linux/include
Xin Long b563e9bbab sctp: avoid running the sctp state machine recursively
[ Upstream commit fbd019737d ]

Ying triggered a call trace when doing an asconf testing:

  BUG: scheduling while atomic: swapper/12/0/0x10000100
  Call Trace:
   <IRQ>  [<ffffffffa4375904>] dump_stack+0x19/0x1b
   [<ffffffffa436fcaf>] __schedule_bug+0x64/0x72
   [<ffffffffa437b93a>] __schedule+0x9ba/0xa00
   [<ffffffffa3cd5326>] __cond_resched+0x26/0x30
   [<ffffffffa437bc4a>] _cond_resched+0x3a/0x50
   [<ffffffffa3e22be8>] kmem_cache_alloc_node+0x38/0x200
   [<ffffffffa423512d>] __alloc_skb+0x5d/0x2d0
   [<ffffffffc0995320>] sctp_packet_transmit+0x610/0xa20 [sctp]
   [<ffffffffc098510e>] sctp_outq_flush+0x2ce/0xc00 [sctp]
   [<ffffffffc098646c>] sctp_outq_uncork+0x1c/0x20 [sctp]
   [<ffffffffc0977338>] sctp_cmd_interpreter.isra.22+0xc8/0x1460 [sctp]
   [<ffffffffc0976ad1>] sctp_do_sm+0xe1/0x350 [sctp]
   [<ffffffffc099443d>] sctp_primitive_ASCONF+0x3d/0x50 [sctp]
   [<ffffffffc0977384>] sctp_cmd_interpreter.isra.22+0x114/0x1460 [sctp]
   [<ffffffffc0976ad1>] sctp_do_sm+0xe1/0x350 [sctp]
   [<ffffffffc097b3a4>] sctp_assoc_bh_rcv+0xf4/0x1b0 [sctp]
   [<ffffffffc09840f1>] sctp_inq_push+0x51/0x70 [sctp]
   [<ffffffffc099732b>] sctp_rcv+0xa8b/0xbd0 [sctp]

As it shows, the first sctp_do_sm() running under atomic context (NET_RX
softirq) invoked sctp_primitive_ASCONF() that uses GFP_KERNEL flag later,
and this flag is supposed to be used in non-atomic context only. Besides,
sctp_do_sm() was called recursively, which is not expected.

Vlad tried to fix this recursive call in Commit c078669340 ("sctp: Fix
oops when sending queued ASCONF chunks") by introducing a new command
SCTP_CMD_SEND_NEXT_ASCONF. But it didn't work as this command is still
used in the first sctp_do_sm() call, and sctp_primitive_ASCONF() will
be called in this command again.

To avoid calling sctp_do_sm() recursively, we send the next queued ASCONF
not by sctp_primitive_ASCONF(), but by sctp_sf_do_prm_asconf() in the 1st
sctp_do_sm() directly.

Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-05 14:42:39 +02:00
..
acpi ACPICA: Update version to 20180810 2018-08-14 23:49:13 +02:00
asm-generic x86/unwind/orc: Fix ORC unwind table alignment 2019-03-23 20:10:10 +01:00
clocksource
crypto crypto: speck - remove Speck 2018-11-13 11:08:46 -08:00
drm drm: disable uncached DMA optimization for ARM and arm64 2019-03-13 14:02:40 -07:00
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys keys: Fix dependency loop between construction record and auth key 2019-03-23 20:09:48 +01:00
kvm KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock 2019-03-23 20:09:42 +01:00
linux ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK 2019-05-04 09:20:22 +02:00
math-emu
media media: cec: keep track of outstanding transmits 2019-01-09 17:38:46 +01:00
memory
misc
net sctp: avoid running the sctp state machine recursively 2019-05-05 14:42:39 +02:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
ras
rdma IB/rxe: Revise the ib_wr_opcode enum 2018-11-13 11:08:43 -08:00
scsi scsi: fcoe: make use of fip_mode enum complete 2019-04-05 22:33:04 +02:00
soc soc: fsl: qbman: add APIs to retrieve the probing status 2018-09-27 15:43:35 -05:00
sound ALSA: compress: Fix stop handling on compressed capture streams 2019-02-12 19:47:23 +01:00
target scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough 2019-01-26 09:32:38 +01:00
trace rxrpc: Fix client call connect/disconnect race 2019-04-20 09:16:05 +02:00
uapi netfilter: xt_cgroup: shrink size of v2 path 2019-04-20 09:16:00 +02:00
video udlfb: handle unplug properly 2019-02-27 10:09:03 +01:00
xen Revert "xen/balloon: Mark unallocated host memory as UNUSABLE" 2018-12-17 09:24:39 +01:00