1. 23 Feb, 2024 2 commits
    • 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: 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.deSigned-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: 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.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      661779e1
  2. 22 Feb, 2024 19 commits
  3. 21 Feb, 2024 19 commits