linux-stable.git/net, branch v4.14.331 Linux kernel stable tree net: sched: fix race condition in qdisc_graft() 2023-11-28T16:45:46+00:00 Eric Dumazet edumazet@google.com 2022-10-18T20:32:58+00:00 42c50c7efcd1d263455438b81fe9388e685bfb66 commit ebda44da44f6f309d302522b049f43d6f829f7aa upstream. We had one syzbot report [1] in syzbot queue for a while. I was waiting for more occurrences and/or a repro but Dmitry Vyukov spotted the issue right away. <quoting Dmitry> qdisc_graft() drops reference to qdisc in notify_and_destroy while it's still assigned to dev->qdisc </quoting> Indeed, RCU rules are clear when replacing a data structure. The visible pointer (dev->qdisc in this case) must be updated to the new object _before_ RCU grace period is started (qdisc_put(old) in this case). [1] BUG: KASAN: use-after-free in __tcf_qdisc_find.part.0+0xa3a/0xac0 net/sched/cls_api.c:1066 Read of size 4 at addr ffff88802065e038 by task syz-executor.4/21027 CPU: 0 PID: 21027 Comm: syz-executor.4 Not tainted 6.0.0-rc3-syzkaller-00363-g7726d4c3e60b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 __tcf_qdisc_find.part.0+0xa3a/0xac0 net/sched/cls_api.c:1066 __tcf_qdisc_find net/sched/cls_api.c:1051 [inline] tc_new_tfilter+0x34f/0x2200 net/sched/cls_api.c:2018 rtnetlink_rcv_msg+0x955/0xca0 net/core/rtnetlink.c:6081 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5efaa89279 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5efbc31168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5efab9bf80 RCX: 00007f5efaa89279 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00007f5efaae32e9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5efb0cfb1f R14: 00007f5efbc31300 R15: 0000000000022000 </TASK> Allocated by task 21027: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc_node include/linux/slab.h:623 [inline] kzalloc_node include/linux/slab.h:744 [inline] qdisc_alloc+0xb0/0xc50 net/sched/sch_generic.c:938 qdisc_create_dflt+0x71/0x4a0 net/sched/sch_generic.c:997 attach_one_default_qdisc net/sched/sch_generic.c:1152 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2437 [inline] attach_default_qdiscs net/sched/sch_generic.c:1170 [inline] dev_activate+0x760/0xcd0 net/sched/sch_generic.c:1229 __dev_open+0x393/0x4d0 net/core/dev.c:1441 __dev_change_flags+0x583/0x750 net/core/dev.c:8556 rtnl_configure_link+0xee/0x240 net/core/rtnetlink.c:3189 rtnl_newlink_create net/core/rtnetlink.c:3371 [inline] __rtnl_newlink+0x10b8/0x17e0 net/core/rtnetlink.c:3580 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 21020: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x580 mm/slub.c:4562 rcu_do_batch kernel/rcu/tree.c:2245 [inline] rcu_core+0x7b5/0x1890 kernel/rcu/tree.c:2505 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793 qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:1083 notify_and_destroy net/sched/sch_api.c:1012 [inline] qdisc_graft+0xeb1/0x1270 net/sched/sch_api.c:1084 tc_modify_qdisc+0xbb7/0x1a00 net/sched/sch_api.c:1671 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322 neigh_destroy+0x431/0x630 net/core/neighbour.c:912 neigh_release include/net/neighbour.h:454 [inline] neigh_cleanup_and_release+0x1f8/0x330 net/core/neighbour.c:103 neigh_del net/core/neighbour.c:225 [inline] neigh_remove_one+0x37d/0x460 net/core/neighbour.c:246 neigh_forced_gc net/core/neighbour.c:276 [inline] neigh_alloc net/core/neighbour.c:447 [inline] ___neigh_create+0x18b5/0x29a0 net/core/neighbour.c:642 ip6_finish_output2+0xfb8/0x1520 net/ipv6/ip6_output.c:125 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x690/0x1160 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1ed/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] mld_sendpack+0xa09/0xe70 net/ipv6/mcast.c:1820 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x71c/0xdc0 net/ipv6/mcast.c:2653 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88802065e000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 56 bytes inside of 1024-byte region [ffff88802065e000, ffff88802065e400) The buggy address belongs to the physical page: page:ffffea0000819600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20658 head:ffffea0000819600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011841dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3523, tgid 3523 (sshd), ts 41495190986, free_ts 41417713212 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x2f2/0x380 mm/slub.c:4955 kmalloc_reserve net/core/skbuff.c:358 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:430 alloc_skb_fclone include/linux/skbuff.h:1307 [inline] tcp_stream_alloc_skb+0x38/0x580 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xc36/0x2f80 net/ipv4/tcp.c:1325 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1483 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_write_iter+0x291/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 ksys_write+0x1e8/0x250 fs/read_write.c:631 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3268 kmem_cache_zalloc include/linux/slab.h:723 [inline] alloc_buffer_head+0x20/0x140 fs/buffer.c:2974 alloc_page_buffers+0x280/0x790 fs/buffer.c:829 create_empty_buffers+0x2c/0xee0 fs/buffer.c:1558 ext4_block_write_begin+0x1004/0x1530 fs/ext4/inode.c:1074 ext4_da_write_begin+0x422/0xae0 fs/ext4/inode.c:2996 generic_perform_write+0x246/0x560 mm/filemap.c:3738 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:270 ext4_file_write_iter+0x44a/0x1660 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 Fixes: af356afa010f ("net_sched: reintroduce dev->qdisc for use by sch_api") Reported-by: syzbot <syzkaller@googlegroups.com> Diagnosed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20221018203258.2793282-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ mheyne: removed rtnl_dereference due to missing commit 5891cd5ec46c ("net_sched: add __rcu annotation to netdev->qdisc") ] Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ebda44da44f6f309d302522b049f43d6f829f7aa upstream.

