| Message ID | 3b3151922d3737d9c5a6c9fb7be1c10164e8a06f.1519739283.git.dcaratti@redhat.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] af_smc: fix NULL pointer dereference on sock_create_kern() error path | expand |
On 02/27/2018 02:49 PM, Davide Caratti wrote: > when sock_create_kern(..., a) returns an error, 'a' might not be a valid > pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and > and a->sk->sk_rcvbuf; not doing that caused the following crash: > > general protection fault: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410 > RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746 > RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020 > RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0 > FS: 0000000001afb880(0000) GS:ffff8801db200000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __sock_create+0x4d4/0x850 net/socket.c:1285 > sock_create net/socket.c:1325 [inline] > SYSC_socketpair net/socket.c:1409 [inline] > SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366 > do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x26/0x9b > RIP: 0033:0x4404b9 > RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b > RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031 > R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff > R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000 > Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48 > b8 > 00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02 > 00 > 0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00 > RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8 > > Fixes: cd6851f30386 smc: remote memory buffers (RMBs) > Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com > Signed-off-by: Davide Caratti <dcaratti@redhat.com> > --- > net/smc/af_smc.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index da1a5cdefd13..8cc97834d4f6 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -1406,8 +1406,10 @@ static int smc_create(struct net *net, struct socket *sock, int protocol, > smc->use_fallback = false; /* assume rdma capability first */ > rc = sock_create_kern(net, PF_INET, SOCK_STREAM, > IPPROTO_TCP, &smc->clcsock); > - if (rc) > + if (rc) { > sk_common_release(sk); > + goto out; > + } > smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE); > smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE); > Thanks Davide, I add your patch to our local repository; it will be part of my next patch set to be sent to Dave Miller. Regards, Ursula
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index da1a5cdefd13..8cc97834d4f6 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1406,8 +1406,10 @@ static int smc_create(struct net *net, struct socket *sock, int protocol, smc->use_fallback = false; /* assume rdma capability first */ rc = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &smc->clcsock); - if (rc) + if (rc) { sk_common_release(sk); + goto out; + } smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE); smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
when sock_create_kern(..., a) returns an error, 'a' might not be a valid pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and and a->sk->sk_rcvbuf; not doing that caused the following crash: general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746 RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020 RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0 FS: 0000000001afb880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sock_create+0x4d4/0x850 net/socket.c:1285 sock_create net/socket.c:1325 [inline] SYSC_socketpair net/socket.c:1409 [inline] SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x4404b9 RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031 R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000 Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00 RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8 Fixes: cd6851f30386 smc: remote memory buffers (RMBs) Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com Signed-off-by: Davide Caratti <dcaratti@redhat.com> --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)