kernel/linux.git/include/net, branch v4.14.223

net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending

2021-03-03T17:22:57+00:00

commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream. The icmp{,v6}_send functions make all sorts of use of skb->cb, casting it with IPCB or IP6CB, assuming the skb to have come directly from the inet layer. But when the packet comes from the ndo layer, especially when forwarded, there's no telling what might be in skb->cb at that point. As a result, the icmp sending code risks reading bogus memory contents, which can result in nasty stack overflows such as this one reported by a user: panic+0x108/0x2ea __stack_chk_fail+0x14/0x20 __icmp_send+0x5bd/0x5c0 icmp_ndo_send+0x148/0x160 In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read from it. The optlen parameter there is of particular note, as it can induce writes beyond bounds. There are quite a few ways that can happen in __ip_options_echo. For example: // sptr/skb are attacker-controlled skb bytes sptr = skb_network_header(skb); // dptr/dopt points to stack memory allocated by __icmp_send dptr = dopt->__data; // sopt is the corrupt skb->cb in question if (sopt->rr) { optlen = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data // this now writes potentially attacker-controlled data, over // flowing the stack: memcpy(dptr, sptr+sopt->rr, optlen); } In the icmpv6_send case, the story is similar, but not as dire, as only IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is worse than the iif case, but it is passed to ipv6_find_tlv, which does a bit of bounds checking on the value. This is easy to simulate by doing a `memset(skb->cb, 0x41, sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by good fortune and the rarity of icmp sending from that context that we've avoided reports like this until now. For example, in KASAN: BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0 Write of size 38 at addr ffff888006f1f80e by task ping/89 CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5 Call Trace: dump_stack+0x9a/0xcc print_address_description.constprop.0+0x1a/0x160 __kasan_report.cold+0x20/0x38 kasan_report+0x32/0x40 check_memory_region+0x145/0x1a0 memcpy+0x39/0x60 __ip_options_echo+0xa0e/0x12b0 __icmp_send+0x744/0x1700 Actually, out of the 4 drivers that do this, only gtp zeroed the cb for the v4 case, while the rest did not. So this commit actually removes the gtp-specific zeroing, while putting the code where it belongs in the shared infrastructure of icmp{,v6}_ndo_send. This commit fixes the issue by passing an empty IPCB or IP6CB along to the functions that actually do the work. For the icmp_send, this was already trivial, thanks to __icmp_send providing the plumbing function. For icmpv6_send, this required a tiny bit of refactoring to make it behave like the v4 case, after which it was straight forward. Fixes: a2b78e9b2cac ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs") Reported-by: SinYu Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/ Signed-off-by: Jason A. Donenfeld Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

icmp: introduce helper for nat'd source address in network device context

2021-03-03T17:22:56+00:00

commit 0b41713b606694257b90d61ba7e2712d8457648b upstream. This introduces a helper function to be called only by network drivers that wraps calls to icmp[v6]_send in a conntrack transformation, in case NAT has been used. We don't want to pollute the non-driver path, though, so we introduce this as a helper to be called by places that actually make use of this, as suggested by Florian. Signed-off-by: Jason A. Donenfeld Cc: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix TLP timer not set when CA_STATE changes from DISORDER to OPEN

2021-02-03T22:22:23+00:00

commit 62d9f1a6945ba69c125e548e72a36d203b30596e upstream. Upon receiving a cumulative ACK that changes the congestion state from Disorder to Open, the TLP timer is not set. If the sender is app-limited, it can only wait for the RTO timer to expire and retransmit. The reason for this is that the TLP timer is set before the congestion state changes in tcp_ack(), so we delay the time point of calling tcp_set_xmit_timer() until after tcp_fastretrans_alert() returns and remove the FLAG_SET_XMIT_TIMER from ack_flag when the RACK reorder timer is set. This commit has two additional benefits: 1) Make sure to reset RTO according to RFC6298 when receiving ACK, to avoid spurious RTO caused by RTO timer early expires. 2) Reduce the xmit timer reschedule once per ACK when the RACK reorder timer is set. Fixes: df92c8394e6e ("tcp: fix xmit timer to only be reset if data ACKed/SACKed") Link: https://lore.kernel.org/netdev/1611311242-6675-1-git-send-email-yangpc@wangsu.com Signed-off-by: Pengcheng Yang Acked-by: Neal Cardwell Acked-by: Yuchung Cheng Cc: Eric Dumazet Link: https://lore.kernel.org/r/1611464834-23030-1-git-send-email-yangpc@wangsu.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: sched: prevent invalid Scell_log shift count