We had one syzbot report [1] in syzbot queue for a while.
I was waiting for more occurrences and/or a repro but
Dmitry Vyukov spotted the issue right away.

<quoting Dmitry>
qdisc_graft() drops reference to qdisc in notify_and_destroy
while it's still assigned to dev->qdisc
</quoting>

Indeed, RCU rules are clear when replacing a data structure.
The visible pointer (dev->qdisc in this case) must be updated
to the new object _before_ RCU grace period is started
(qdisc_put(old) in this case).

[1]
BUG: KASAN: use-after-free in __tcf_qdisc_find.part.0+0xa3a/0xac0 net/sched/cls_api.c:1066
Read of size 4 at addr ffff88802065e038 by task syz-executor.4/21027

CPU: 0 PID: 21027 Comm: syz-executor.4 Not tainted 6.0.0-rc3-syzkaller-00363-g7726d4c3e60b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
__tcf_qdisc_find.part.0+0xa3a/0xac0 net/sched/cls_api.c:1066
__tcf_qdisc_find net/sched/cls_api.c:1051 [inline]
tc_new_tfilter+0x34f/0x2200 net/sched/cls_api.c:2018
rtnetlink_rcv_msg+0x955/0xca0 net/core/rtnetlink.c:6081
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
__sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5efaa89279
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5efbc31168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5efab9bf80 RCX: 00007f5efaa89279
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 00007f5efaae32e9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5efb0cfb1f R14: 00007f5efbc31300 R15: 0000000000022000
</TASK>

Allocated by task 21027:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
____kasan_kmalloc mm/kasan/common.c:516 [inline]
____kasan_kmalloc mm/kasan/common.c:475 [inline]
__kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525
kmalloc_node include/linux/slab.h:623 [inline]
kzalloc_node include/linux/slab.h:744 [inline]
qdisc_alloc+0xb0/0xc50 net/sched/sch_generic.c:938
qdisc_create_dflt+0x71/0x4a0 net/sched/sch_generic.c:997
attach_one_default_qdisc net/sched/sch_generic.c:1152 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2437 [inline]
attach_default_qdiscs net/sched/sch_generic.c:1170 [inline]
dev_activate+0x760/0xcd0 net/sched/sch_generic.c:1229
__dev_open+0x393/0x4d0 net/core/dev.c:1441
__dev_change_flags+0x583/0x750 net/core/dev.c:8556
rtnl_configure_link+0xee/0x240 net/core/rtnetlink.c:3189
rtnl_newlink_create net/core/rtnetlink.c:3371 [inline]
__rtnl_newlink+0x10b8/0x17e0 net/core/rtnetlink.c:3580
rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
__sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 21020:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:45
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:367 [inline]
____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329
kasan_slab_free include/linux/kasan.h:200 [inline]
slab_free_hook mm/slub.c:1754 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
slab_free mm/slub.c:3534 [inline]
kfree+0xe2/0x580 mm/slub.c:4562
rcu_do_batch kernel/rcu/tree.c:2245 [inline]
rcu_core+0x7b5/0x1890 kernel/rcu/tree.c:2505
__do_softirq+0x1d3/0x9c6 kernel/softirq.c:571

Last potentially related work creation:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
__kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
call_rcu+0x99/0x790 kernel/rcu/tree.c:2793
qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:1083
notify_and_destroy net/sched/sch_api.c:1012 [inline]
qdisc_graft+0xeb1/0x1270 net/sched/sch_api.c:1084
tc_modify_qdisc+0xbb7/0x1a00 net/sched/sch_api.c:1671
rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
__sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
__kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322
neigh_destroy+0x431/0x630 net/core/neighbour.c:912
neigh_release include/net/neighbour.h:454 [inline]
neigh_cleanup_and_release+0x1f8/0x330 net/core/neighbour.c:103
neigh_del net/core/neighbour.c:225 [inline]
neigh_remove_one+0x37d/0x460 net/core/neighbour.c:246
neigh_forced_gc net/core/neighbour.c:276 [inline]
neigh_alloc net/core/neighbour.c:447 [inline]
___neigh_create+0x18b5/0x29a0 net/core/neighbour.c:642
ip6_finish_output2+0xfb8/0x1520 net/ipv6/ip6_output.c:125
__ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
ip6_finish_output+0x690/0x1160 net/ipv6/ip6_output.c:206
NF_HOOK_COND include/linux/netfilter.h:296 [inline]
ip6_output+0x1ed/0x540 net/ipv6/ip6_output.c:227
dst_output include/net/dst.h:451 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
mld_sendpack+0xa09/0xe70 net/ipv6/mcast.c:1820
mld_send_cr net/ipv6/mcast.c:2121 [inline]
mld_ifc_work+0x71c/0xdc0 net/ipv6/mcast.c:2653
process_one_work+0x991/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The buggy address belongs to the object at ffff88802065e000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 56 bytes inside of
1024-byte region [ffff88802065e000, ffff88802065e400)

