linux/net/rds
Eric Dumazet 6fa19f5637 rds: fix refcount bug in rds_sock_addref
syzbot was able to catch a bug in rds [1]

The issue here is that the socket might be found in a hash table
but that its refcount has already be set to 0 by another cpu.

We need to use refcount_inc_not_zero() to be safe here.

[1]

refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23129 Comm: syz-executor3 Not tainted 5.0.0-rc4+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x48 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Code: 1d 51 63 c8 06 31 ff 89 de e8 eb 1b f2 fd 84 db 75 dd e8 a2 1a f2 fd 48 c7 c7 60 9f 81 88 c6 05 31 63 c8 06 01 e8 af 65 bb fd <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49
RSP: 0018:ffff8880a0cbf1e8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90006113000
RDX: 000000000001047d RSI: ffffffff81685776 RDI: 0000000000000005
RBP: ffff8880a0cbf1f8 R08: ffff888097c9e100 R09: ffffed1015ce5021
R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: ffff8880723c20c0
R13: ffff8880723c24b0 R14: dffffc0000000000 R15: ffffed1014197e64
 sock_hold include/net/sock.h:647 [inline]
 rds_sock_addref+0x19/0x20 net/rds/af_rds.c:675
 rds_find_bound+0x97c/0x1080 net/rds/bind.c:82
 rds_recv_incoming+0x3be/0x1430 net/rds/recv.c:362
 rds_loop_xmit+0xf3/0x2a0 net/rds/loop.c:96
 rds_send_xmit+0x1355/0x2a10 net/rds/send.c:355
 rds_sendmsg+0x323c/0x44e0 net/rds/send.c:1368
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 __sys_sendto+0x387/0x5f0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto net/socket.c:1796 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458089
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc266df8c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458089
RDX: 0000000000000000 RSI: 00000000204b3fff RDI: 0000000000000005
RBP: 000000000073bf00 R08: 00000000202b4000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc266df96d4
R13: 00000000004c56e4 R14: 00000000004d94a8 R15: 00000000ffffffff

Fixes: cc4dfb7f70 ("rds: fix two RCU related problems")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Cc: rds-devel@oss.oracle.com
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-31 09:43:27 -08:00
..
af_rds.c rds: Remove IPv6 dependency 2018-08-01 09:32:35 -07:00
bind.c rds: fix refcount bug in rds_sock_addref 2019-01-31 09:43:27 -08:00
cong.c rds: Changing IP address internal representation to struct in6_addr 2018-07-23 21:17:44 -07:00
connection.c rds: Remove IPv6 dependency 2018-08-01 09:32:35 -07:00
ib_cm.c rds: Remove IPv6 dependency 2018-08-01 09:32:35 -07:00
ib_fmr.c net/rds/ib_fmr.c: use kmalloc_array_node() 2017-11-15 18:21:02 -08:00
ib_frmr.c Merge branch 'linus/master' into rdma.git for-next 2018-08-16 14:21:29 -06:00
ib_mr.h Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
ib_rdma.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
ib_recv.c Merge branch 'linus/master' into rdma.git for-next 2018-08-16 14:21:29 -06:00
ib_ring.c
ib_send.c rds: use DIV_ROUND_UP instead of ceil 2019-01-07 07:22:36 -08:00
ib_stats.c RDS: IB: add few useful cache stasts 2017-01-02 14:02:51 -08:00
ib_sysctl.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
ib.c RDMA: Start use ib_device_ops 2018-12-12 07:40:16 -07:00
ib.h rds: Fix build regression. 2018-09-23 12:25:15 -07:00
info.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
info.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig net/rds: RDS is not Radio Data System 2018-08-31 23:09:53 -07:00
loop.c rds: Changing IP address internal representation to struct in6_addr 2018-07-23 21:17:44 -07:00
loop.h rds: clean up loopback rds_connections on netns deletion 2018-06-27 10:11:03 +09:00
Makefile rds: remove trailing whitespace and blank lines 2018-07-24 14:10:42 -07:00
message.c rds: use DIV_ROUND_UP instead of ceil 2019-01-07 07:22:36 -08:00
page.c rds: remove dead code 2016-12-26 21:35:39 -05:00
rdma_transport.c rds: Remove IPv6 dependency 2018-08-01 09:32:35 -07:00
rdma_transport.h rds: Enable RDS IPv6 support 2018-07-23 21:17:44 -07:00
rdma.c net/rds: remove user triggered WARN_ON in rds_sendmsg 2018-12-19 10:27:58 -08:00
rds_single_path.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rds.h rds: use DIV_ROUND_UP instead of ceil 2019-01-07 07:22:36 -08:00
recv.c net: rds: use memset to optimize the recv 2018-09-17 08:19:51 -07:00
send.c rds: use DIV_ROUND_UP instead of ceil 2019-01-07 07:22:36 -08:00
stats.c net/rds: zero last byte for strncpy 2013-03-08 00:35:44 -05:00
sysctl.c net: rds: fix coding style issues 2016-06-18 21:34:09 -07:00
tcp_connect.c rds: Enable RDS IPv6 support 2018-07-23 21:17:44 -07:00
tcp_listen.c rds: Remove IPv6 dependency 2018-08-01 09:32:35 -07:00
tcp_recv.c rds: Changing IP address internal representation to struct in6_addr 2018-07-23 21:17:44 -07:00
tcp_send.c rds: Changing IP address internal representation to struct in6_addr 2018-07-23 21:17:44 -07:00
tcp_stats.c net: rds: fix const array syntax 2011-07-01 16:16:19 -07:00
tcp.c net: rds: remove unnecessary NULL check 2019-01-01 09:54:19 -08:00
tcp.h rds: Enable RDS IPv6 support 2018-07-23 21:17:44 -07:00
threads.c rds: Changing IP address internal representation to struct in6_addr 2018-07-23 21:17:44 -07:00
transport.c rds: remove trailing whitespace and blank lines 2018-07-24 14:10:42 -07:00