support for overlayfs #447

bklier · 2013-11-25T17:08:49Z

Would it be possible to integrate overlayfs into the rpi kernel? That would be great for building rasperry systems which will be better protected from power failures (so they will not crash the filesystem due to unclean shutdowns...)

Re
Benjamin Klier

asb · 2013-11-25T17:20:11Z

Unless I'm very much mistaken overlayfs hasn't made it upstream right? We generally don't like to accept non-upstreamed patchsets due to the maintenance burden. Plus overlayfs is far from the last word in this area (people will ask, why not aufs, or...). Have you looked at using devicemapper thin provisioning as Docker is moving to (it's moving from aufs as distros like RHEL don't want to carry out of tree patchsets like that either).

bklier · 2013-11-27T09:55:12Z

That sounds like a very promising solution - maybe you can provide me with some in depth information about this topic?

popcornmix · 2014-12-29T20:14:46Z

You can use the BRANCH=next firmware or build from rpi-3.18.y kernel tree for this.

rmnet registers IFLA_LINK interface as a lower interface. But, IFLA_LINK could be NULL. In the current code, rmnet doesn't check IFLA_LINK. So, panic would occur. Test commands: modprobe rmnet ip link add rmnet0 type rmnet mux_id 1 Splat looks like: [ 36.826109][ T1115] general protection fault, probably for non-canonical address 0xdffffc0000000000I [ 36.838817][ T1115] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 36.839908][ T1115] CPU: 1 PID: 1115 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 36.840569][ T1115] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 36.841408][ T1115] RIP: 0010:rmnet_newlink+0x54/0x510 [rmnet] [ 36.841986][ T1115] Code: 83 ec 18 48 c1 e9 03 80 3c 01 00 0f 85 d4 03 00 00 48 8b 6a 28 48 b8 00 00 00 00 00 c [ 36.843923][ T1115] RSP: 0018:ffff8880b7e0f1c0 EFLAGS: 00010247 [ 36.844756][ T1115] RAX: dffffc0000000000 RBX: ffff8880d14cca00 RCX: 1ffff11016fc1e99 [ 36.845859][ T1115] RDX: 0000000000000000 RSI: ffff8880c3d04000 RDI: 0000000000000004 [ 36.846961][ T1115] RBP: 0000000000000000 R08: ffff8880b7e0f8b0 R09: ffff8880b6ac2d90 [ 36.848020][ T1115] R10: ffffffffc0589a40 R11: ffffed1016d585b7 R12: ffffffff88ceaf80 [ 36.848788][ T1115] R13: ffff8880c3d04000 R14: ffff8880b7e0f8b0 R15: ffff8880c3d04000 [ 36.849546][ T1115] FS: 00007f50ab3360c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 36.851784][ T1115] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.852422][ T1115] CR2: 000055871afe5ab0 CR3: 00000000ae246001 CR4: 00000000000606e0 [ 36.853181][ T1115] Call Trace: [ 36.853514][ T1115] __rtnl_newlink+0xbdb/0x1270 [ 36.853967][ T1115] ? lock_downgrade+0x6e0/0x6e0 [ 36.854420][ T1115] ? rtnl_link_unregister+0x220/0x220 [ 36.854936][ T1115] ? lock_acquire+0x164/0x3b0 [ 36.855376][ T1115] ? is_bpf_image_address+0xff/0x1d0 [ 36.855884][ T1115] ? rtnl_newlink+0x4c/0x90 [ 36.856304][ T1115] ? kernel_text_address+0x111/0x140 [ 36.856857][ T1115] ? __kernel_text_address+0xe/0x30 [ 36.857440][ T1115] ? unwind_get_return_address+0x5f/0xa0 [ 36.858063][ T1115] ? create_prof_cpu_mask+0x20/0x20 [ 36.858644][ T1115] ? arch_stack_walk+0x83/0xb0 [ 36.859171][ T1115] ? stack_trace_save+0x82/0xb0 [ 36.859710][ T1115] ? stack_trace_consume_entry+0x160/0x160 [ 36.860357][ T1115] ? deactivate_slab.isra.78+0x2c5/0x800 [ 36.860928][ T1115] ? kasan_unpoison_shadow+0x30/0x40 [ 36.861520][ T1115] ? kmem_cache_alloc_trace+0x135/0x350 [ 36.862125][ T1115] ? rtnl_newlink+0x4c/0x90 [ 36.864073][ T1115] rtnl_newlink+0x65/0x90 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