2021-01-12T19:09:09+00:00

[ Upstream commit bd1248f1ddbc48b0c30565fce897a3b6423313b8 ] Check Scell_log shift size in red_check_params() and modify all callers of red_check_params() to pass Scell_log. This prevents a shift out-of-bounds as detected by UBSAN: UBSAN: shift-out-of-bounds in ./include/net/red.h:252:22 shift exponent 72 is too large for 32-bit type 'int' Fixes: 8afa10cbe281 ("net_sched: red: Avoid illegal values") Signed-off-by: Randy Dunlap Reported-by: syzbot+97c5bd9cc81eca63d36e@syzkaller.appspotmail.com Cc: Nogah Frankel Cc: Jamal Hadi Salim Cc: Cong Wang Cc: Jiri Pirko Cc: netdev@vger.kernel.org Cc: "David S. Miller" Cc: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vlan: consolidate VLAN parsing code and limit max parsing depth

2020-12-11T12:39:03+00:00

[ Upstream commit 469aceddfa3ed16e17ee30533fae45e90f62efd8 ] Toshiaki pointed out that we now have two very similar functions to extract the L3 protocol number in the presence of VLAN tags. And Daniel pointed out that the unbounded parsing loop makes it possible for maliciously crafted packets to loop through potentially hundreds of tags. Fix both of these issues by consolidating the two parsing functions and limiting the VLAN tag parsing to a max depth of 8 tags. As part of this, switch over __vlan_get_protocol() to use skb_header_pointer() instead of pskb_may_pull(), to avoid the possible side effects of the latter and keep the skb pointer 'const' through all the parsing functions. v2: - Use limit of 8 tags instead of 32 (matching XMIT_RECURSION_LIMIT) Reported-by: Toshiaki Makita Reported-by: Daniel Borkmann Fixes: d7bf2ebebc2b ("sched: consistently handle layer3 header accesses in the presence of VLANs") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

