Revision 4e43e64d0f1332fcc503babad4dc31aead7131ca authored by Eric Dumazet on 28 June 2022, 12:12:48 UTC, committed by Jakub Kicinski on 30 June 2022, 03:41:09 UTC
As reported by syzbot, we should not use rcu_dereference()
when rcu_read_lock() is not held.

WARNING: suspicious RCU usage
5.19.0-rc2-syzkaller #0 Not tainted

net/ipv6/addrconf.c:5175 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor326/3617:
 #0: ffffffff8d5848e8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xae/0xc20 net/netlink/af_netlink.c:2223

stack backtrace:
CPU: 0 PID: 3617 Comm: syz-executor326 Not tainted 5.19.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 in6_dump_addrs+0x12d1/0x1790 net/ipv6/addrconf.c:5175
 inet6_dump_addr+0x9c1/0xb50 net/ipv6/addrconf.c:5300
 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275
 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380
 netlink_dump_start include/linux/netlink.h:245 [inline]
 rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2492
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2546
 __sys_sendmsg net/socket.c:2575 [inline]
 __do_sys_sendmsg net/socket.c:2584 [inline]
 __se_sys_sendmsg net/socket.c:2582 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: 88e2ca308094 ("mld: convert ifmcaddr6 to RCU")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20220628121248.858695-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent fa152f6
Raw File
Makefile
# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the kernel character device drivers.
#

obj-y				+= mem.o random.o
obj-$(CONFIG_TTY_PRINTK)	+= ttyprintk.o
obj-y				+= misc.o
obj-$(CONFIG_ATARI_DSP56K)	+= dsp56k.o
obj-$(CONFIG_VIRTIO_CONSOLE)	+= virtio_console.o
obj-$(CONFIG_MSPEC)		+= mspec.o
obj-$(CONFIG_UV_MMTIMER)	+= uv_mmtimer.o
obj-$(CONFIG_IBM_BSR)		+= bsr.o

obj-$(CONFIG_PRINTER)		+= lp.o

obj-$(CONFIG_APM_EMULATION)	+= apm-emulation.o

obj-$(CONFIG_DTLK)		+= dtlk.o
obj-$(CONFIG_APPLICOM)		+= applicom.o
obj-$(CONFIG_SONYPI)		+= sonypi.o
obj-$(CONFIG_HPET)		+= hpet.o
obj-$(CONFIG_XILINX_HWICAP)	+= xilinx_hwicap/
obj-$(CONFIG_NVRAM)		+= nvram.o
obj-$(CONFIG_TOSHIBA)		+= toshiba.o
obj-$(CONFIG_DS1620)		+= ds1620.o
obj-$(CONFIG_HW_RANDOM)		+= hw_random/
obj-$(CONFIG_PPDEV)		+= ppdev.o
obj-$(CONFIG_NWBUTTON)		+= nwbutton.o
obj-$(CONFIG_NWFLASH)		+= nwflash.o
obj-$(CONFIG_SCx200_GPIO)	+= scx200_gpio.o
obj-$(CONFIG_PC8736x_GPIO)	+= pc8736x_gpio.o
obj-$(CONFIG_NSC_GPIO)		+= nsc_gpio.o
obj-$(CONFIG_GPIO_TB0219)	+= tb0219.o
obj-$(CONFIG_TELCLOCK)		+= tlclk.o

obj-$(CONFIG_MWAVE)		+= mwave/
obj-y				+= agp/
obj-$(CONFIG_PCMCIA)		+= pcmcia/

obj-$(CONFIG_HANGCHECK_TIMER)	+= hangcheck-timer.o
obj-$(CONFIG_TCG_TPM)		+= tpm/

obj-$(CONFIG_PS3_FLASH)		+= ps3flash.o

obj-$(CONFIG_XILLYBUS_CLASS)	+= xillybus/
obj-$(CONFIG_POWERNV_OP_PANEL)	+= powernv-op-panel.o
obj-$(CONFIG_ADI)		+= adi.o
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