The buggy address belongs to the physical page:
page:ffffea0000819600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20658
head:ffffea0000819600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011841dc0
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3523, tgid 3523 (sshd), ts 41495190986, free_ts 41417713212
prep_new_page mm/page_alloc.c:2532 [inline]
get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
__alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:1824 [inline]
allocate_slab+0x27e/0x3d0 mm/slub.c:1969
new_slab mm/slub.c:2029 [inline]
___slab_alloc+0x7f1/0xe10 mm/slub.c:3031
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
slab_alloc_node mm/slub.c:3209 [inline]
__kmalloc_node_track_caller+0x2f2/0x380 mm/slub.c:4955
kmalloc_reserve net/core/skbuff.c:358 [inline]
__alloc_skb+0xd9/0x2f0 net/core/skbuff.c:430
alloc_skb_fclone include/linux/skbuff.h:1307 [inline]
tcp_stream_alloc_skb+0x38/0x580 net/ipv4/tcp.c:861
tcp_sendmsg_locked+0xc36/0x2f80 net/ipv4/tcp.c:1325
tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1483
inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
sock_write_iter+0x291/0x3d0 net/socket.c:1108
call_write_iter include/linux/fs.h:2187 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x9e9/0xdd0 fs/read_write.c:578
ksys_write+0x1e8/0x250 fs/read_write.c:631
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1449 [inline]
free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
free_unref_page_prepare mm/page_alloc.c:3380 [inline]
free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
__unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447
kasan_slab_alloc include/linux/kasan.h:224 [inline]
slab_post_alloc_hook mm/slab.h:727 [inline]
slab_alloc_node mm/slub.c:3243 [inline]
slab_alloc mm/slub.c:3251 [inline]
__kmem_cache_alloc_lru mm/slub.c:3258 [inline]
kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3268
kmem_cache_zalloc include/linux/slab.h:723 [inline]
alloc_buffer_head+0x20/0x140 fs/buffer.c:2974
alloc_page_buffers+0x280/0x790 fs/buffer.c:829
create_empty_buffers+0x2c/0xee0 fs/buffer.c:1558
ext4_block_write_begin+0x1004/0x1530 fs/ext4/inode.c:1074
ext4_da_write_begin+0x422/0xae0 fs/ext4/inode.c:2996
generic_perform_write+0x246/0x560 mm/filemap.c:3738
ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:270
ext4_file_write_iter+0x44a/0x1660 fs/ext4/file.c:679
call_write_iter include/linux/fs.h:2187 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x9e9/0xdd0 fs/read_write.c:578

Fixes: af356afa010f ("net_sched: reintroduce dev->qdisc for use by sch_api")
Reported-by: syzbot <syzkaller@googlegroups.com>
Diagnosed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221018203258.2793282-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ mheyne: removed rtnl_dereference due to missing commit 5891cd5ec46c
  ("net_sched: add __rcu annotation to netdev->qdisc") ]
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: annotate data-races around sk->sk_dst_pending_confirm 2023-11-28T16:45:43+00:00 Eric Dumazet edumazet@google.com 2023-09-21T20:28:18+00:00 541184f4abcf40e272ec06b72d0a8a67b903566b [ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ] This field can be read or written without socket lock being held. Add annotations to avoid load-store tearing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ]

This field can be read or written without socket lock being held.

Add annotations to avoid load-store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: mac80211: don't return unset power in ieee80211_get_tx_power() 2023-11-28T16:45:42+00:00 Ping-Ke Shih pkshih@realtek.com 2023-02-03T02:36:36+00:00 1571120c44dbe5757aee1612c5b6097cdc42710f [ Upstream commit e160ab85166e77347d0cbe5149045cb25e83937f ] We can get a UBSAN warning if ieee80211_get_tx_power() returns the INT_MIN value mac80211 internally uses for "unset power level". UBSAN: signed-integer-overflow in net/wireless/nl80211.c:3816:5 -2147483648 * 100 cannot be represented in type 'int' CPU: 0 PID: 20433 Comm: insmod Tainted: G WC OE Call Trace: dump_stack+0x74/0x92 ubsan_epilogue+0x9/0x50 handle_overflow+0x8d/0xd0 __ubsan_handle_mul_overflow+0xe/0x10 nl80211_send_iface+0x688/0x6b0 [cfg80211] [...] cfg80211_register_wdev+0x78/0xb0 [cfg80211] cfg80211_netdev_notifier_call+0x200/0x620 [cfg80211] [...] ieee80211_if_add+0x60e/0x8f0 [mac80211] ieee80211_register_hw+0xda5/0x1170 [mac80211] In this case, simply return an error instead, to indicate that no data is available. Cc: Zong-Zhe Yang <kevin_yang@realtek.com> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@realtek.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e160ab85166e77347d0cbe5149045cb25e83937f ]

We can get a UBSAN warning if ieee80211_get_tx_power() returns the
INT_MIN value mac80211 internally uses for "unset power level".

