1. Feb 23, 2024
    • Florian Westphal's avatar
      net: ip_tunnel: prevent perpetual headroom growth · 5ae1e992
      Florian Westphal authored
      
      
      syzkaller triggered following kasan splat:
      BUG: KASAN: use-after-free in __skb_flow_dissect+0x19d1/0x7a50 net/core/flow_dissector.c:1170
      Read of size 1 at addr ffff88812fb4000e by task syz-executor183/5191
      [..]
       kasan_report+0xda/0x110 mm/kasan/report.c:588
       __skb_flow_dissect+0x19d1/0x7a50 net/core/flow_dissector.c:1170
       skb_flow_dissect_flow_keys include/linux/skbuff.h:1514 [inline]
       ___skb_get_hash net/core/flow_dissector.c:1791 [inline]
       __skb_get_hash+0xc7/0x540 net/core/flow_dissector.c:1856
       skb_get_hash include/linux/skbuff.h:1556 [inline]
       ip_tunnel_xmit+0x1855/0x33c0 net/ipv4/ip_tunnel.c:748
       ipip_tunnel_xmit+0x3cc/0x4e0 net/ipv4/ipip.c:308
       __netdev_start_xmit include/linux/netdevice.h:4940 [inline]
       netdev_start_xmit include/linux/netdevice.h:4954 [inline]
       xmit_one net/core/dev.c:3548 [inline]
       dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3564
       __dev_queue_xmit+0x7c1/0x3d60 net/core/dev.c:4349
       dev_queue_xmit include/linux/netdevice.h:3134 [inline]
       neigh_connected_output+0x42c/0x5d0 net/core/neighbour.c:1592
       ...
       ip_finish_output2+0x833/0x2550 net/ipv4/ip_output.c:235
       ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:323
       ..
       iptunnel_xmit+0x5b4/0x9b0 net/ipv4/ip_tunnel_core.c:82
       ip_tunnel_xmit+0x1dbc/0x33c0 net/ipv4/ip_tunnel.c:831
       ipgre_xmit+0x4a1/0x980 net/ipv4/ip_gre.c:665
       __netdev_start_xmit include/linux/netdevice.h:4940 [inline]
       netdev_start_xmit include/linux/netdevice.h:4954 [inline]
       xmit_one net/core/dev.c:3548 [inline]
       dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3564
       ...
      
      The splat occurs because skb->data points past skb->head allocated area.
      This is because neigh layer does:
        __skb_pull(skb, skb_network_offset(skb));
      
      ... but skb_network_offset() returns a negative offset and __skb_pull()
      arg is unsigned.  IOW, we skb->data gets "adjusted" by a huge value.
      
      The negative value is returned because skb->head and skb->data distance is
      more than 64k and skb->network_header (u16) has wrapped around.
      
      The bug is in the ip_tunnel infrastructure, which can cause
      dev->needed_headroom to increment ad infinitum.
      
      The syzkaller reproducer consists of packets getting routed via a gre
      tunnel, and route of gre encapsulated packets pointing at another (ipip)
      tunnel.  The ipip encapsulation finds gre0 as next output device.
      
      This results in the following pattern:
      
      1). First packet is to be sent out via gre0.
      Route lookup found an output device, ipip0.
      
      2).
      ip_tunnel_xmit for gre0 bumps gre0->needed_headroom based on the future
      output device, rt.dev->needed_headroom (ipip0).
      
      3).
      ip output / start_xmit moves skb on to ipip0. which runs the same
      code path again (xmit recursion).
      
      4).
      Routing step for the post-gre0-encap packet finds gre0 as output device
      to use for ipip0 encapsulated packet.
      
      tunl0->needed_headroom is then incremented based on the (already bumped)
      gre0 device headroom.
      
      This repeats for every future packet:
      
      gre0->needed_headroom gets inflated because previous packets' ipip0 step
      incremented rt->dev (gre0) headroom, and ipip0 incremented because gre0
      needed_headroom was increased.
      
