kernel/linux.git/net/tipc/netlink_compat.c, branch linux-4.16.y

tipc: Fix missing RTNL lock protection during setting link properties

2018-02-14T19:46:33+00:00

Currently when user changes link properties, TIPC first checks if user's command message contains media name or bearer name through tipc_media_find() or tipc_bearer_find() which is protected by RTNL lock. But when tipc_nl_compat_link_set() conducts the checking with the two functions, it doesn't hold RTNL lock at all, as a result, the following complaints were reported: audit: type=1400 audit(1514679888.244:9): avc: denied { write } for pid=3194 comm="syzkaller021477" path="socket:[11143]" dev="sockfs" ino=11143 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 Reviewed-by: Kirill Tkhai ============================= WARNING: suspicious RCU usage 4.15.0-rc5+ #152 Not tainted ----------------------------- net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syzkaller021477/3194: #0: (cb_lock){++++}, at: [<00000000d20133ea>] genl_rcv+0x19/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000fcc5d1bc>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000fcc5d1bc>] genl_rcv_msg+0x115/0x140 net/netlink/genetlink.c:622 stack backtrace: CPU: 1 PID: 3194 Comm: syzkaller021477 Not tainted 4.15.0-rc5+ #152 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585 tipc_bearer_find+0x2b4/0x3b0 net/tipc/bearer.c:177 tipc_nl_compat_link_set+0x329/0x9f0 net/tipc/netlink_compat.c:729 __tipc_nl_compat_doit net/tipc/netlink_compat.c:288 [inline] tipc_nl_compat_doit+0x15b/0x660 net/tipc/netlink_compat.c:335 tipc_nl_compat_handle net/tipc/netlink_compat.c:1119 [inline] tipc_nl_compat_recv+0x112f/0x18f0 net/tipc/netlink_compat.c:1201 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:599 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624 netlink_rcv_skb+0x21e/0x460 net/netlink/af_netlink.c:2408 genl_rcv+0x28/0x40 net/netlink/genetlink.c:635 netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1301 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1864 sock_sendmsg_nosec net/socket.c:636 [inline] sock_sendmsg+0xca/0x110 net/socket.c:646 sock_write_iter+0x31a/0x5d0 net/socket.c:915 call_write_iter include/linux/fs.h:1772 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 In order to correct the mistake, __tipc_nl_compat_doit() has been protected by RTNL lock, which means the whole operation of setting bearer/media properties is under RTNL protection. Signed-off-by: Ying Xue Reported-by: syzbot Signed-off-by: David S. Miller

tipc: Refactor __tipc_nl_compat_doit

2018-02-14T19:46:32+00:00

As preparation for adding RTNL to make (*cmd->transcode)() and (*cmd->transcode)() constantly protected by RTNL lock, we move out of memory allocations existing between them as many as possible so that the time of holding RTNL can be minimized in __tipc_nl_compat_doit(). Signed-off-by: Ying Xue Signed-off-by: David S. Miller

net: tipc: constify genl_ops

2017-08-24T05:31:38+00:00

genl_ops are not supposed to change at runtime. All functions working with genl_ops provided by work with const genl_ops. So mark the non-const structs as const. Signed-off-by: Arvind Yadav Signed-off-by: David S. Miller