 UBSAN: signed-integer-overflow in net/wireless/nl80211.c:3816:5
 -2147483648 * 100 cannot be represented in type 'int'
 CPU: 0 PID: 20433 Comm: insmod Tainted: G        WC OE
 Call Trace:
  dump_stack+0x74/0x92
  ubsan_epilogue+0x9/0x50
  handle_overflow+0x8d/0xd0
  __ubsan_handle_mul_overflow+0xe/0x10
  nl80211_send_iface+0x688/0x6b0 [cfg80211]
  [...]
  cfg80211_register_wdev+0x78/0xb0 [cfg80211]
  cfg80211_netdev_notifier_call+0x200/0x620 [cfg80211]
  [...]
  ieee80211_if_add+0x60e/0x8f0 [mac80211]
  ieee80211_register_hw+0xda5/0x1170 [mac80211]

In this case, simply return an error instead, to indicate
that no data is available.

Cc: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@realtek.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: xt_recent: fix (increase) ipv6 literal buffer length 2023-11-20T09:27:35+00:00 Maciej Żenczykowski zenczykowski@gmail.com 2023-11-05T19:56:00+00:00 841cce409bb7fe8fa3812f607ced49176c53bb1c [ Upstream commit 7b308feb4fd2d1c06919445c65c8fbf8e9fd1781 ] in6_pton() supports 'low-32-bit dot-decimal representation' (this is useful with DNS64/NAT64 networks for example): # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:1.2.3.4 > /proc/self/net/xt_recent/DEFAULT # cat /proc/self/net/xt_recent/DEFAULT src=aaaa:bbbb:cccc:dddd:eeee:ffff:0102:0304 ttl: 0 last_seen: 9733848829 oldest_pkt: 1 9733848829 but the provided buffer is too short: # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:255.255.255.255 > /proc/self/net/xt_recent/DEFAULT -bash: echo: write error: Invalid argument Fixes: 079aa88fe717 ("netfilter: xt_recent: IPv6 support") Signed-off-by: Maciej Żenczykowski <zenczykowski@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7b308feb4fd2d1c06919445c65c8fbf8e9fd1781 ]

in6_pton() supports 'low-32-bit dot-decimal representation'
(this is useful with DNS64/NAT64 networks for example):

  # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:1.2.3.4 > /proc/self/net/xt_recent/DEFAULT
  # cat /proc/self/net/xt_recent/DEFAULT
  src=aaaa:bbbb:cccc:dddd:eeee:ffff:0102:0304 ttl: 0 last_seen: 9733848829 oldest_pkt: 1 9733848829

but the provided buffer is too short:

  # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:255.255.255.255 > /proc/self/net/xt_recent/DEFAULT
  -bash: echo: write error: Invalid argument

Fixes: 079aa88fe717 ("netfilter: xt_recent: IPv6 support")
Signed-off-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses. 2023-11-20T09:27:35+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2023-10-30T20:10:42+00:00 cc0e7678af9ce6beadb5e851d253e2d6a81f426e [ Upstream commit 23be1e0e2a83a8543214d2599a31d9a2185a796b ] Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child sockets") introduced security_inet_conn_request() in some functions where reqsk is allocated. The hook is added just after the allocation, so reqsk's IPv6 remote address was not initialised then. However, SELinux/Smack started to read it in netlbl_req_setattr() after commit e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm."). Commit 284904aa7946 ("lsm: Relocate the IPv4 security_inet_conn_request() hooks") fixed that kind of issue only in TCPv4 because IPv6 labeling was not supported at that time. Finally, the same issue was introduced again in IPv6. Let's apply the same fix on DCCPv6 and TCPv6. Fixes: e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 23be1e0e2a83a8543214d2599a31d9a2185a796b ]

Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child
sockets") introduced security_inet_conn_request() in some functions
where reqsk is allocated.  The hook is added just after the allocation,
so reqsk's IPv6 remote address was not initialised then.