In the rmnet_changelink(), it uses IFLA_LINK without checking NULL pointer. tb[IFLA_LINK] could be NULL pointer. So, NULL-ptr-deref could occur. rmnet already has a lower interface (real_dev). So, after this patch, rmnet_changelink() does not use IFLA_LINK anymore. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link set rmnet0 type rmnet mux_id 2 Splat looks like: [ 90.578726][ T1131] general protection fault, probably for non-canonical address 0xdffffc0000000000I [ 90.581121][ T1131] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 90.582380][ T1131] CPU: 2 PID: 1131 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 90.584285][ T1131] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 90.587506][ T1131] RIP: 0010:rmnet_changelink+0x5a/0x8a0 [rmnet] [ 90.588546][ T1131] Code: 83 ec 20 48 c1 ea 03 80 3c 02 00 0f 85 6f 07 00 00 48 8b 5e 28 48 b8 00 00 00 00 00 0 [ 90.591447][ T1131] RSP: 0018:ffff8880ce78f1b8 EFLAGS: 00010247 [ 90.592329][ T1131] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8880ce78f8b0 [ 90.593253][ T1131] RDX: 0000000000000000 RSI: ffff8880ce78f4a0 RDI: 0000000000000004 [ 90.594058][ T1131] RBP: ffff8880cf543e00 R08: 0000000000000002 R09: 0000000000000002 [ 90.594859][ T1131] R10: ffffffffc0586a40 R11: 0000000000000000 R12: ffff8880ca47c000 [ 90.595690][ T1131] R13: ffff8880ca47c000 R14: ffff8880cf545000 R15: 0000000000000000 [ 90.596553][ T1131] FS: 00007f21f6c7e0c0(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000 [ 90.597504][ T1131] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 90.599418][ T1131] CR2: 0000556e413db458 CR3: 00000000c917a002 CR4: 00000000000606e0 [ 90.600289][ T1131] Call Trace: [ 90.600631][ T1131] __rtnl_newlink+0x922/0x1270 [ 90.601194][ T1131] ? lock_downgrade+0x6e0/0x6e0 [ 90.601724][ T1131] ? rtnl_link_unregister+0x220/0x220 [ 90.602309][ T1131] ? lock_acquire+0x164/0x3b0 [ 90.602784][ T1131] ? is_bpf_image_address+0xff/0x1d0 [ 90.603331][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.603810][ T1131] ? kernel_text_address+0x111/0x140 [ 90.604419][ T1131] ? __kernel_text_address+0xe/0x30 [ 90.604981][ T1131] ? unwind_get_return_address+0x5f/0xa0 [ 90.605616][ T1131] ? create_prof_cpu_mask+0x20/0x20 [ 90.606304][ T1131] ? arch_stack_walk+0x83/0xb0 [ 90.606985][ T1131] ? stack_trace_save+0x82/0xb0 [ 90.607656][ T1131] ? stack_trace_consume_entry+0x160/0x160 [ 90.608503][ T1131] ? deactivate_slab.isra.78+0x2c5/0x800 [ 90.609336][ T1131] ? kasan_unpoison_shadow+0x30/0x40 [ 90.610096][ T1131] ? kmem_cache_alloc_trace+0x135/0x350 [ 90.610889][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.611512][ T1131] rtnl_newlink+0x65/0x90 [ ... ] Fixes: 23790ef ("net: qualcomm: rmnet: Allow to configure flags for existing devices") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

rmnet_get_port() internally calls rcu_dereference_rtnl(), which checks RTNL. But rmnet_get_port() could be called by packet path. The packet path is not protected by RTNL. So, the suspicious RCU usage problem occurs. Test commands: modprobe rmnet ip netns add nst ip link add veth0 type veth peer name veth1 ip link set veth1 netns nst ip link add rmnet0 link veth0 type rmnet mux_id 1 ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1 ip netns exec nst ip link set veth1 up ip netns exec nst ip link set rmnet1 up ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1 ip link set veth0 up ip link set rmnet0 up ip a a 192.168.100.1/24 dev rmnet0 ping 192.168.100.2 Splat looks like: [ 146.630958][ T1174] WARNING: suspicious RCU usage [ 146.631735][ T1174] 5.6.0-rc1+ #447 Not tainted [ 146.632387][ T1174] ----------------------------- [ 146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() ! [ 146.634742][ T1174] [ 146.634742][ T1174] other info that might help us debug this: [ 146.634742][ T1174] [ 146.645992][ T1174] [ 146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1 [ 146.646937][ T1174] 5 locks held by ping/1174: [ 146.647609][ T1174] #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980 [ 146.662463][ T1174] #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150 [ 146.671696][ T1174] #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940 [ 146.673064][ T1174] #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150 [ 146.690358][ T1174] #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020 [ 146.699875][ T1174] [ 146.699875][ T1174] stack backtrace: [ 146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ #447 [ 146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 146.706565][ T1174] Call Trace: [ 146.707102][ T1174] dump_stack+0x96/0xdb [ 146.708007][ T1174] rmnet_get_port.part.9+0x76/0x80 [rmnet] [ 146.709233][ T1174] rmnet_egress_handler+0x107/0x420 [rmnet] [ 146.710492][ T1174] ? sch_direct_xmit+0x1e2/0x1020 [ 146.716193][ T1174] rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet] [ 146.717012][ T1174] dev_hard_start_xmit+0x160/0x740 [ 146.717854][ T1174] sch_direct_xmit+0x265/0x1020 [ 146.718577][ T1174] ? register_lock_class+0x14d0/0x14d0 [ 146.719429][ T1174] ? dev_watchdog+0xac0/0xac0 [ 146.723738][ T1174] ? __dev_queue_xmit+0x15fd/0x2940 [ 146.724469][ T1174] ? lock_acquire+0x164/0x3b0 [ 146.725172][ T1174] __dev_queue_xmit+0x20c7/0x2940 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