      For each subsequent packet, gre/ipip0->needed_headroom grows until
      post-expand-head reallocations result in a skb->head/data distance of
      more than 64k.
      
      Once that happens, skb->network_header (u16) wraps around when
      pskb_expand_head tries to make sure that skb_network_offset() is unchanged
      after the headroom expansion/reallocation.
      
      After this skb_network_offset(skb) returns a different (and negative)
      result post headroom expansion.
      
      The next trip to neigh layer (or anything else that would __skb_pull the
      network header) makes skb->data point to a memory location outside
      skb->head area.
      
      v2: Cap the needed_headroom update to an arbitarily chosen upperlimit to
      prevent perpetual increase instead of dropping the headroom increment
      completely.
      
      Reported-and-tested-by: default avatar <syzbot+bfde3bef047a81b8fde6@syzkaller.appspotmail.com>
      Closes: https://groups.google.com/g/syzkaller-bugs/c/fL9G6GtWskY/m/VKk_PR5FBAAJ
      Fixes: 243aad83
      
       ("ip_gre: include route header_len in max_headroom calculation")
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Reviewed-by: default avatarSimon Horman <horms@kernel.org>
      Link: https://lore.kernel.org/r/20240220135606.4939-1-fw@strlen.de
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      5ae1e992
    • Andre Werner's avatar
      net: smsc95xx: add support for SYS TEC USB-SPEmodule1 · 45532b21
      Andre Werner authored
      
      
      This patch adds support for the SYS TEC USB-SPEmodule1 10Base-T1L
      ethernet device to the existing smsc95xx driver by adding the new
      USB VID/PID pair.
      
      Signed-off-by: default avatarAndre Werner <andre.werner@systec-electronic.com>
      Link: https://lore.kernel.org/r/20240219053413.4732-1-andre.werner@systec-electronic.com
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      45532b21
    • Florian Westphal's avatar
      netlink: add nla be16/32 types to minlen array · 9a0d1885
      Florian Westphal authored
      
      
      BUG: KMSAN: uninit-value in nla_validate_range_unsigned lib/nlattr.c:222 [inline]
      BUG: KMSAN: uninit-value in nla_validate_int_range lib/nlattr.c:336 [inline]
      BUG: KMSAN: uninit-value in validate_nla lib/nlattr.c:575 [inline]
      BUG: KMSAN: uninit-value in __nla_validate_parse+0x2e20/0x45c0 lib/nlattr.c:631
       nla_validate_range_unsigned lib/nlattr.c:222 [inline]
       nla_validate_int_range lib/nlattr.c:336 [inline]
       validate_nla lib/nlattr.c:575 [inline]
      ...
      
      The message in question matches this policy:
      
       [NFTA_TARGET_REV]       = NLA_POLICY_MAX(NLA_BE32, 255),
      
      but because NLA_BE32 size in minlen array is 0, the validation
      code will read past the malformed (too small) attribute.
      
      Note: Other attributes, e.g. BITFIELD32, SINT, UINT.. are also missing:
      those likely should be added too.
      
      Reported-by: default avatar <syzbot+3f497b07aa3baf2fb4d0@syzkaller.appspotmail.com>
      Reported-by: default avatarxingwei lee <xrivendell7@gmail.com>
      Closes: https://lore.kernel.org/all/CABOYnLzFYHSnvTyS6zGa-udNX55+izqkOt2sB9WDqUcEGW6n8w@mail.gmail.com/raw
      Fixes: ecaf75ff
      
       ("netlink: introduce bigendian integer types")
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Link: https://lore.kernel.org/r/20240221172740.5092-1-fw@strlen.de
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      9a0d1885
    • Ryosuke Yasuoka's avatar
      netlink: Fix kernel-infoleak-after-free in __skb_datagram_iter · 661779e1
      Ryosuke Yasuoka authored
      syzbot reported the following uninit-value access issue [1]:
      
      netlink_to_full_skb() creates a new `skb` and puts the `skb->data`
      passed as a 1st arg of netlink_to_full_skb() onto new `skb`. The data
      size is specified as `len` and passed to skb_put_data(). This `len`
      is based on `skb->end` that is not data offset but buffer offset. The
      `skb->end` contains data and tailroom. Since the tailroom is not
      initialized when the new `skb` created, KMSAN detects uninitialized
      memory area when copying the data.
      
