linux/net/dccp
Eric Dumazet a8d7aa17bb dccp: fix tasklet usage
syzbot reported a crash in tasklet_action_common() caused by dccp.

dccp needs to make sure socket wont disappear before tasklet handler
has completed.

This patch takes a reference on the socket when arming the tasklet,
and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet()

kernel BUG at kernel/softirq.c:514!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515
RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246
dccp_close: ABORT with 65423 bytes unread
RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000
RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94
dccp_close: ABORT with 65423 bytes unread
R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000
R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tasklet_action+0x1d/0x20 kernel/softirq.c:533
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
dccp_close: ABORT with 65423 bytes unread
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8
RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8

Fixes: dc841e30ea ("dccp: Extend CCID packet dequeueing interface")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-03 15:14:57 -04:00
..
ccids dccp: fix tasklet usage 2018-05-03 15:14:57 -04:00
ackvec.c net: dccp: drop unneeded newline 2018-01-02 13:49:32 -05:00
ackvec.h net: dccp: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
ccid.c dccp: drop null test before destroy functions 2015-09-15 16:49:43 -07:00
ccid.h net: dccp: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
dccp.h net: annotate ->poll() instances 2017-11-27 16:20:04 -05:00
diag.c sock_diag: specify info_size per inet protocol 2015-06-15 19:49:22 -07:00
feat.c dccp: fix a memleak for dccp_feat_init err process 2017-07-27 00:01:05 -07:00
feat.h net: dccp: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
input.c net: dccp: mark expected switch fall-throughs 2017-10-16 21:15:21 +01:00
ipv4.c dccp: initialize ireq->ir_mark 2018-04-07 22:32:31 -04:00
ipv6.c dccp: initialize ireq->ir_mark 2018-04-07 22:32:31 -04:00
ipv6.h inet: includes a sock_common in request_sock 2013-10-10 00:08:07 -04:00
Kconfig net: dccp: Remove dccpprobe module 2018-01-02 14:27:30 -05:00
Makefile net: dccp: Remove dccpprobe module 2018-01-02 14:27:30 -05:00
minisocks.c tcp/dccp: avoid one atomic operation for timewait hashdance 2017-12-13 14:33:10 -05:00
options.c net: dccp: mark expected switch fall-throughs 2017-10-16 21:15:21 +01:00
output.c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
proto.c dccp: check sk for closed state in dccp_sendmsg() 2018-03-07 13:38:56 -05:00
qpolicy.c dccp qpolicy: Parameter checking of cmsg qpolicy parameters 2010-12-07 13:47:12 +01:00
sysctl.c dccp: make the request_retries minimum is 1 2014-05-14 15:34:16 -04:00
timer.c dccp: fix tasklet usage 2018-05-03 15:14:57 -04:00
trace.h net: dccp: Add DCCP sendmsg trace event 2018-01-02 14:27:30 -05:00