The notifier_call() of the slave interface removes rmnet interface with unregister_netdevice_queue(). But, before calling unregister_netdevice_queue(), it acquires rcu readlock. In the RCU critical section, sleeping isn't be allowed. But, unregister_netdevice_queue() internally calls synchronize_net(), which would sleep. So, suspicious RCU usage warning occurs. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add dummy1 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link set dummy1 master rmnet0 ip link del dummy0 Splat looks like: [ 79.639245][ T1195] ============================= [ 79.640134][ T1195] WARNING: suspicious RCU usage [ 79.640852][ T1195] 5.6.0-rc1+ #447 Not tainted [ 79.641657][ T1195] ----------------------------- [ 79.642472][ T1195] ./include/linux/rcupdate.h:273 Illegal context switch in RCU read-side critical section! [ 79.644043][ T1195] [ 79.644043][ T1195] other info that might help us debug this: [ 79.644043][ T1195] [ 79.645682][ T1195] [ 79.645682][ T1195] rcu_scheduler_active = 2, debug_locks = 1 [ 79.646980][ T1195] 2 locks held by ip/1195: [ 79.647629][ T1195] #0: ffffffffa3cf64f0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x457/0x890 [ 79.649312][ T1195] #1: ffffffffa39256c0 (rcu_read_lock){....}, at: rmnet_config_notify_cb+0xf0/0x590 [rmnet] [ 79.651717][ T1195] [ 79.651717][ T1195] stack backtrace: [ 79.652650][ T1195] CPU: 3 PID: 1195 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 79.653702][ T1195] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 79.655037][ T1195] Call Trace: [ 79.655560][ T1195] dump_stack+0x96/0xdb [ 79.656252][ T1195] ___might_sleep+0x345/0x440 [ 79.656994][ T1195] synchronize_net+0x18/0x30 [ 79.661132][ T1195] netdev_rx_handler_unregister+0x40/0xb0 [ 79.666266][ T1195] rmnet_unregister_real_device+0x42/0xb0 [rmnet] [ 79.667211][ T1195] rmnet_config_notify_cb+0x1f7/0x590 [rmnet] [ 79.668121][ T1195] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 79.669166][ T1195] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 79.670286][ T1195] ? __module_text_address+0x13/0x140 [ 79.671139][ T1195] notifier_call_chain+0x90/0x160 [ 79.671973][ T1195] rollback_registered_many+0x660/0xcf0 [ 79.672893][ T1195] ? netif_set_real_num_tx_queues+0x780/0x780 [ 79.675091][ T1195] ? __lock_acquire+0xdfe/0x3de0 [ 79.675825][ T1195] ? memset+0x1f/0x40 [ 79.676367][ T1195] ? __nla_validate_parse+0x98/0x1ab0 [ 79.677290][ T1195] unregister_netdevice_many.part.133+0x13/0x1b0 [ 79.678163][ T1195] rtnl_delete_link+0xbc/0x100 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

netdev_upper_dev_link() is useful to manage lower/upper interfaces. And this function internally validates looping, maximum depth. All or most virtual interfaces that could have a real interface (e.g. macsec, macvlan, ipvlan etc.) use lower/upper infrastructure. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet1 link dummy0 type rmnet mux_id 1 for i in {2..100} do let A=$i-1 ip link add rmnet$i link rmnet$A type rmnet mux_id $i done ip link del dummy0 The purpose of the test commands is to make stack overflow. Splat looks like: [ 52.411438][ T1395] BUG: KASAN: slab-out-of-bounds in find_busiest_group+0x27e/0x2c00 [ 52.413218][ T1395] Write of size 64 at addr ffff8880c774bde0 by task ip/1395 [ 52.414841][ T1395] [ 52.430720][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.496511][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.513597][ T1395] Call Trace: [ 52.546516][ T1395] [ 52.558773][ T1395] Allocated by task 3171537984: [ 52.588290][ T1395] BUG: unable to handle page fault for address: ffffffffb999e260 [ 52.589311][ T1395] #PF: supervisor read access in kernel mode [ 52.590529][ T1395] #PF: error_code(0x0000) - not-present page [ 52.591374][ T1395] PGD d6818067 P4D d6818067 PUD d6819063 PMD 0 [ 52.592288][ T1395] Thread overran stack, or stack corrupted [ 52.604980][ T1395] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 52.605856][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.611764][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.621520][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.622296][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 52.627887][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 52.628735][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 52.631773][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 52.649584][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 52.674857][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 52.678257][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 52.694541][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 52.764039][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 52.815008][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 52.862312][ T1395] Call Trace: [ 52.887133][ T1395] Modules linked in: dummy rmnet veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_dex [ 52.936749][ T1395] CR2: ffffffffb999e260 [ 52.965695][ T1395] ---[ end trace 7e32ca99482dbb31 ]--- [ 52.966556][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.971083][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 53.003650][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 53.043183][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 53.076480][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 53.093858][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 53.112795][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 53.139837][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 53.141500][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 53.143343][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 53.152007][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 53.156459][ T1395] Kernel panic - not syncing: Fatal exception [ 54.213570][ T1395] Shutting down cpus with NMI [ 54.354112][ T1395] Kernel Offset: 0x33000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0x) [ 54.355687][ T1395] Rebooting in 5 seconds.. Fixes: b37f78f ("net: qualcomm: rmnet: Fix crash on real dev unregistration") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

In order to attach a bridge interface to the rmnet interface, "master" operation is used. (e.g. ip link set dummy1 master rmnet0) But, in the rmnet_add_bridge(), which is a callback of ->ndo_add_slave() doesn't register lower interface. So, ->ndo_del_slave() doesn't work. There are other problems too. 1. It couldn't detect circular upper/lower interface relationship. 2. It couldn't prevent stack overflow because of too deep depth of upper/lower interface 3. It doesn't check the number of lower interfaces. 4. Panics because of several reasons. The root problem of these issues is actually the same. So, in this patch, these all problems will be fixed. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link add dummy1 master rmnet0 type dummy ip link add dummy2 master rmnet0 type dummy ip link del rmnet0 ip link del dummy2 ip link del dummy1 Splat looks like: [ 41.867595][ T1164] general protection fault, probably for non-canonical address 0xdffffc0000000101I [ 41.869993][ T1164] KASAN: null-ptr-deref in range [0x0000000000000808-0x000000000000080f] [ 41.872950][ T1164] CPU: 0 PID: 1164 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 41.873915][ T1164] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 41.875161][ T1164] RIP: 0010:rmnet_unregister_bridge.isra.6+0x71/0xf0 [rmnet] [ 41.876178][ T1164] Code: 48 89 ef 48 89 c6 5b 5d e9 fc fe ff ff e8 f7 f3 ff ff 48 8d b8 08 08 00 00 48 ba 00 7 [ 41.878925][ T1164] RSP: 0018:ffff8880c4d0f188 EFLAGS: 00010202 [ 41.879774][ T1164] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000101 [ 41.887689][ T1164] RDX: dffffc0000000000 RSI: ffffffffb8cf64f0 RDI: 0000000000000808 [ 41.888727][ T1164] RBP: ffff8880c40e4000 R08: ffffed101b3c0e3c R09: 0000000000000001 [ 41.889749][ T1164] R10: 0000000000000001 R11: ffffed101b3c0e3b R12: 1ffff110189a1e3c [ 41.890783][ T1164] R13: ffff8880c4d0f200 R14: ffffffffb8d56160 R15: ffff8880ccc2c000 [ 41.891794][ T1164] FS: 00007f4300edc0c0(0000) GS:ffff8880d9c00000(0000) knlGS:0000000000000000 [ 41.892953][ T1164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.893800][ T1164] CR2: 00007f43003bc8c0 CR3: 00000000ca53e001 CR4: 00000000000606f0 [ 41.894824][ T1164] Call Trace: [ 41.895274][ T1164] ? rcu_is_watching+0x2c/0x80 [ 41.895895][ T1164] rmnet_config_notify_cb+0x1f7/0x590 [rmnet] [ 41.896687][ T1164] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 41.897611][ T1164] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 41.898508][ T1164] ? __module_text_address+0x13/0x140 [ 41.899162][ T1164] notifier_call_chain+0x90/0x160 [ 41.899814][ T1164] rollback_registered_many+0x660/0xcf0 [ 41.900544][ T1164] ? netif_set_real_num_tx_queues+0x780/0x780 [ 41.901316][ T1164] ? __lock_acquire+0xdfe/0x3de0 [ 41.901958][ T1164] ? memset+0x1f/0x40 [ 41.902468][ T1164] ? __nla_validate_parse+0x98/0x1ab0 [ 41.903166][ T1164] unregister_netdevice_many.part.133+0x13/0x1b0 [ 41.903988][ T1164] rtnl_delete_link+0xbc/0x100 [ ... ] Fixes: 60d58f9 ("net: qualcomm: rmnet: Implement bridge mode") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>

