlingArnd Bergmann1-8/+1
The SIOCGSTAMP/SIOCGSTAMPNS ioctl commands are implemented by many socket protocol handlers, and all of those end up calling the same sock_get_timestamp()/sock_get_timestampns() helper functions, which results in a lot of duplicate code. With the introduction of 64-bit time_t on 32-bit architectures, this gets worse, as we then need four different ioctl commands in each socket protocol implementation. To simplify that, let's add a new .gettstamp() operation in struct proto_ops, and move ioctl implementation into the common sock_ioctl()/compat_sock_ioctl_trans() functions that these all go through. We can reuse the sock_get_timestamp() implementation, but generalize it so it can deal with both native and compat mode, as well as timeval and timespec structures. Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/lkml/CAK8P3a038aDQQotzua_QtKGhq8O9n+rdiz2=WDCp82ys8eUT+A@mail.gmail.com/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-30ax25: fix a use-after-free in ax25_fillin_cb()Cong Wang1-2/+9
There are multiple issues here: 1. After freeing dev->ax25_ptr, we need to set it to NULL otherwise we may use a dangling pointer. 2. There is a race between ax25_setsockopt() and device notifier as reported by syzbot. Close it by holding RTNL lock. 3. We need to test if dev->ax25_ptr is NULL before using it. Reported-and-tested-by: syzbot+ae6bb869cbed29b29040@syzkaller.appspotmail.com Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLLLinus Torvalds1-1/+1
The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-04Merge branch 'work.aio-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-05-26net: convert datagram_poll users tp ->poll_maskChristoph Hellwig1-1/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-16proc: introduce proc_create_seq{,_data}Christoph Hellwig1-17/+4
Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-03-26net: Use octal not symbolic permissionsJoe Perches1-3/+3
Prefer the direct use of octal for permissions. Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace and some typing. Miscellanea: o Whitespace neatening around these conversions. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-12net: make getname() functions return length rather than use int* parameterDenys Vlasenko1-2/+2
Changes since v1: Added changes in these files: drivers/infiniband/hw/usnic/usnic_transport.c drivers/staging/lustre/lnet/lnet/lib-socket.c drivers/target/iscsi/iscsi_target_login.c drivers/vhost/net.c fs/dlm/lowcomms.c fs/ocfs2/cluster/tcp.c security/tomoyo/network.c Before: All these functions either return a negative error indicator, or store length of sockaddr into "int *socklen" parameter and return zero on success. "int *socklen" parameter is awkward. For example, if caller does not care, it still needs to provide on-stack storage for the value it does not need. None of the many FOO_getname() functions of various protocols ever used old value of *socklen. They always just overwrite it. This change drops this parameter, and makes all these functions, on success, return length of sockaddr. It's always >= 0 and can be differentiated from an error. Tests in callers are changed from "if (err)" to "if (err < 0)", where needed. rpc_sockname() lost "int buflen" parameter, since its only use was to be passed to kernel_getsockname() as &buflen and subsequently not used in any way. Userspace API is not changed. text data bss dec hex filename 30108430 2633624 873672 33615726 200ef6e vmlinux.before.o 30108109 2633612 873672 33615393 200ee21 vmlinux.o Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: David S. Miller <davem@davemloft.net> CC: linux-kernel@vger.kernel.org CC: netdev@vger.kernel.org CC: linux-bluetooth@vger.kernel.org CC: linux-decnet-user@lists.sourceforge.net CC: linux-wireless@vger.kernel.org CC: linux-rdma@vger.kernel.org CC: linux-sctp@vger.kernel.org CC: linux-nfs@vger.kernel.org CC: linux-x25@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16net: delete /proc THIS_MODULE referencesAlexey Dobriyan1-1/+0
/proc has been ignoring struct file_operations::owner field for 10 years. Specifically, it started with commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba ("Fix rmmod/read/write races in /proc entries"). Notice the chunk where inode->i_fop is initialized with proxy struct file_operations for regular files: - if (de->proc_fops) - inode->i_fop = de->proc_fops; + if (de->proc_fops) { + if (S_ISREG(inode->i_mode)) + inode->i_fop = &proc_reg_file_ops; + else + inode->i_fop = de->proc_fops; + } VFS stopped pinning module at this point. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-25net: ax25: Convert timers to use timer_setup()Kees Cook1-4/+3
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Joerg Reuter <jreuter@yaina.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-hams@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04net, ax25: convert ax25_cb.refcount from atomic_t to refcount_tReshetova, Elena1-1/+1
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16networking: make skb_push & __skb_push return void pointersJohannes Berg1-1/+1