      This patch resolved this issue by correct the len from `skb->end` to
      `skb->len`, which is the actual data offset.
      
      BUG: KMSAN: kernel-infoleak-after-free in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
      BUG: KMSAN: kernel-infoleak-after-free in copy_to_user_iter lib/iov_iter.c:24 [inline]
      BUG: KMSAN: kernel-infoleak-after-free in iterate_ubuf include/linux/iov_iter.h:29 [inline]
      BUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
      BUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance include/linux/iov_iter.h:271 [inline]
      BUG: KMSAN: kernel-infoleak-after-free in _copy_to_iter+0x364/0x2520 lib/iov_iter.c:186
       instrument_copy_to_user include/linux/instrumented.h:114 [inline]
       copy_to_user_iter lib/iov_iter.c:24 [inline]
       iterate_ubuf include/linux/iov_iter.h:29 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
       iterate_and_advance include/linux/iov_iter.h:271 [inline]
       _copy_to_iter+0x364/0x2520 lib/iov_iter.c:186
       copy_to_iter include/linux/uio.h:197 [inline]
       simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:532
       __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:420
       skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546
       skb_copy_datagram_msg include/linux/skbuff.h:3960 [inline]
       packet_recvmsg+0xd9c/0x2000 net/packet/af_packet.c:3482
       sock_recvmsg_nosec net/socket.c:1044 [inline]
       sock_recvmsg net/socket.c:1066 [inline]
       sock_read_iter+0x467/0x580 net/socket.c:1136
       call_read_iter include/linux/fs.h:2014 [inline]
       new_sync_read fs/read_write.c:389 [inline]
       vfs_read+0x8f6/0xe00 fs/read_write.c:470
       ksys_read+0x20f/0x4c0 fs/read_write.c:613
       __do_sys_read fs/read_write.c:623 [inline]
       __se_sys_read fs/read_write.c:621 [inline]
       __x64_sys_read+0x93/0xd0 fs/read_write.c:621
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b
      
      Uninit was stored to memory at:
       skb_put_data include/linux/skbuff.h:2622 [inline]
       netlink_to_full_skb net/netlink/af_netlink.c:181 [inline]
       __netlink_deliver_tap_skb net/netlink/af_netlink.c:298 [inline]
       __netlink_deliver_tap+0x5be/0xc90 net/netlink/af_netlink.c:325
       netlink_deliver_tap net/netlink/af_netlink.c:338 [inline]
       netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline]
       netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
       netlink_unicast+0x10f1/0x1250 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:745 [inline]
       ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
       ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
       __sys_sendmsg net/socket.c:2667 [inline]
       __do_sys_sendmsg net/socket.c:2676 [inline]
       __se_sys_sendmsg net/socket.c:2674 [inline]
       __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b
      
