1. 08 Jul, 2022 1 commit
  2. 07 Jul, 2022 1 commit
    • Eric Dumazet's avatar
      bpf: Make sure mac_header was set before using it · 0326195f
      Eric Dumazet authored
      Classic BPF has a way to load bytes starting from the mac header.
      
      Some skbs do not have a mac header, and skb_mac_header()
      in this case is returning a pointer that 65535 bytes after
      skb->head.
      
      Existing range check in bpf_internal_load_pointer_neg_helper()
      was properly kicking and no illegal access was happening.
      
      New sanity check in skb_mac_header() is firing, so we need
      to avoid it.
      
      WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 skb_mac_header include/linux/skbuff.h:2785 [inline]
      WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74
      Modules linked in:
      CPU: 1 PID: 28990 Comm: syz-executor.0 Not tainted 5.19.0-rc4-syzkaller-00865-g4874fb94 #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
      RIP: 0010:skb_mac_header include/linux/skbuff.h:2785 [inline]
      RIP: 0010:bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74
      Code: ff ff 45 31 f6 e9 5a ff ff ff e8 aa 27 40 00 e9 3b ff ff ff e8 90 27 40 00 e9 df fe ff ff e8 86 27 40 00 eb 9e e8 2f 2c f3 ff <0f> 0b eb b1 e8 96 27 40 00 e9 79 fe ff ff 90 41 57 41 56 41 55 41
      RSP: 0018:ffffc9000309f668 EFLAGS: 00010216
      RAX: 0000000000000118 RBX: ffffffffffeff00c RCX: ffffc9000e417000
      RDX: 0000000000040000 RSI: ffffffff81873f21 RDI: 0000000000000003
      RBP: ffff8880842878c0 R08: 0000000000000003 R09: 000000000000ffff
      R10: 000000000000ffff R11: 0000000000000001 R12: 0000000000000004
      R13: ffff88803ac56c00 R14: 000000000000ffff R15: dffffc0000000000
      FS: 00007f5c88a16700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
      CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007fdaa9f6c058 CR3: 000000003a82c000 CR4: 00000000003506e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
      <TASK>
      ____bpf_skb_load_helper_32 net/core/filter.c:276 [inline]
      bpf_skb_load_helper_32+0x191/0x220 net/core/filter.c:264
      
      Fixes: f9aefd6b ("net: warn if mac header was not set")
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Link: https://lore.kernel.org/bpf/20220707123900.945305-1-edumazet@google.com
      0326195f
  3. 06 Jul, 2022 13 commits
  4. 05 Jul, 2022 7 commits
  5. 04 Jul, 2022 18 commits