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