However, SELinux/Smack started to read it in netlbl_req_setattr()
after commit e1adea927080 ("calipso: Allow request sockets to be
relabelled by the lsm.").

Commit 284904aa7946 ("lsm: Relocate the IPv4 security_inet_conn_request()
hooks") fixed that kind of issue only in TCPv4 because IPv6 labeling was
not supported at that time.  Finally, the same issue was introduced again
in IPv6.

Let's apply the same fix on DCCPv6 and TCPv6.

Fixes: e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dccp: Call security_inet_conn_request() after setting IPv4 addresses. 2023-11-20T09:27:35+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2023-10-30T20:10:41+00:00 5174aa9bca8ae59745b203b265e784b23cdc2d48 [ Upstream commit fa2df45af13091f76b89adb84a28f13818d5d631 ] Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child sockets") introduced security_inet_conn_request() in some functions where reqsk is allocated. The hook is added just after the allocation, so reqsk's IPv4 remote address was not initialised then. However, SELinux/Smack started to read it in netlbl_req_setattr() after the cited commits. This bug was partially fixed by commit 284904aa7946 ("lsm: Relocate the IPv4 security_inet_conn_request() hooks"). This patch fixes the last bug in DCCPv4. Fixes: 389fb800ac8b ("netlabel: Label incoming TCP connections correctly in SELinux") Fixes: 07feee8f812f ("netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fa2df45af13091f76b89adb84a28f13818d5d631 ]

Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child
sockets") introduced security_inet_conn_request() in some functions
where reqsk is allocated.  The hook is added just after the allocation,
so reqsk's IPv4 remote address was not initialised then.

However, SELinux/Smack started to read it in netlbl_req_setattr()
after the cited commits.

This bug was partially fixed by commit 284904aa7946 ("lsm: Relocate
the IPv4 security_inet_conn_request() hooks").

This patch fixes the last bug in DCCPv4.

Fixes: 389fb800ac8b ("netlabel: Label incoming TCP connections correctly in SELinux")
Fixes: 07feee8f812f ("netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING 2023-11-20T09:27:35+00:00 Shigeru Yoshida syoshida@redhat.com 2023-10-30T07:55:40+00:00 6744008c354bca2e4686a5b6056ee6b535d9f67d [ Upstream commit 19b3f72a41a8751e26bffc093bb7e1cef29ad579 ] syzbot reported the following uninit-value access issue [1]: ===================================================== BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline] BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756 strlen lib/string.c:418 [inline] strstr+0xb8/0x2f0 lib/string.c:756 tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595 genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd TIPC bearer-related names including link names must be null-terminated strings. If a link name which is not null-terminated is passed through netlink, strstr() and similar functions can cause buffer overrun. This causes the above issue. This patch changes the nla_policy for bearer-related names from NLA_STRING to NLA_NUL_STRING. This resolves the issue by ensuring that only null-terminated strings are accepted as bearer-related names. syzbot reported similar uninit-value issue related to bearer names [2]. The root cause of this issue is that a non-null-terminated bearer name was passed. This patch also resolved this issue. Fixes: 7be57fc69184 ("tipc: add link get/dump to new netlink api") Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") Reported-and-tested-by: syzbot+5138ca807af9d2b42574@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=5138ca807af9d2b42574 [1] Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 [2] Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231030075540.3784537-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 19b3f72a41a8751e26bffc093bb7e1cef29ad579 ]

syzbot reported the following uninit-value access issue [1]:

