• D. Wythe's avatar
    net/smc: prevent UAF in inet_create() · 2fe5273f
    D. Wythe authored
    Following syzbot repro crashes the kernel:
    
    socketpair(0x2, 0x1, 0x100, &(0x7f0000000140)) (fail_nth: 13)
    
    Fix this by not calling sk_common_release() from smc_create_clcsk().
    
    Stack trace:
    socket: no more sockets
    ------------[ cut here ]------------
    refcount_t: underflow; use-after-free.
     WARNING: CPU: 1 PID: 5092 at lib/refcount.c:28
    refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
    Modules linked in:
    CPU: 1 PID: 5092 Comm: syz-executor424 Not tainted
    6.10.0-syzkaller-04483-g0be9ae54 #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
    Google 06/27/2024
     RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
    Code: 80 f3 1f 8c e8 e7 69 a8 fc 90 0f 0b 90 90 eb 99 e8 cb 4f e6 fc c6
    05 8a 8d e8 0a 01 90 48 c7 c7 e0 f3 1f 8c e8 c7 69 a8 fc 90 <0f> 0b 90
    90 e9 76 ff ff ff e8 a8 4f e6 fc c6 05 64 8d e8 0a 01 90
    RSP: 0018:ffffc900034cfcf0 EFLAGS: 00010246
    RAX: 3b9fcde1c862f700 RBX: ffff888022918b80 RCX: ffff88807b39bc00
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
    RBP: 0000000000000003 R08: ffffffff815878a2 R09: fffffbfff1c39d94
    R10: dffffc0000000000 R11: fffffbfff1c39d94 R12: 00000000ffffffe9
    R13: 1ffff11004523165 R14: ffff888022918b28 R15: ffff888022918b00
    FS:  00005555870e7380(0000) GS:ffff8880b9500000(0000)
    knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000020000140 CR3: 000000007582e000 CR4: 00000000003506f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     <TASK>
     inet_create+0xbaf/0xe70
      __sock_create+0x490/0x920 net/socket.c:1571
      sock_create net/socket.c:1622 [inline]
      __sys_socketpair+0x2ca/0x720 net/socket.c:1769
      __do_sys_socketpair net/socket.c:1822 [inline]
      __se_sys_socketpair net/socket.c:1819 [inline]
      __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
      do_syscall_x64 arch/x86/entry/common.c:52 [inline]
      do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    RIP: 0033:0x7fbcb9259669
    Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 00 00 90 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:00007fffe931c6d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
    RAX: ffffffffffffffda RBX: 00007fffe931c6f0 RCX: 00007fbcb9259669
    RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000002
    RBP: 0000000000000002 R08: 00007fffe931c476 R09: 00000000000000a0
    R10: 0000000020000140 R11: 0000000000000246 R12: 00007fffe931c6ec
    R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
     </TASK>
    
    Link: https://lore.kernel.org/r/20240723175809.537291-1-edumazet@google.com/
    Fixes: d25a92cc ("net/smc: Introduce IPPROTO_SMC")
    Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
    Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
    Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
    Reviewed-by: default avatarWenjia Zhang <wenjia@linux.ibm.com>
    Link: https://patch.msgid.link/1722224415-30999-1-git-send-email-alibuda@linux.alibaba.comSigned-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
    2fe5273f
af_smc.c 92.3 KB