      Uninit was created at:
       free_pages_prepare mm/page_alloc.c:1087 [inline]
       free_unref_page_prepare+0xb0/0xa40 mm/page_alloc.c:2347
       free_unref_page_list+0xeb/0x1100 mm/page_alloc.c:2533
       release_pages+0x23d3/0x2410 mm/swap.c:1042
       free_pages_and_swap_cache+0xd9/0xf0 mm/swap_state.c:316
       tlb_batch_pages_flush mm/mmu_gather.c:98 [inline]
       tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
       tlb_flush_mmu+0x6f5/0x980 mm/mmu_gather.c:300
       tlb_finish_mmu+0x101/0x260 mm/mmu_gather.c:392
       exit_mmap+0x49e/0xd30 mm/mmap.c:3321
       __mmput+0x13f/0x530 kernel/fork.c:1349
       mmput+0x8a/0xa0 kernel/fork.c:1371
       exit_mm+0x1b8/0x360 kernel/exit.c:567
       do_exit+0xd57/0x4080 kernel/exit.c:858
       do_group_exit+0x2fd/0x390 kernel/exit.c:1021
       __do_sys_exit_group kernel/exit.c:1032 [inline]
       __se_sys_exit_group kernel/exit.c:1030 [inline]
       __x64_sys_exit_group+0x3c/0x50 kernel/exit.c:1030
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b
      
      Bytes 3852-3903 of 3904 are uninitialized
      Memory access of size 3904 starts at ffff88812ea1e000
      Data copied to user address 0000000020003280
      
      CPU: 1 PID: 5043 Comm: syz-executor297 Not tainted 6.7.0-rc5-syzkaller-00047-g5bd7ef53 #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
      
      Fixes: 1853c949
      
       ("netlink, mmap: transform mmap skb into full skb on taps")
      Reported-and-tested-by: default avatar <syzbot+34ad5fab48f7bf510349@syzkaller.appspotmail.com>
      Closes: https://syzkaller.appspot.com/bug?extid=34ad5fab48f7bf510349
      
       [1]
      Signed-off-by: default avatarRyosuke Yasuoka <ryasuoka@redhat.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Link: https://lore.kernel.org/r/20240221074053.1794118-1-ryasuoka@redhat.com
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      661779e1
    • Linus Torvalds's avatar
      Merge tag 'net-6.8.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 6714ebb9
      Linus Torvalds authored
      Pull networking fixes from Paolo Abeni:
       "Including fixes from bpf and netfilter.
      
        Current release - regressions:
      
         - af_unix: fix another unix GC hangup
      
        Previous releases - regressions:
      
         - core: fix a possible AF_UNIX deadlock
      
         - bpf: fix NULL pointer dereference in sk_psock_verdict_data_ready()
      
         - netfilter: nft_flow_offload: release dst in case direct xmit path
           is used
      
         - bridge: switchdev: ensure MDB events are delivered exactly once
      
         - l2tp: pass correct message length to ip6_append_data
      
         - dccp/tcp: unhash sk from ehash for tb2 alloc failure after
           check_estalblished()
      
         - tls: fixes for record type handling with PEEK
      
         - devlink: fix possible use-after-free and memory leaks in
           devlink_init()
      
        Previous releases - always broken:
      
         - bpf: fix an oops when attempting to read the vsyscall page through
           bpf_probe_read_kernel
      
         - sched: act_mirred: use the backlog for ...
      6714ebb9
    • Linus Torvalds's avatar
      Merge tag 'trace-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace · efa80dcb
      Linus Torvalds authored
      Pull tracing fix from Steven Rostedt:
      
       - While working on the ring buffer I noticed that the counter used for
         knowing where the end of the data is on a sub-buffer was not a full
         "int" but just 20 bits. It was masked out to 0xfffff.
      
         With the new code that allows the user to change the size of the
         sub-buffer, it is theoretically possible to ask for a size bigger
         than 2^20. If that happens, unexpected results may occur as there's
         no code checking if the counter overflowed the 20 bits of the write
         mask. There are other checks to make sure events fit in the
         sub-buffer, but if the sub-buffer itself is too big, that is not
         checked.
      
         Add a check in the resize of the sub-buffer to make sure that it
         never goes beyond the size of the counter that holds how much data is
         on it.
      
      * tag 'trace-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
        ring-buffer: Do not let subbuf be bigger than write mask
      efa80dcb
  2. Feb 22, 2024
  3. Feb 21, 2024