kernel/linux.git, branch v5.6.16

Linux 5.6.16

2020-06-03T06:23:38+00:00

netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build

2020-06-03T06:23:38+00:00

commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream. >> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers] extern const char *const pptp_msg_name(u_int16_t msg); ^~~~~~ Reported-by: kbuild test robot Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: conntrack: Pass value of ctinfo to __nf_conntrack_update

2020-06-03T06:23:37+00:00

commit 46c1e0621a72e0469ec4edfdb6ed4d387ec34f8a upstream. Clang warns: net/netfilter/nf_conntrack_core.c:2068:21: warning: variable 'ctinfo' is uninitialized when used here [-Wuninitialized] nf_ct_set(skb, ct, ctinfo); ^~~~~~ net/netfilter/nf_conntrack_core.c:2024:2: note: variable 'ctinfo' is declared here enum ip_conntrack_info ctinfo; ^ 1 warning generated. nf_conntrack_update was split up into nf_conntrack_update and __nf_conntrack_update, where the assignment of ctinfo is in nf_conntrack_update but it is used in __nf_conntrack_update. Pass the value of ctinfo from nf_conntrack_update to __nf_conntrack_update so that uninitialized memory is not used and everything works properly. Fixes: ee04805ff54a ("netfilter: conntrack: make conntrack userspace helpers work again") Link: https://github.com/ClangBuiltLinux/linux/issues/1039 Signed-off-by: Nathan Chancellor Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: conntrack: comparison of unsigned in cthelper confirmation

2020-06-03T06:23:37+00:00

commit 94945ad2b330207cded0fd8d4abebde43a776dfb upstream. net/netfilter/nf_conntrack_core.c: In function nf_confirm_cthelper: net/netfilter/nf_conntrack_core.c:2117:15: warning: comparison of unsigned expression in < 0 is always false [-Wtype-limits] 2117 | if (protoff < 0 || (frag_off & htons(~0x7)) != 0) | ^ ipv6_skip_exthdr() returns a signed integer. Reported-by: Colin Ian King Fixes: 703acd70f249 ("netfilter: nfnetlink_cthelper: unbreak userspace helper support") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again

2020-06-03T06:23:37+00:00

commit d195b1d1d1196681ac4775e0361e9cca70f740c2 upstream. The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") caused that bpf_probe_read{, str}() functions were not longer available on architectures where the same logical address might have different content in kernel and user memory mapping. These architectures should use probe_read_{user,kernel}_str helpers. For backward compatibility, the problematic functions are still available on architectures where the user and kernel address spaces are not overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. At the moment, these backward compatible functions are enabled only on x86_64, arm, and arm64. Let's do it also on powerpc that has the non overlapping address space as well. Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") Signed-off-by: Petr Mladek Signed-off-by: Daniel Borkmann Acked-by: Michael Ellerman Link: https://lore.kernel.org/lkml/20200527122844.19524-1-pmladek@suse.com Signed-off-by: Greg Kroah-Hartman

bonding: Fix reference count leak in bond_sysfs_slave_add.

2020-06-03T06:23:37+00:00

commit a068aab42258e25094bc2c159948d263ed7d7a77 upstream. kobject_init_and_add() takes reference even when it fails. If this function returns an error, kobject_put() must be called to properly clean up the memory associated with the object. Previous commit "b8eb718348b8" fixed a similar problem. Fixes: 07699f9a7c8d ("bonding: add sysfs /slave dir for bond slave devices.") Signed-off-by: Qiushi Wu Acked-by: Jay Vosburgh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: dsa: declare lockless TX feature for slave ports

