kernel.git/net/ipv6/route.c, branch linux-5.14.y

net: ipv4: Fix rtnexthop len when RTA_FLOW is present

2021-10-07T05:53:12Z

[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ] Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop() to get the length of rtnexthop correct. Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info") Signed-off-by: Xiao Liang Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ipv6: make exception cache less predictible

2021-09-15T08:02:31Z

[ Upstream commit a00df2caffed3883c341d5685f830434312e4a43 ] Even after commit 4785305c05b2 ("ipv6: use siphash in rt6_exception_hash()"), an attacker can still use brute force to learn some secrets from a victim linux host. One way to defeat these attacks is to make the max depth of the hash table bucket a random value. Before this patch, each bucket of the hash table used to store exceptions could contain 6 items under attack. After the patch, each bucket would contains a random number of items, between 6 and 10. The attacker can no longer infer secrets. This is slightly increasing memory size used by the hash table, we do not expect this to be a problem. Following patch is dealing with the same issue in IPv4. Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache") Signed-off-by: Eric Dumazet Reported-by: Keyu Man Cc: Wei Wang Cc: Martin KaFai Lau Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ipv6: use siphash in rt6_exception_hash()

2021-08-26T09:20:34Z

A group of security researchers brought to our attention the weakness of hash function used in rt6_exception_hash() Lets use siphash instead of Jenkins Hash, to considerably reduce security risks. Following patch deals with IPv4. Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache") Signed-off-by: Eric Dumazet Reported-by: Keyu Man Cc: Wei Wang Cc: Martin KaFai Lau Acked-by: Wei Wang Signed-off-by: David S. Miller

ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions

2021-07-20T14:25:25Z

While running the self-tests on a KASAN enabled kernel, I observed a slab-out-of-bounds splat very similar to the one reported in commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions"). We additionally need to take care of fib6_metrics initialization failure when the caller provides an nh. The fix is similar, explicitly free the route instead of calling fib6_info_release on a half-initialized object. Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net

2021-06-07T20:01:52Z

Bug fixes overlapping feature additions and refactoring, mostly. Signed-off-by: David S. Miller

ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions

2021-06-03T22:19:49Z

Reported by syzbot: HEAD commit: 90c911ad Merge tag 'fixes' of git://git.kernel.org/pub/scm.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master dashboard link: https://syzkaller.appspot.com/bug?extid=123aa35098fd3c000eb7 compiler: Debian clang version 11.0.1-2 ================================================================== BUG: KASAN: slab-out-of-bounds in fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline] BUG: KASAN: slab-out-of-bounds in fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732 Read of size 8 at addr ffff8880145c78f8 by task syz-executor.4/17760 CPU: 0 PID: 17760 Comm: syz-executor.4 Not tainted 5.12.0-rc8-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x202/0x31e lib/dump_stack.c:120 print_address_description+0x5f/0x3b0 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report+0x15c/0x200 mm/kasan/report.c:416 fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline] fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732 fib6_nh_release+0x9a/0x430 net/ipv6/route.c:3536 fib6_info_destroy_rcu+0xcb/0x1c0 net/ipv6/ip6_fib.c:174 rcu_do_batch kernel/rcu/tree.c:2559 [inline] rcu_core+0x8f6/0x1450 kernel/rcu/tree.c:2794 __do_softirq+0x372/0x7a6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu+0x22c/0x260 kernel/softirq.c:422 irq_exit_rcu+0x5/0x20 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:lock_acquire+0x1f6/0x720 kernel/locking/lockdep.c:5515 Code: f6 84 24 a1 00 00 00 02 0f 85 8d 02 00 00 f7 c3 00 02 00 00 49 bd 00 00 00 00 00 fc ff df 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 4b c7 44 3d 09 00 00 00 00 43 c7 44 3d RSP: 0018:ffffc90009e06560 EFLAGS: 00000206 RAX: 1ffff920013c0cc0 RBX: 0000000000000246 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90009e066e0 R08: dffffc0000000000 R09: fffffbfff1f992b1 R10: fffffbfff1f992b1 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920013c0cb4 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:656 [inline] ext4_get_group_info+0xea/0x340 fs/ext4/ext4.h:3231 ext4_mb_prefetch+0x123/0x5d0 fs/ext4/mballoc.c:2212 ext4_mb_regular_allocator+0x8a5/0x28f0 fs/ext4/mballoc.c:2379 ext4_mb_new_blocks+0xc6e/0x24f0 fs/ext4/mballoc.c:4982 ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c:4238 ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638 ext4_getblk+0x187/0x6c0 fs/ext4/inode.c:848 ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900 ext4_append+0x1a4/0x360 fs/ext4/namei.c:67 ext4_init_new_dir+0x337/0xa10 fs/ext4/namei.c:2768 ext4_mkdir+0x4b8/0xc00 fs/ext4/namei.c:2814 vfs_mkdir+0x45b/0x640 fs/namei.c:3819 ovl_do_mkdir fs/overlayfs/overlayfs.h:161 [inline] ovl_mkdir_real+0x53/0x1a0 fs/overlayfs/dir.c:146 ovl_create_real+0x280/0x490 fs/overlayfs/dir.c:193 ovl_workdir_create+0x425/0x600 fs/overlayfs/super.c:788 ovl_make_workdir+0xed/0x1140 fs/overlayfs/super.c:1355 ovl_get_workdir fs/overlayfs/super.c:1492 [inline] ovl_fill_super+0x39ee/0x5370 fs/overlayfs/super.c:2035 mount_nodev+0x52/0xe0 fs/super.c:1413 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3233 do_mount fs/namespace.c:3246 [inline] __do_sys_mount fs/namespace.c:3454 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3431 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f68f2b87188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9 RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 000000000040000a RBP: 00000000004bfbb9 R08: 0000000020000100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffe19002dff R14: 00007f68f2b87300 R15: 0000000000022000 Allocated by task 17768: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc+0xc2/0xf0 mm/kasan/common.c:506 kasan_kmalloc include/linux/kasan.h:233 [inline] __kmalloc+0xb4/0x380 mm/slub.c:4055 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:684 [inline] fib6_info_alloc+0x2c/0xd0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x55d/0x1a10 net/ipv6/route.c:3638 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x27/0x50 mm/kasan/common.c:38 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345 __call_rcu kernel/rcu/tree.c:3039 [inline] call_rcu+0x1b1/0xa30 kernel/rcu/tree.c:3114 fib6_info_release include/net/ip6_fib.h:337 [inline] ip6_route_info_create+0x10c4/0x1a10 net/ipv6/route.c:3718 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Second to last potentially related work creation: kasan_save_stack+0x27/0x50 mm/kasan/common.c:38 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345 insert_work+0x54/0x400 kernel/workqueue.c:1331 __queue_work+0x981/0xcc0 kernel/workqueue.c:1497 queue_work_on+0x111/0x200 kernel/workqueue.c:1524 queue_work include/linux/workqueue.h:507 [inline] call_usermodehelper_exec+0x283/0x470 kernel/umh.c:433 kobject_uevent_env+0x1349/0x1730 lib/kobject_uevent.c:617 kvm_uevent_notify_change+0x309/0x3b0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4809 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:877 [inline] kvm_put_kvm+0x9c/0xd10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:920 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3120 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x10b/0x1e0 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x26/0x70 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff8880145c7800 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 56 bytes to the right of 192-byte region [ffff8880145c7800, ffff8880145c78c0) The buggy address belongs to the page: page:ffffea00005171c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x145c7 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea00006474c0 0000000200000002 ffff888010c41a00 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880145c7780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880145c7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880145c7880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880145c7900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880145c7980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== In the ip6_route_info_create function, in the case that the nh pointer is not NULL, the fib6_nh in fib6_info has not been allocated. Therefore, when trying to free fib6_info in this error case using fib6_info_release, the function will call fib6_info_destroy_rcu, which it will access fib6_nh_release(f6i->fib6_nh); However, f6i->fib6_nh doesn't have any refcount yet given the lack of allocation causing the reported memory issue above. Therefore, releasing the empty pointer directly instead would be the solution. Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info") Fixes: 706ec91916462 ("ipv6: Fix nexthop refcnt leak when creating ipv6 route info") Signed-off-by: Coco Li Cc: David Ahern Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: Add custom multipath hash policy

2021-05-18T20:27:32Z

Add a new multipath hash policy where the packet fields used for hash calculation are determined by user space via the fib_multipath_hash_fields sysctl that was introduced in the previous patch. The current set of available packet fields includes both outer and inner fields, which requires two invocations of the flow dissector. Avoid unnecessary dissection of the outer or inner flows by skipping dissection if none of the outer or inner fields are required. In accordance with the existing policies, when an skb is not available, packet fields are extracted from the provided flow key. In which case, only outer fields are considered. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: Calculate multipath hash inside switch statement

2021-05-18T20:27:32Z

A subsequent patch will add another multipath hash policy where the multipath hash is calculated directly by the policy specific code and not outside of the switch statement. Prepare for this change by moving the multipath hash calculation inside the switch statement. No functional changes intended. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-04-10T03:48:35Z

Conflicts: MAINTAINERS - keep Chandrasekar drivers/net/ethernet/mellanox/mlx5/core/en_main.c - simple fix + trust the code re-added to param.c in -next is fine include/linux/bpf.h - trivial include/linux/ethtool.h - trivial, fix kdoc while at it include/linux/skmsg.h - move to relevant place in tcp.c, comment re-wrapped net/core/skmsg.c - add the sk = sk // sk = NULL around calls net/tipc/crypto.c - trivial Signed-off-by: Jakub Kicinski

net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh

2021-04-08T23:41:46Z

nlh is being checked for validtity two times when it is dereferenced in this function. Check for validity again when updating the flags through nlh pointer to make the dereferencing safe. CC: Addresses-Coverity: ("NULL pointer dereference") Signed-off-by: Muhammad Usama Anjum Signed-off-by: David S. Miller