[ Upstream commit 93b5cbf ] rmnet registers IFLA_LINK interface as a lower interface. But, IFLA_LINK could be NULL. In the current code, rmnet doesn't check IFLA_LINK. So, panic would occur. Test commands: modprobe rmnet ip link add rmnet0 type rmnet mux_id 1 Splat looks like: [ 36.826109][ T1115] general protection fault, probably for non-canonical address 0xdffffc0000000000I [ 36.838817][ T1115] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 36.839908][ T1115] CPU: 1 PID: 1115 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 36.840569][ T1115] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 36.841408][ T1115] RIP: 0010:rmnet_newlink+0x54/0x510 [rmnet] [ 36.841986][ T1115] Code: 83 ec 18 48 c1 e9 03 80 3c 01 00 0f 85 d4 03 00 00 48 8b 6a 28 48 b8 00 00 00 00 00 c [ 36.843923][ T1115] RSP: 0018:ffff8880b7e0f1c0 EFLAGS: 00010247 [ 36.844756][ T1115] RAX: dffffc0000000000 RBX: ffff8880d14cca00 RCX: 1ffff11016fc1e99 [ 36.845859][ T1115] RDX: 0000000000000000 RSI: ffff8880c3d04000 RDI: 0000000000000004 [ 36.846961][ T1115] RBP: 0000000000000000 R08: ffff8880b7e0f8b0 R09: ffff8880b6ac2d90 [ 36.848020][ T1115] R10: ffffffffc0589a40 R11: ffffed1016d585b7 R12: ffffffff88ceaf80 [ 36.848788][ T1115] R13: ffff8880c3d04000 R14: ffff8880b7e0f8b0 R15: ffff8880c3d04000 [ 36.849546][ T1115] FS: 00007f50ab3360c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 36.851784][ T1115] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.852422][ T1115] CR2: 000055871afe5ab0 CR3: 00000000ae246001 CR4: 00000000000606e0 [ 36.853181][ T1115] Call Trace: [ 36.853514][ T1115] __rtnl_newlink+0xbdb/0x1270 [ 36.853967][ T1115] ? lock_downgrade+0x6e0/0x6e0 [ 36.854420][ T1115] ? rtnl_link_unregister+0x220/0x220 [ 36.854936][ T1115] ? lock_acquire+0x164/0x3b0 [ 36.855376][ T1115] ? is_bpf_image_address+0xff/0x1d0 [ 36.855884][ T1115] ? rtnl_newlink+0x4c/0x90 [ 36.856304][ T1115] ? kernel_text_address+0x111/0x140 [ 36.856857][ T1115] ? __kernel_text_address+0xe/0x30 [ 36.857440][ T1115] ? unwind_get_return_address+0x5f/0xa0 [ 36.858063][ T1115] ? create_prof_cpu_mask+0x20/0x20 [ 36.858644][ T1115] ? arch_stack_walk+0x83/0xb0 [ 36.859171][ T1115] ? stack_trace_save+0x82/0xb0 [ 36.859710][ T1115] ? stack_trace_consume_entry+0x160/0x160 [ 36.860357][ T1115] ? deactivate_slab.isra.78+0x2c5/0x800 [ 36.860928][ T1115] ? kasan_unpoison_shadow+0x30/0x40 [ 36.861520][ T1115] ? kmem_cache_alloc_trace+0x135/0x350 [ 36.862125][ T1115] ? rtnl_newlink+0x4c/0x90 [ 36.864073][ T1115] rtnl_newlink+0x65/0x90 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 1eb1f43 ] In the rmnet_changelink(), it uses IFLA_LINK without checking NULL pointer. tb[IFLA_LINK] could be NULL pointer. So, NULL-ptr-deref could occur. rmnet already has a lower interface (real_dev). So, after this patch, rmnet_changelink() does not use IFLA_LINK anymore. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link set rmnet0 type rmnet mux_id 2 Splat looks like: [ 90.578726][ T1131] general protection fault, probably for non-canonical address 0xdffffc0000000000I [ 90.581121][ T1131] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 90.582380][ T1131] CPU: 2 PID: 1131 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 90.584285][ T1131] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 90.587506][ T1131] RIP: 0010:rmnet_changelink+0x5a/0x8a0 [rmnet] [ 90.588546][ T1131] Code: 83 ec 20 48 c1 ea 03 80 3c 02 00 0f 85 6f 07 00 00 48 8b 5e 28 48 b8 00 00 00 00 00 0 [ 90.591447][ T1131] RSP: 0018:ffff8880ce78f1b8 EFLAGS: 00010247 [ 90.592329][ T1131] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8880ce78f8b0 [ 90.593253][ T1131] RDX: 0000000000000000 RSI: ffff8880ce78f4a0 RDI: 0000000000000004 [ 90.594058][ T1131] RBP: ffff8880cf543e00 R08: 0000000000000002 R09: 0000000000000002 [ 90.594859][ T1131] R10: ffffffffc0586a40 R11: 0000000000000000 R12: ffff8880ca47c000 [ 90.595690][ T1131] R13: ffff8880ca47c000 R14: ffff8880cf545000 R15: 0000000000000000 [ 90.596553][ T1131] FS: 00007f21f6c7e0c0(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000 [ 90.597504][ T1131] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 90.599418][ T1131] CR2: 0000556e413db458 CR3: 00000000c917a002 CR4: 00000000000606e0 [ 90.600289][ T1131] Call Trace: [ 90.600631][ T1131] __rtnl_newlink+0x922/0x1270 [ 90.601194][ T1131] ? lock_downgrade+0x6e0/0x6e0 [ 90.601724][ T1131] ? rtnl_link_unregister+0x220/0x220 [ 90.602309][ T1131] ? lock_acquire+0x164/0x3b0 [ 90.602784][ T1131] ? is_bpf_image_address+0xff/0x1d0 [ 90.603331][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.603810][ T1131] ? kernel_text_address+0x111/0x140 [ 90.604419][ T1131] ? __kernel_text_address+0xe/0x30 [ 90.604981][ T1131] ? unwind_get_return_address+0x5f/0xa0 [ 90.605616][ T1131] ? create_prof_cpu_mask+0x20/0x20 [ 90.606304][ T1131] ? arch_stack_walk+0x83/0xb0 [ 90.606985][ T1131] ? stack_trace_save+0x82/0xb0 [ 90.607656][ T1131] ? stack_trace_consume_entry+0x160/0x160 [ 90.608503][ T1131] ? deactivate_slab.isra.78+0x2c5/0x800 [ 90.609336][ T1131] ? kasan_unpoison_shadow+0x30/0x40 [ 90.610096][ T1131] ? kmem_cache_alloc_trace+0x135/0x350 [ 90.610889][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.611512][ T1131] rtnl_newlink+0x65/0x90 [ ... ] Fixes: 23790ef ("net: qualcomm: rmnet: Allow to configure flags for existing devices") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 102210f ] rmnet_get_port() internally calls rcu_dereference_rtnl(), which checks RTNL. But rmnet_get_port() could be called by packet path. The packet path is not protected by RTNL. So, the suspicious RCU usage problem occurs. Test commands: modprobe rmnet ip netns add nst ip link add veth0 type veth peer name veth1 ip link set veth1 netns nst ip link add rmnet0 link veth0 type rmnet mux_id 1 ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1 ip netns exec nst ip link set veth1 up ip netns exec nst ip link set rmnet1 up ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1 ip link set veth0 up ip link set rmnet0 up ip a a 192.168.100.1/24 dev rmnet0 ping 192.168.100.2 Splat looks like: [ 146.630958][ T1174] WARNING: suspicious RCU usage [ 146.631735][ T1174] 5.6.0-rc1+ #447 Not tainted [ 146.632387][ T1174] ----------------------------- [ 146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() ! [ 146.634742][ T1174] [ 146.634742][ T1174] other info that might help us debug this: [ 146.634742][ T1174] [ 146.645992][ T1174] [ 146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1 [ 146.646937][ T1174] 5 locks held by ping/1174: [ 146.647609][ T1174] #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980 [ 146.662463][ T1174] #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150 [ 146.671696][ T1174] #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940 [ 146.673064][ T1174] #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150 [ 146.690358][ T1174] #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020 [ 146.699875][ T1174] [ 146.699875][ T1174] stack backtrace: [ 146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ #447 [ 146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 146.706565][ T1174] Call Trace: [ 146.707102][ T1174] dump_stack+0x96/0xdb [ 146.708007][ T1174] rmnet_get_port.part.9+0x76/0x80 [rmnet] [ 146.709233][ T1174] rmnet_egress_handler+0x107/0x420 [rmnet] [ 146.710492][ T1174] ? sch_direct_xmit+0x1e2/0x1020 [ 146.716193][ T1174] rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet] [ 146.717012][ T1174] dev_hard_start_xmit+0x160/0x740 [ 146.717854][ T1174] sch_direct_xmit+0x265/0x1020 [ 146.718577][ T1174] ? register_lock_class+0x14d0/0x14d0 [ 146.719429][ T1174] ? dev_watchdog+0xac0/0xac0 [ 146.723738][ T1174] ? __dev_queue_xmit+0x15fd/0x2940 [ 146.724469][ T1174] ? lock_acquire+0x164/0x3b0 [ 146.725172][ T1174] __dev_queue_xmit+0x20c7/0x2940 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit c026d97 ] The notifier_call() of the slave interface removes rmnet interface with unregister_netdevice_queue(). But, before calling unregister_netdevice_queue(), it acquires rcu readlock. In the RCU critical section, sleeping isn't be allowed. But, unregister_netdevice_queue() internally calls synchronize_net(), which would sleep. So, suspicious RCU usage warning occurs. