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Linux kernel source tree
This code reads two global variables without protection
of a lock. We need READ_ONCE()/WRITE_ONCE() pairs to
avoid load/store-tearing and better document the intent.
KCSAN reported :
BUG: KCSAN: data-race in icmp_global_allow / icmp_global_allow
read to 0xffffffff861a8014 of 4 bytes by task 11201 on cpu 0:
icmp_global_allow+0x36/0x1b0 net/ipv4/icmp.c:254
icmpv6_global_allow net/ipv6/icmp.c:184 [inline]
icmpv6_global_allow net/ipv6/icmp.c:179 [inline]
icmp6_send+0x493/0x1140 net/ipv6/icmp.c:514
icmpv6_send+0x71/0xb0 net/ipv6/ip6_icmp.c:43
ip6_link_failure+0x43/0x180 net/ipv6/route.c:2640
dst_link_failure include/net/dst.h:419 [inline]
vti_xmit net/ipv4/ip_vti.c:243 [inline]
vti_tunnel_xmit+0x27f/0xa50 net/ipv4/ip_vti.c:279
__netdev_start_xmit include/linux/netdevice.h:4420 [inline]
netdev_start_xmit include/linux/netdevice.h:4434 [inline]
xmit_one net/core/dev.c:3280 [inline]
dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3296
__dev_queue_xmit+0x14c9/0x1b60 net/core/dev.c:3873
dev_queue_xmit+0x21/0x30 net/core/dev.c:3906
neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a6/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
dst_output include/net/dst.h:436 [inline]
ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
write to 0xffffffff861a8014 of 4 bytes by task 11183 on cpu 1:
icmp_global_allow+0x174/0x1b0 net/ipv4/icmp.c:272
icmpv6_global_allow net/ipv6/icmp.c:184 [inline]
icmpv6_global_allow net/ipv6/icmp.c:179 [inline]
icmp6_send+0x493/0x1140 net/ipv6/icmp.c:514
icmpv6_send+0x71/0xb0 net/ipv6/ip6_icmp.c:43
ip6_link_failure+0x43/0x180 net/ipv6/route.c:2640
dst_link_failure include/net/dst.h:419 [inline]
vti_xmit net/ipv4/ip_vti.c:243 [inline]
vti_tunnel_xmit+0x27f/0xa50 net/ipv4/ip_vti.c:279
__netdev_start_xmit include/linux/netdevice.h:4420 [inline]
netdev_start_xmit include/linux/netdevice.h:4434 [inline]
xmit_one net/core/dev.c:3280 [inline]
dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3296
__dev_queue_xmit+0x14c9/0x1b60 net/core/dev.c:3873
dev_queue_xmit+0x21/0x30 net/core/dev.c:3906
neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a6/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11183 Comm: syz-executor.2 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.