bonding: wait for sysfs kobject destruction before freeing struct slave

2020-12-08T09:17:33+00:00

[ Upstream commit b9ad3e9f5a7a760ab068e33e1f18d240ba32ce92 ] syzkaller found that with CONFIG_DEBUG_KOBJECT_RELEASE=y, releasing a struct slave device could result in the following splat: kobject: 'bonding_slave' (00000000cecdd4fe): kobject_release, parent 0000000074ceb2b2 (delayed 1000) bond0 (unregistering): (slave bond_slave_1): Releasing backup interface ------------[ cut here ]------------ ODEBUG: free active (active state 0) object type: timer_list hint: workqueue_select_cpu_near kernel/workqueue.c:1549 [inline] ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x98 kernel/workqueue.c:1600 WARNING: CPU: 1 PID: 842 at lib/debugobjects.c:485 debug_print_object+0x180/0x240 lib/debugobjects.c:485 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 842 Comm: kworker/u4:4 Tainted: G S 5.9.0-rc8+ #96 Hardware name: linux,dummy-virt (DT) Workqueue: netns cleanup_net Call trace: dump_backtrace+0x0/0x4d8 include/linux/bitmap.h:239 show_stack+0x34/0x48 arch/arm64/kernel/traps.c:142 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x174/0x1f8 lib/dump_stack.c:118 panic+0x360/0x7a0 kernel/panic.c:231 __warn+0x244/0x2ec kernel/panic.c:600 report_bug+0x240/0x398 lib/bug.c:198 bug_handler+0x50/0xc0 arch/arm64/kernel/traps.c:974 call_break_hook+0x160/0x1d8 arch/arm64/kernel/debug-monitors.c:322 brk_handler+0x30/0xc0 arch/arm64/kernel/debug-monitors.c:329 do_debug_exception+0x184/0x340 arch/arm64/mm/fault.c:864 el1_dbg+0x48/0xb0 arch/arm64/kernel/entry-common.c:65 el1_sync_handler+0x170/0x1c8 arch/arm64/kernel/entry-common.c:93 el1_sync+0x80/0x100 arch/arm64/kernel/entry.S:594 debug_print_object+0x180/0x240 lib/debugobjects.c:485 __debug_check_no_obj_freed lib/debugobjects.c:967 [inline] debug_check_no_obj_freed+0x200/0x430 lib/debugobjects.c:998 slab_free_hook mm/slub.c:1536 [inline] slab_free_freelist_hook+0x190/0x210 mm/slub.c:1577 slab_free mm/slub.c:3138 [inline] kfree+0x13c/0x460 mm/slub.c:4119 bond_free_slave+0x8c/0xf8 drivers/net/bonding/bond_main.c:1492 __bond_release_one+0xe0c/0xec8 drivers/net/bonding/bond_main.c:2190 bond_slave_netdev_event drivers/net/bonding/bond_main.c:3309 [inline] bond_netdev_event+0x8f0/0xa70 drivers/net/bonding/bond_main.c:3420 notifier_call_chain+0xf0/0x200 kernel/notifier.c:83 __raw_notifier_call_chain kernel/notifier.c:361 [inline] raw_notifier_call_chain+0x44/0x58 kernel/notifier.c:368 call_netdevice_notifiers_info+0xbc/0x150 net/core/dev.c:2033 call_netdevice_notifiers_extack net/core/dev.c:2045 [inline] call_netdevice_notifiers net/core/dev.c:2059 [inline] rollback_registered_many+0x6a4/0xec0 net/core/dev.c:9347 unregister_netdevice_many.part.0+0x2c/0x1c0 net/core/dev.c:10509 unregister_netdevice_many net/core/dev.c:10508 [inline] default_device_exit_batch+0x294/0x338 net/core/dev.c:10992 ops_exit_list.isra.0+0xec/0x150 net/core/net_namespace.c:189 cleanup_net+0x44c/0x888 net/core/net_namespace.c:603 process_one_work+0x96c/0x18c0 kernel/workqueue.c:2269 worker_thread+0x3f0/0xc30 kernel/workqueue.c:2415 kthread+0x390/0x498 kernel/kthread.c:292 ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:925 This is a potential use-after-free if the sysfs nodes are being accessed whilst removing the struct slave, so wait for the object destruction to complete before freeing the struct slave itself. Fixes: 07699f9a7c8d ("bonding: add sysfs /slave dir for bond slave devices.") Fixes: a068aab42258 ("bonding: Fix reference count leak in bond_sysfs_slave_add.") Cc: Qiushi Wu Cc: Jay Vosburgh Cc: Veaceslav Falico Cc: Andy Gospodarek Signed-off-by: Jamie Iles Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20201120142827.879226-1-jamie@nuviainc.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/ipv4: always honour route mtu during forwarding

2020-10-29T08:06:58+00:00

[ Upstream commit 02a1b175b0e92d9e0fa5df3957ade8d733ceb6a0 ] Documentation/networking/ip-sysctl.txt:46 says: ip_forward_use_pmtu - BOOLEAN By default we don't trust protocol path MTUs while forwarding because they could be easily forged and can lead to unwanted fragmentation by the router. You only need to enable this if you have user-space software which tries to discover path mtus by itself and depends on the kernel honoring this information. This is normally not the case. Default: 0 (disabled) Possible values: 0 - disabled 1 - enabled Which makes it pretty clear that setting it to 1 is a potential security/safety/DoS issue, and yet it is entirely reasonable to want forwarded traffic to honour explicitly administrator configured route mtus (instead of defaulting to device mtu). Indeed, I can't think of a single reason why you wouldn't want to. Since you configured a route mtu you probably know better... It is pretty common to have a higher device mtu to allow receiving large (jumbo) frames, while having some routes via that interface (potentially including the default route to the internet) specify a lower mtu. Note that ipv6 forwarding uses device mtu unless the route is locked (in which case it will use the route mtu). This approach is not usable for IPv4 where an 'mtu lock' on a route also has the side effect of disabling TCP path mtu discovery via disabling the IPv4 DF (don't frag) bit on all outgoing frames. I'm not aware of a way to lock a route from an IPv6 RA, so that also potentially seems wrong. Signed-off-by: Maciej Żenczykowski Cc: Eric Dumazet Cc: Willem de Bruijn Cc: Lorenzo Colitti Cc: Sunmeet Gill (Sunny) Cc: Vinay Paradkar Cc: Tyler Wear Cc: David Ahern Reviewed-by: Eric Dumazet Signed-off-by: Greg Kroah-Hartman

Bluetooth: Disconnect if E0 is used for Level 4

2020-10-17T08:29:54+00:00

commit 8746f135bb01872ff412d408ea1aa9ebd328c1f5 upstream. E0 is not allowed with Level 4: BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C page 1319: '128-bit equivalent strength for link and encryption keys required using FIPS approved algorithms (E0 not allowed, SAFER+ not allowed, and P-192 not allowed; encryption key not shortened' SC enabled: > HCI Event: Read Remote Extended Features (0x23) plen 13 Status: Success (0x00) Handle: 256 Page: 1/2 Features: 0x0b 0x00 0x00 0x00 0x00 0x00 0x00 0x00 Secure Simple Pairing (Host Support) LE Supported (Host) Secure Connections (Host Support) > HCI Event: Encryption Change (0x08) plen 4 Status: Success (0x00) Handle: 256 Encryption: Enabled with AES-CCM (0x02) SC disabled: > HCI Event: Read Remote Extended Features (0x23) plen 13 Status: Success (0x00) Handle: 256 Page: 1/2 Features: 0x03 0x00 0x00 0x00 0x00 0x00 0x00 0x00 Secure Simple Pairing (Host Support) LE Supported (Host) > HCI Event: Encryption Change (0x08) plen 4 Status: Success (0x00) Handle: 256 Encryption: Enabled with E0 (0x01) [May 8 20:23] Bluetooth: hci0: Invalid security: expect AES but E0 was used < HCI Command: Disconnect (0x01|0x0006) plen 3 Handle: 256 Reason: Authentication Failure (0x05) Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann Cc: Hans-Christian Noren Egtvedt Signed-off-by: Greg Kroah-Hartman

Bluetooth: Fix update of connection state in `hci_encrypt_cfm`

2020-10-17T08:29:54+00:00

commit 339ddaa626995bc6218972ca241471f3717cc5f4 upstream. Starting with the upgrade to v5.8-rc3, I've noticed I wasn't able to connect to my Bluetooth headset properly anymore. While connecting to the device would eventually succeed, bluetoothd seemed to be confused about the current connection state where the state was flapping hence and forth. Bisecting this issue led to commit 3ca44c16b0dc (Bluetooth: Consolidate encryption handling in hci_encrypt_cfm, 2020-05-19), which refactored `hci_encrypt_cfm` to also handle updating the connection state. The commit in question changed the code to call `hci_connect_cfm` inside `hci_encrypt_cfm` and to change the connection state. But with the conversion, we now only update the connection state if a status was set already. In fact, the reverse should be true: the status should be updated if no status is yet set. So let's fix the isuse by reversing the condition. Fixes: 3ca44c16b0dc ("Bluetooth: Consolidate encryption handling in hci_encrypt_cfm") Signed-off-by: Patrick Steinhardt Acked-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann Signed-off-by: Greg Kroah-Hartman

Bluetooth: Consolidate encryption handling in hci_encrypt_cfm

2020-10-17T08:29:53+00:00

commit 3ca44c16b0dcc764b641ee4ac226909f5c421aa3 upstream. This makes hci_encrypt_cfm calls hci_connect_cfm in case the connection state is BT_CONFIG so callers don't have to check the state. Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann Cc: Hans-Christian Noren Egtvedt Signed-off-by: Greg Kroah-Hartman