=====================================================
BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline]
BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756
 strlen lib/string.c:418 [inline]
 strstr+0xb8/0x2f0 lib/string.c:756
 tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595
 genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
 genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066
 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545
 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
 __sys_sendmsg net/socket.c:2624 [inline]
 __do_sys_sendmsg net/socket.c:2633 [inline]
 __se_sys_sendmsg net/socket.c:2631 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
 slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
 __alloc_skb+0x318/0x740 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1286 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline]
 netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
 __sys_sendmsg net/socket.c:2624 [inline]
 __do_sys_sendmsg net/socket.c:2633 [inline]
 __se_sys_sendmsg net/socket.c:2631 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

TIPC bearer-related names including link names must be null-terminated
strings. If a link name which is not null-terminated is passed through
netlink, strstr() and similar functions can cause buffer overrun. This
causes the above issue.

This patch changes the nla_policy for bearer-related names from NLA_STRING
to NLA_NUL_STRING. This resolves the issue by ensuring that only
null-terminated strings are accepted as bearer-related names.

syzbot reported similar uninit-value issue related to bearer names [2]. The
root cause of this issue is that a non-null-terminated bearer name was
passed. This patch also resolved this issue.

Fixes: 7be57fc69184 ("tipc: add link get/dump to new netlink api")
Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api")
Reported-and-tested-by: syzbot+5138ca807af9d2b42574@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5138ca807af9d2b42574 [1]
Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 [2]
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231030075540.3784537-1-syoshida@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
llc: verify mac len before reading mac header 2023-11-20T09:27:35+00:00 Willem de Bruijn willemb@google.com 2023-10-25T23:42:38+00:00 900a4418e3f66a32db6baaf23f92b99c20ae6535 [ Upstream commit 7b3ba18703a63f6fd487183b9262b08e5632da1b ] LLC reads the mac header with eth_hdr without verifying that the skb has an Ethernet header. Syzbot was able to enter llc_rcv on a tun device. Tun can insert packets without mac len and with user configurable skb->protocol (passing a tun_pi header when not configuring IFF_NO_PI). BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002 Add a mac_len test before all three eth_hdr(skb) calls under net/llc. There are further uses in include/net/llc_pdu.h. All these are protected by a test skb->protocol == ETH_P_802_2. Which does not protect against this tun scenario. But the mac_len test added in this patch in llc_fixup_skb will indirectly protect those too. That is called from llc_rcv before any other LLC code. It is tempting to just add a blanket mac_len check in llc_rcv, but not sure whether that could break valid LLC paths that do not assume an Ethernet header. 802.2 LLC may be used on top of non-802.3 protocols in principle. The below referenced commit shows that used to, on top of Token Ring. At least one of the three eth_hdr uses goes back to before the start of git history. But the one that syzbot exercises is introduced in this commit. That commit is old enough (2008), that effectively all stable kernels should receive this. Fixes: f83f1768f833 ("[LLC]: skb allocation size for responses") Reported-by: syzbot+a8c7be6dee0de1b669cc@syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20231025234251.3796495-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7b3ba18703a63f6fd487183b9262b08e5632da1b ]

LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.

Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).

    BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
    BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
    llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
    llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
    llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
    __netif_receive_skb_one_core net/core/dev.c:5523 [inline]
    __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637
    netif_receive_skb_internal net/core/dev.c:5723 [inline]
    netif_receive_skb+0x58/0x660 net/core/dev.c:5782
    tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
    tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002

Add a mac_len test before all three eth_hdr(skb) calls under net/llc.

There are further uses in include/net/llc_pdu.h. All these are
protected by a test skb->protocol == ETH_P_802_2. Which does not
protect against this tun scenario.

But the mac_len test added in this patch in llc_fixup_skb will
indirectly protect those too. That is called from llc_rcv before any
other LLC code.

