linux/net/smc
Davide Caratti a5dcb73b96 net/smc: fix NULL pointer dereference on sock_create_kern() error path
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: cd6851f303 smc: remote memory buffers (RMBs)
Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-28 12:30:25 -05:00
..
af_smc.c net/smc: fix NULL pointer dereference on sock_create_kern() error path 2018-02-28 12:30:25 -05:00
Kconfig net/smc: remove Kconfig warning 2017-07-29 11:22:58 -07:00
Makefile smc: netlink interface for SMC sockets 2017-01-09 16:07:41 -05:00
smc_cdc.c net/smc: use a constant for control message length 2018-02-28 12:30:25 -05:00
smc_cdc.h net/smc: get rid of tx_pend waits in socket closing 2018-01-24 10:52:57 -05:00
smc_clc.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
smc_clc.h smc: support variable CLC proposal messages 2017-12-07 15:03:12 -05:00
smc_close.c net/smc: release clcsock from tcp_listen_worker 2018-01-26 10:41:56 -05:00
smc_close.h net/smc: replace sock_put worker by socket refcounting 2018-01-26 10:41:56 -05:00
smc_core.c net/smc: use link_id of server in confirm link reply 2018-02-28 12:30:25 -05:00
smc_core.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_diag.c net/smc: check for healthy link group resp. connections 2018-01-25 16:10:42 -05:00
smc_ib.c net/smc: handle device, port, and QP error events 2018-01-26 10:41:56 -05:00
smc_ib.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_llc.c net/smc: use link_id of server in confirm link reply 2018-02-28 12:30:25 -05:00
smc_llc.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_pnet.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_pnet.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_rx.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
smc_rx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_tx.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
smc_tx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smc_wr.c net/smc: check for healthy link group resp. connections 2018-01-25 16:10:42 -05:00
smc_wr.h net/smc: get rid of tx_pend waits in socket closing 2018-01-24 10:52:57 -05:00
smc.h net/smc: return booleans instead of integers 2018-01-26 10:41:56 -05:00