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add dummy1 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link set dummy1 master rmnet0 ip link del dummy0 Splat looks like: [ 79.639245][ T1195] ============================= [ 79.640134][ T1195] WARNING: suspicious RCU usage [ 79.640852][ T1195] 5.6.0-rc1+ #447 Not tainted [ 79.641657][ T1195] ----------------------------- [ 79.642472][ T1195] ./include/linux/rcupdate.h:273 Illegal context switch in RCU read-side critical section! [ 79.644043][ T1195] [ 79.644043][ T1195] other info that might help us debug this: [ 79.644043][ T1195] [ 79.645682][ T1195] [ 79.645682][ T1195] rcu_scheduler_active = 2, debug_locks = 1 [ 79.646980][ T1195] 2 locks held by ip/1195: [ 79.647629][ T1195] #0: ffffffffa3cf64f0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x457/0x890 [ 79.649312][ T1195] #1: ffffffffa39256c0 (rcu_read_lock){....}, at: rmnet_config_notify_cb+0xf0/0x590 [rmnet] [ 79.651717][ T1195] [ 79.651717][ T1195] stack backtrace: [ 79.652650][ T1195] CPU: 3 PID: 1195 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 79.653702][ T1195] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 79.655037][ T1195] Call Trace: [ 79.655560][ T1195] dump_stack+0x96/0xdb [ 79.656252][ T1195] ___might_sleep+0x345/0x440 [ 79.656994][ T1195] synchronize_net+0x18/0x30 [ 79.661132][ T1195] netdev_rx_handler_unregister+0x40/0xb0 [ 79.666266][ T1195] rmnet_unregister_real_device+0x42/0xb0 [rmnet] [ 79.667211][ T1195] rmnet_config_notify_cb+0x1f7/0x590 [rmnet] [ 79.668121][ T1195] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 79.669166][ T1195] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 79.670286][ T1195] ? __module_text_address+0x13/0x140 [ 79.671139][ T1195] notifier_call_chain+0x90/0x160 [ 79.671973][ T1195] rollback_registered_many+0x660/0xcf0 [ 79.672893][ T1195] ? netif_set_real_num_tx_queues+0x780/0x780 [ 79.675091][ T1195] ? __lock_acquire+0xdfe/0x3de0 [ 79.675825][ T1195] ? memset+0x1f/0x40 [ 79.676367][ T1195] ? __nla_validate_parse+0x98/0x1ab0 [ 79.677290][ T1195] unregister_netdevice_many.part.133+0x13/0x1b0 [ 79.678163][ T1195] rtnl_delete_link+0xbc/0x100 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 037f9cd ] netdev_upper_dev_link() is useful to manage lower/upper interfaces. And this function internally validates looping, maximum depth. All or most virtual interfaces that could have a real interface (e.g. macsec, macvlan, ipvlan etc.) use lower/upper infrastructure. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet1 link dummy0 type rmnet mux_id 1 for i in {2..100} do let A=$i-1 ip link add rmnet$i link rmnet$A type rmnet mux_id $i done ip link del dummy0 The purpose of the test commands is to make stack overflow. Splat looks like: [ 52.411438][ T1395] BUG: KASAN: slab-out-of-bounds in find_busiest_group+0x27e/0x2c00 [ 52.413218][ T1395] Write of size 64 at addr ffff8880c774bde0 by task ip/1395 [ 52.414841][ T1395] [ 52.430720][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.496511][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.513597][ T1395] Call Trace: [ 52.546516][ T1395] [ 52.558773][ T1395] Allocated by task 3171537984: [ 52.588290][ T1395] BUG: unable to handle page fault for address: ffffffffb999e260 [ 52.589311][ T1395] #PF: supervisor read access in kernel mode [ 52.590529][ T1395] #PF: error_code(0x0000) - not-present page [ 52.591374][ T1395] PGD d6818067 P4D d6818067 PUD d6819063 PMD 0 [ 52.592288][ T1395] Thread overran stack, or stack corrupted [ 52.604980][ T1395] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 52.605856][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.611764][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.621520][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.622296][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 52.627887][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 52.628735][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 52.631773][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 52.649584][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 52.674857][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 52.678257][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 52.694541][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 52.764039][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 52.815008][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 52.862312][ T1395] Call Trace: [ 52.887133][ T1395] Modules linked in: dummy rmnet veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_dex [ 