Linux kernel source tree
65161fb544
After the cited commit, dev_net(dev) is fetched before holding RTNL
and passed to __unregister_netdevice_notifier_net().
However, dev_net(dev) might be different after holding RTNL.
In the reported case [0], while removing a VF device, its netns was
being dismantled and the VF was moved to init_net.
So the following sequence is basically illegal when dev was fetched
without lookup:
net = dev_net(dev);
rtnl_net_lock(net);
Let's use a new helper rtnl_net_dev_lock() to fix the race.
It fetches dev_net_rcu(dev), bumps its net->passive, and checks if
dev_net_rcu(dev) is changed after rtnl_net_lock().
[0]:
BUG: KASAN: slab-use-after-free in notifier_call_chain (kernel/notifier.c:75 (discriminator 2))
Read of size 8 at addr ffff88810cefb4c8 by task test-bridge-lag/21127
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:123)
print_report (mm/kasan/report.c:379 mm/kasan/report.c:489)
kasan_report (mm/kasan/report.c:604)
notifier_call_chain (kernel/notifier.c:75 (discriminator 2))
call_netdevice_notifiers_info (net/core/dev.c:2011)
unregister_netdevice_many_notify (net/core/dev.c:11551)
unregister_netdevice_queue (net/core/dev.c:11487)
unregister_netdev (net/core/dev.c:11635)
mlx5e_remove (drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6552 drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6579) mlx5_core
auxiliary_bus_remove (drivers/base/auxiliary.c:230)
device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296)
bus_remove_device (./include/linux/kobject.h:193 drivers/base/base.h:73 drivers/base/bus.c:583)
device_del (drivers/base/power/power.h:142 drivers/base/core.c:3855)
mlx5_rescan_drivers_locked (./include/linux/auxiliary_bus.h:241 drivers/net/ethernet/mellanox/mlx5/core/dev.c:333 drivers/net/ethernet/mellanox/mlx5/core/dev.c:535 drivers/net/ethernet/mellanox/mlx5/core/dev.c:549) mlx5_core
mlx5_unregister_device (drivers/net/ethernet/mellanox/mlx5/core/dev.c:468) mlx5_core
mlx5_uninit_one (./include/linux/instrumented.h:68 ./include/asm-generic/bitops/instrumented-non-atomic.h:141 drivers/net/ethernet/mellanox/mlx5/core/main.c:1563) mlx5_core
remove_one (drivers/net/ethernet/mellanox/mlx5/core/main.c:965 drivers/net/ethernet/mellanox/mlx5/core/main.c:2019) mlx5_core
pci_device_remove (./include/linux/pm_runtime.h:129 drivers/pci/pci-driver.c:475)
device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296)
unbind_store (drivers/base/bus.c:245)
kernfs_fop_write_iter (fs/kernfs/file.c:338)
vfs_write (fs/read_write.c:587 (discriminator 1) fs/read_write.c:679 (discriminator 1))
ksys_write (fs/read_write.c:732)
do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
RIP: 0033:0x7f6a4d5018b7
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| 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 reStructuredText 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.