It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) @@ expression SKB, LEN; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; @@ - fn(SKB, LEN)[0] + *(u8 *)fn(SKB, LEN) Note that the last part there converts from push(...)[0] to the more idiomatic *(u8 *)push(...). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09net: Work around lockdep limitation in sockets that use socketsDavid Howells1-1/+2
Lockdep issues a circular dependency warning when AFS issues an operation through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem. The theory lockdep comes up with is as follows: (1) If the pagefault handler decides it needs to read pages from AFS, it calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but creating a call requires the socket lock: mmap_sem must be taken before sk_lock-AF_RXRPC (2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind() binds the underlying UDP socket whilst holding its socket lock. inet_bind() takes its own socket lock: sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET (3) Reading from a TCP socket into a userspace buffer might cause a fault and thus cause the kernel to take the mmap_sem, but the TCP socket is locked whilst doing this: sk_lock-AF_INET must be taken before mmap_sem However, lockdep's theory is wrong in this instance because it deals only with lock classes and not individual locks. The AF_INET lock in (2) isn't really equivalent to the AF_INET lock in (3) as the former deals with a socket entirely internal to the kernel that never sees userspace. This is a limitation in the design of lockdep. Fix the general case by: (1) Double up all the locking keys used in sockets so that one set are used if the socket is created by userspace and the other set is used if the socket is created by the kernel. (2) Store the kern parameter passed to sk_alloc() in a variable in the sock struct (sk_kern_sock). This informs sock_lock_init(), sock_init_data() and sk_clone_lock() as to the lock keys to be used. Note that the child created by sk_clone_lock() inherits the parent's kern setting. (3) Add a 'kern' parameter to ->accept() that is analogous to the one passed in to ->create() that distinguishes whether kernel_accept() or sys_accept4() was the caller and can be passed to sk_alloc(). Note that a lot of accept functions merely dequeue an already allocated socket. I haven't touched these as the new socket already exists before we get the parameter. Note also that there are a couple of places where I've made the accepted socket unconditionally kernel-based: irda_accept() rds_rcp_accept_one() tcp_accept_from_sock() because they follow a sock_create_kern() and accept off of that. Whilst creating this, I noticed that lustre and ocfs don't create sockets through sock_create_kern() and thus they aren't marked as for-kernel, though they appear to be internal. I wonder if these should do that so that they use the new set of lock keys. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-1/+1
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-18AX.25: Close socket connection on session completionBasil Gunn1-1/+2
A socket connection made in ax.25 is not closed when session is completed. The heartbeat timer is stopped prematurely and this is where the socket gets closed. Allow heatbeat timer to run to close socket. Symptom occurs in kernels >= 4.2.0 Originally sent 6/15/2016. Resend with distribution list matching scripts/maintainer.pl output. Signed-off-by: Basil Gunn <basil@pacabunga.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-14net: add validation for the socket syscall protocol argumentHannes Frederic Sowa1-0/+3
郭永刚 reported that one could simply crash the kernel as root by using a simple program: int socket_fd; struct sockaddr_in addr; addr.sin_port = 0; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_family = 10; socket_fd = socket(10,3,0x40000000); connect(socket_fd , &addr,16); AF_INET, AF_INET6 sockets actually only support 8-bit protocol identifiers. inet_sock's skc_protocol field thus is sized accordingly, thus larger protocol identifiers simply cut off the higher bits and store a zero in the protocol fields. This could lead to e.g. NULL function pointer because as a result of the cut off inet_num is zero and we call down to inet_autobind, which is NULL for raw sockets. kernel: Call Trace: kernel: [<ffffffff816db90e>] ? inet_autobind+0x2e/0x70 kernel: [<ffffffff816db9a4>] inet_dgram_connect+0x54/0x80 kernel: [<ffffffff81645069>] SYSC_connect+0xd9/0x110 kernel: [<ffffffff810ac51b>] ? ptrace_notify+0x5b/0x80 kernel: [<ffffffff810236d8>] ? syscall_trace_enter_phase2+0x108/0x200 kernel: [<ffffffff81645e0e>] SyS_connect+0xe/0x10 kernel: [<ffffffff81779515>] tracesys_phase2+0x84/0x89 I found no particular commit which introduced this problem. CVE: CVE-2015-8543 Cc: Cong Wang <cwang@twopensource.com> Reported-by: 郭永刚 <guoyonggang@360.cn> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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