tipc: fix use-after-free

2017-08-18T22:59:29+00:00

syszkaller reported use-after-free in tipc [1] When msg->rep skb is freed, set the pointer to NULL, so that caller does not free it again. [1] ================================================================== BUG: KASAN: use-after-free in skb_push+0xd4/0xe0 net/core/skbuff.c:1466 Read of size 8 at addr ffff8801c6e71e90 by task syz-executor5/4115 CPU: 1 PID: 4115 Comm: syz-executor5 Not tainted 4.13.0-rc4+ #32 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 skb_push+0xd4/0xe0 net/core/skbuff.c:1466 tipc_nl_compat_recv+0x833/0x18f0 net/tipc/netlink_compat.c:1209 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x4512e9 RSP: 002b:00007f3bc8184c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004512e9 RDX: 0000000000000020 RSI: 0000000020fdb000 RDI: 0000000000000006 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b5e76 R13: 00007f3bc8184b48 R14: 00000000004b5e86 R15: 0000000000000000 Allocated by task 4115: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc_node+0x13d/0x750 mm/slab.c:3651 __alloc_skb+0xf1/0x740 net/core/skbuff.c:219 alloc_skb include/linux/skbuff.h:903 [inline] tipc_tlv_alloc+0x26/0xb0 net/tipc/netlink_compat.c:148 tipc_nl_compat_dumpit+0xf2/0x3c0 net/tipc/netlink_compat.c:248 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline] tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 4115: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x77/0x280 mm/slab.c:3763 kfree_skbmem+0x1a1/0x1d0 net/core/skbuff.c:622 __kfree_skb net/core/skbuff.c:682 [inline] kfree_skb+0x165/0x4c0 net/core/skbuff.c:699 tipc_nl_compat_dumpit+0x36a/0x3c0 net/tipc/netlink_compat.c:260 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline] tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801c6e71dc0 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 208 bytes inside of 224-byte region [ffff8801c6e71dc0, ffff8801c6e71ea0) The buggy address belongs to the page: page:ffffea00071b9c40 count:1 mapcount:0 mapping:ffff8801c6e71000 index:0x0 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801c6e71000 0000000000000000 000000010000000c raw: ffffea0007224a20 ffff8801d98caf48 ffff8801d9e79040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c6e71d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801c6e71e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c6e71e80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801c6e71f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c6e71f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Cc: Jon Maloy Cc: Ying Xue Signed-off-by: David S. Miller

netlink: pass extended ACK struct to parsing functions

2017-04-13T17:58:22+00:00

Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

genetlink: mark families as __ro_after_init

2016-10-27T20:16:09+00:00

Now genl_register_family() is the only thing (other than the users themselves, perhaps, but I didn't find any doing that) writing to the family struct. In all families that I found, genl_register_family() is only called from __init functions (some indirectly, in which case I've add __init annotations to clarifly things), so all can actually be marked __ro_after_init. This protects the data structure from accidental corruption. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

genetlink: statically initialize families

2016-10-27T20:16:09+00:00

Instead of providing macros/inline functions to initialize the families, make all users initialize them statically and get rid of the macros. This reduces the kernel code size by about 1.6k on x86-64 (with allyesconfig). Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

genetlink: no longer support using static family IDs

2016-10-27T20:16:09+00:00

Static family IDs have never really been used, the only use case was the workaround I introduced for those users that assumed their family ID was also their multicast group ID. Additionally, because static family IDs would never be reserved by the generic netlink code, using a relatively low ID would only work for built-in families that can be registered immediately after generic netlink is started, which is basically only the control family (apart from the workaround code, which I also had to add code for so it would reserve those IDs) Thus, anything other than GENL_ID_GENERATE is flawed and luckily not used except in the cases I mentioned. Move those workarounds into a few lines of code, and then get rid of GENL_ID_GENERATE entirely, making it more robust. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

tipc: fix nl compat regression for link statistics

2016-07-01T20:47:38+00:00

Fix incorrect use of nla_strlcpy() where the first NLA_HDRLEN bytes of the link name where left out. Making the output of tipc-config -ls look something like: Link statistics: dcast-link 1:data0-1.1.2:data0 1:data0-1.1.3:data0 Also, for the record, the patch that introduce this regression claims "Sending the whole object out can cause a leak". Which isn't very likely as this is a compat layer, where the data we are parsing is generated by us and we know the string to be NULL terminated. But you can of course never be to secure. Fixes: 5d2be1422e02 (tipc: fix an infoleak in tipc_nl_compat_link_dump) Signed-off-by: Richard Alpe Signed-off-by: David S. Miller

tipc: fix an infoleak in tipc_nl_compat_link_dump

2016-06-03T04:32:37+00:00

link_info.str is a char array of size 60. Memory after the NULL byte is not initialized. Sending the whole object out can cause a leak. Signed-off-by: Kangjie Lu Signed-off-by: David S. Miller