It is tempting to just add a blanket mac_len check in llc_rcv, but
not sure whether that could break valid LLC paths that do not assume
an Ethernet header. 802.2 LLC may be used on top of non-802.3
protocols in principle. The below referenced commit shows that used
to, on top of Token Ring.

At least one of the three eth_hdr uses goes back to before the start
of git history. But the one that syzbot exercises is introduced in
this commit. That commit is old enough (2008), that effectively all
stable kernels should receive this.

Fixes: f83f1768f833 ("[LLC]: skb allocation size for responses")
Reported-by: syzbot+a8c7be6dee0de1b669cc@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231025234251.3796495-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv6: avoid atomic fragment on GSO packets 2023-11-20T09:27:33+00:00 Yan Zhai yan@cloudflare.com 2023-10-24T14:26:40+00:00 a81fd15757f54cd36e0b906e0e0d7a206bb95c7e [ Upstream commit 03d6c848bfb406e9ef6d9846d759e97beaeea113 ] When the ipv6 stack output a GSO packet, if its gso_size is larger than dst MTU, then all segments would be fragmented. However, it is possible for a GSO packet to have a trailing segment with smaller actual size than both gso_size as well as the MTU, which leads to an "atomic fragment". Atomic fragments are considered harmful in RFC-8021. An Existing report from APNIC also shows that atomic fragments are more likely to be dropped even it is equivalent to a no-op [1]. Add an extra check in the GSO slow output path. For each segment from the original over-sized packet, if it fits with the path MTU, then avoid generating an atomic fragment. Link: https://www.potaroo.net/presentations/2022-03-01-ipv6-frag.pdf [1] Fixes: b210de4f8c97 ("net: ipv6: Validate GSO SKB before finish IPv6 processing") Reported-by: David Wragg <dwragg@cloudflare.com> Signed-off-by: Yan Zhai <yan@cloudflare.com> Link: https://lore.kernel.org/r/90912e3503a242dca0bc36958b11ed03a2696e5e.1698156966.git.yan@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 03d6c848bfb406e9ef6d9846d759e97beaeea113 ]

When the ipv6 stack output a GSO packet, if its gso_size is larger than
dst MTU, then all segments would be fragmented. However, it is possible
for a GSO packet to have a trailing segment with smaller actual size
than both gso_size as well as the MTU, which leads to an "atomic
fragment". Atomic fragments are considered harmful in RFC-8021. An
Existing report from APNIC also shows that atomic fragments are more
likely to be dropped even it is equivalent to a no-op [1].

Add an extra check in the GSO slow output path. For each segment from
the original over-sized packet, if it fits with the path MTU, then avoid
generating an atomic fragment.

Link: https://www.potaroo.net/presentations/2022-03-01-ipv6-frag.pdf [1]
Fixes: b210de4f8c97 ("net: ipv6: Validate GSO SKB before finish IPv6 processing")
Reported-by: David Wragg <dwragg@cloudflare.com>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Link: https://lore.kernel.org/r/90912e3503a242dca0bc36958b11ed03a2696e5e.1698156966.git.yan@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp_metrics: do not create an entry from tcp_init_metrics() 2023-11-20T09:27:33+00:00 Eric Dumazet edumazet@google.com 2023-09-22T22:03:55+00:00 80f402e3333d50f90e04fe9cb647c3547c9c7c0d [ Upstream commit a135798e6e200ecb2f864cecca6d257ba278370c ] tcp_init_metrics() only wants to get metrics if they were previously stored in the cache. Creating an entry is adding useless costs, especially when tcp_no_metrics_save is set. Fixes: 51c5d0c4b169 ("tcp: Maintain dynamic metrics in local cache.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a135798e6e200ecb2f864cecca6d257ba278370c ]

tcp_init_metrics() only wants to get metrics if they were
previously stored in the cache. Creating an entry is adding
useless costs, especially when tcp_no_metrics_save is set.

Fixes: 51c5d0c4b169 ("tcp: Maintain dynamic metrics in local cache.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>