52.936749][ T1395] CR2: ffffffffb999e260 [ 52.965695][ T1395] ---[ end trace 7e32ca99482dbb31 ]--- [ 52.966556][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.971083][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 53.003650][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 53.043183][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 53.076480][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 53.093858][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 53.112795][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 53.139837][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 53.141500][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 53.143343][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 53.152007][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 53.156459][ T1395] Kernel panic - not syncing: Fatal exception [ 54.213570][ T1395] Shutting down cpus with NMI [ 54.354112][ T1395] Kernel Offset: 0x33000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0x) [ 54.355687][ T1395] Rebooting in 5 seconds.. Fixes: b37f78f ("net: qualcomm: rmnet: Fix crash on real dev unregistration") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit d939b6d ] In order to attach a bridge interface to the rmnet interface, "master" operation is used. (e.g. ip link set dummy1 master rmnet0) But, in the rmnet_add_bridge(), which is a callback of ->ndo_add_slave() doesn't register lower interface. So, ->ndo_del_slave() doesn't work. There are other problems too. 1. It couldn't detect circular upper/lower interface relationship. 2. It couldn't prevent stack overflow because of too deep depth of upper/lower interface 3. It doesn't check the number of lower interfaces. 4. Panics because of several reasons. The root problem of these issues is actually the same. So, in this patch, these all problems will be fixed. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link add dummy1 master rmnet0 type dummy ip link add dummy2 master rmnet0 type dummy ip link del rmnet0 ip link del dummy2 ip link del dummy1 Splat looks like: [ 41.867595][ T1164] general protection fault, probably for non-canonical address 0xdffffc0000000101I [ 41.869993][ T1164] KASAN: null-ptr-deref in range [0x0000000000000808-0x000000000000080f] [ 41.872950][ T1164] CPU: 0 PID: 1164 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 41.873915][ T1164] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 41.875161][ T1164] RIP: 0010:rmnet_unregister_bridge.isra.6+0x71/0xf0 [rmnet] [ 41.876178][ T1164] Code: 48 89 ef 48 89 c6 5b 5d e9 fc fe ff ff e8 f7 f3 ff ff 48 8d b8 08 08 00 00 48 ba 00 7 [ 41.878925][ T1164] RSP: 0018:ffff8880c4d0f188 EFLAGS: 00010202 [ 41.879774][ T1164] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000101 [ 41.887689][ T1164] RDX: dffffc0000000000 RSI: ffffffffb8cf64f0 RDI: 0000000000000808 [ 41.888727][ T1164] RBP: ffff8880c40e4000 R08: ffffed101b3c0e3c R09: 0000000000000001 [ 41.889749][ T1164] R10: 0000000000000001 R11: ffffed101b3c0e3b R12: 1ffff110189a1e3c [ 41.890783][ T1164] R13: ffff8880c4d0f200 R14: ffffffffb8d56160 R15: ffff8880ccc2c000 [ 41.891794][ T1164] FS: 00007f4300edc0c0(0000) GS:ffff8880d9c00000(0000) knlGS:0000000000000000 [ 41.892953][ T1164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.893800][ T1164] CR2: 00007f43003bc8c0 CR3: 00000000ca53e001 CR4: 00000000000606f0 [ 41.894824][ T1164] Call Trace: [ 41.895274][ T1164] ? rcu_is_watching+0x2c/0x80 [ 41.895895][ T1164] rmnet_config_notify_cb+0x1f7/0x590 [rmnet] [ 41.896687][ T1164] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 41.897611][ T1164] ? rmnet_unregister_bridge.isra.6+0xf0/0xf0 [rmnet] [ 41.898508][ T1164] ? __module_text_address+0x13/0x140 [ 41.899162][ T1164] notifier_call_chain+0x90/0x160 [ 41.899814][ T1164] rollback_registered_many+0x660/0xcf0 [ 41.900544][ T1164] ? netif_set_real_num_tx_queues+0x780/0x780 [ 41.901316][ T1164] ? __lock_acquire+0xdfe/0x3de0 [ 41.901958][ T1164] ? memset+0x1f/0x40 [ 41.902468][ T1164] ? __nla_validate_parse+0x98/0x1ab0 [ 41.903166][ T1164] unregister_netdevice_many.part.133+0x13/0x1b0 [ 41.903988][ T1164] rtnl_delete_link+0xbc/0x100 [ ... ] Fixes: 60d58f9 ("net: qualcomm: rmnet: Implement bridge mode") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>