2020-06-03T06:23:37+00:00

commit 2b86cb8299765688c5119fd18d5f436716c81010 upstream. Be there a platform with the following layout: Regular NIC | +----> DSA master for switch port | +----> DSA master for another switch port After changing DSA back to static lockdep class keys in commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key changes"), this kernel splat can be seen: [ 13.361198] ============================================ [ 13.366524] WARNING: possible recursive locking detected [ 13.371851] 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 Not tainted [ 13.377874] -------------------------------------------- [ 13.383201] swapper/0/0 is trying to acquire lock: [ 13.388004] ffff0000668ff298 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.397879] [ 13.397879] but task is already holding lock: [ 13.403727] ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.413593] [ 13.413593] other info that might help us debug this: [ 13.420140] Possible unsafe locking scenario: [ 13.420140] [ 13.426075] CPU0 [ 13.428523] ---- [ 13.430969] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.435946] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.440924] [ 13.440924] *** DEADLOCK *** [ 13.440924] [ 13.446860] May be due to missing lock nesting notation [ 13.446860] [ 13.453668] 6 locks held by swapper/0/0: [ 13.457598] #0: ffff800010003de0 ((&idev->mc_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x400 [ 13.466593] #1: ffffd4d3fb478700 (rcu_read_lock){....}-{1:2}, at: mld_sendpack+0x0/0x560 [ 13.474803] #2: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x64/0xb10 [ 13.483886] #3: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.492793] #4: ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.503094] #5: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.512000] [ 13.512000] stack backtrace: [ 13.516369] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 [ 13.530421] Call trace: [ 13.532871] dump_backtrace+0x0/0x1d8 [ 13.536539] show_stack+0x24/0x30 [ 13.539862] dump_stack+0xe8/0x150 [ 13.543271] __lock_acquire+0x1030/0x1678 [ 13.547290] lock_acquire+0xf8/0x458 [ 13.550873] _raw_spin_lock+0x44/0x58 [ 13.554543] __dev_queue_xmit+0x84c/0xbe0 [ 13.558562] dev_queue_xmit+0x24/0x30 [ 13.562232] dsa_slave_xmit+0xe0/0x128 [ 13.565988] dev_hard_start_xmit+0xf4/0x448 [ 13.570182] __dev_queue_xmit+0x808/0xbe0 [ 13.574200] dev_queue_xmit+0x24/0x30 [ 13.577869] neigh_resolve_output+0x15c/0x220 [ 13.582237] ip6_finish_output2+0x244/0xb10 [ 13.586430] __ip6_finish_output+0x1dc/0x298 [ 13.590709] ip6_output+0x84/0x358 [ 13.594116] mld_sendpack+0x2bc/0x560 [ 13.597786] mld_ifc_timer_expire+0x210/0x390 [ 13.602153] call_timer_fn+0xcc/0x400 [ 13.605822] run_timer_softirq+0x588/0x6e0 [ 13.609927] __do_softirq+0x118/0x590 [ 13.613597] irq_exit+0x13c/0x148 [ 13.616918] __handle_domain_irq+0x6c/0xc0 [ 13.621023] gic_handle_irq+0x6c/0x160 [ 13.624779] el1_irq+0xbc/0x180 [ 13.627927] cpuidle_enter_state+0xb4/0x4d0 [ 13.632120] cpuidle_enter+0x3c/0x50 [ 13.635703] call_cpuidle+0x44/0x78 [ 13.639199] do_idle+0x228/0x2c8 [ 13.642433] cpu_startup_entry+0x2c/0x48 [ 13.646363] rest_init+0x1ac/0x280 [ 13.649773] arch_call_rest_init+0x14/0x1c [ 13.653878] start_kernel+0x490/0x4bc Lockdep keys themselves were added in commit ab92d68fc22f ("net: core: add generic lockdep keys"), and it's very likely that this splat existed since then, but I have no real way to check, since this stacked platform wasn't supported by mainline back then. >From Taehee's own words: This patch was considered that all stackable devices have LLTX flag. But the dsa doesn't have LLTX, so this splat happened. After this patch, dsa shares the same lockdep class key. On the nested dsa interface architecture, which you illustrated, the same lockdep class key will be used in __dev_queue_xmit() because dsa doesn't have LLTX. So that lockdep detects deadlock because the same lockdep class key is used recursively although actually the different locks are used. There are some ways to fix this problem. 1. using NETIF_F_LLTX flag. If possible, using the LLTX flag is a very clear way for it. But I'm so sorry I don't know whether the dsa could have LLTX or not. 2. using dynamic lockdep again. It means that each interface uses a separate lockdep class key. So, lockdep will not detect recursive locking. But this way has a problem that it could consume lockdep class key too many. Currently, lockdep can have 8192 lockdep class keys. - you can see this number with the following command. cat /proc/lockdep_stats lock-classes: 1251 [max: 8192] ... The [max: 8192] means that the maximum number of lockdep class keys. If too many lockdep class keys are registered, lockdep stops to work. So, using a dynamic(separated) lockdep class key should be considered carefully. In addition, updating lockdep class key routine might have to be existing. (lockdep_register_key(), lockdep_set_class(), lockdep_unregister_key()) 3. Using lockdep subclass. A lockdep class key could have 8 subclasses. The different subclass is considered different locks by lockdep infrastructure. But "lock-classes" is not counted by subclasses. So, it could avoid stopping lockdep infrastructure by an overflow of lockdep class keys. This approach should also have an updating lockdep class key routine. (lockdep_set_subclass()) 4. Using nonvalidate lockdep class key. The lockdep infrastructure supports nonvalidate lockdep class key type. It means this lockdep is not validated by lockdep infrastructure. So, the splat will not happen but lockdep couldn't detect real deadlock case because lockdep really doesn't validate it. I think this should be used for really special cases. (lockdep_set_novalidate_class()) Further discussion here: https://patchwork.ozlabs.org/project/netdev/patch/20200503052220.4536-2-xiyou.wangcong@gmail.com/ There appears to be no negative side-effect to declaring lockless TX for the DSA virtual interfaces, which means they handle their own locking. So that's what we do to make the splat go away. Patch tested in a wide variety of cases: unicast, multicast, PTP, etc. Fixes: ab92d68fc22f ("net: core: add generic lockdep keys") Suggested-by: Taehee Yoo Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: nexthop version of fib_info_nh_uses_dev

2020-06-03T06:23:36+00:00

commit 1fd1c768f3624a5e66766e7b4ddb9b607cd834a5 upstream. Similar to the last path, need to fix fib_info_nh_uses_dev for external nexthops to avoid referencing multiple nh_grp structs. Move the device check in fib_info_nh_uses_dev to a helper and create a nexthop version that is called if the fib_info uses an external nexthop. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

nexthop: Expand nexthop_is_multipath in a few places

2020-06-03T06:23:36+00:00

commit 0b5e2e39739e861fa5fc84ab27a35dbe62a15330 upstream. I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

nexthops: don't modify published nexthop groups

2020-06-03T06:23:36+00:00

commit 90f33bffa382598a32cc82abfeb20adc92d041b6 upstream. We must avoid modifying published nexthop groups while they might be in use, otherwise we might see NULL ptr dereferences. In order to do that we allocate 2 nexthoup group structures upon nexthop creation and swap between them when we have to delete an entry. The reason is that we can't fail nexthop group removal, so we can't handle allocation failure thus we move the extra allocation on creation where we can safely fail and return ENOMEM. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman