linux-stable.git/net/core/devlink.c, branch v5.15.78

devlink: Fix use-after-free after a failed reload

2022-08-25T09:40:06+00:00

commit 6b4db2e528f650c7fb712961aac36455468d5902 upstream.

After a failed devlink reload, devlink parameters are still registered,
which means user space can set and get their values. In the case of the
mlxsw "acl_region_rehash_interval" parameter, these operations will
trigger a use-after-free [1].

Fix this by rejecting set and get operations while in the failed state.
Return the "-EOPNOTSUPP" error code which does not abort the parameters
dump, but instead causes it to skip over the problematic parameter.

Another possible fix is to perform these checks in the mlxsw parameter
callbacks, but other drivers might be affected by the same problem and I
am not aware of scenarios where these stricter checks will cause a
regression.

[1]
mlxsw_spectrum3 0000:00:10.0: Port 125: Failed to register netdev
mlxsw_spectrum3 0000:00:10.0: Failed to create ports

==================================================================
BUG: KASAN: use-after-free in mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
Read of size 4 at addr ffff8880099dcfd8 by task kworker/u4:4/777

CPU: 1 PID: 777 Comm: kworker/u4:4 Not tainted 5.19.0-rc7-custom-126601-gfe26f28c586d #1
Hardware name: QEMU MSN4700, BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x92/0xbd lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:313 [inline]
 print_report.cold+0x5e/0x5cf mm/kasan/report.c:429
 kasan_report+0xb9/0xf0 mm/kasan/report.c:491
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
 mlxsw_sp_acl_region_rehash_intrvl_get+0x49/0x60 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c:1106
 mlxsw_sp_params_acl_region_rehash_intrvl_get+0x33/0x80 drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3854
 devlink_param_get net/core/devlink.c:4981 [inline]
 devlink_nl_param_fill+0x238/0x12d0 net/core/devlink.c:5089
 devlink_param_notify+0xe5/0x230 net/core/devlink.c:5168
 devlink_ns_change_notify net/core/devlink.c:4417 [inline]
 devlink_ns_change_notify net/core/devlink.c:4396 [inline]
 devlink_reload+0x15f/0x700 net/core/devlink.c:4507
 devlink_pernet_pre_exit+0x112/0x1d0 net/core/devlink.c:12272
 ops_pre_exit_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x494/0xc00 net/core/net_namespace.c:582
 process_one_work+0x9fc/0x1710 kernel/workqueue.c:2289
 worker_thread+0x675/0x10b0 kernel/workqueue.c:2436
 kthread+0x30c/0x3d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 

The buggy address belongs to the physical page:
page:ffffea0000267700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99dc
flags: 0x100000000000000(node=0|zone=1)
raw: 0100000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880099dce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880099dcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff8880099dd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Fixes: 98bbf70c1c41 ("mlxsw: spectrum: add "acl_region_rehash_interval" devlink param")
Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

devlink: Remove misleading internal_flags from health reporter dump

2022-01-27T10:05:39+00:00

commit e9538f8270db24d272659e15841854c7ea11119e upstream.

DEVLINK_CMD_HEALTH_REPORTER_DUMP_GET command doesn't have .doit callback
and has no use in internal_flags at all. Remove this misleading assignment.

Fixes: e44ef4e4516c ("devlink: Hang reporter's dump method on a dumpit cb")
Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

devlink: fix netns refcount leak in devlink_nl_cmd_reload()

2021-12-14T09:57:10+00:00

commit 4dbb0dad8e63fcd0b5a117c2861d2abe7ff5f186 upstream.

While preparing my patch series adding netns refcount tracking,
I spotted bugs in devlink_nl_cmd_reload()

Some error paths forgot to release a refcount on a netns.

To fix this, we can reduce the scope of get_net()/put_net()
section around the call to devlink_reload().

Fixes: ccdf07219da6 ("devlink: Add reload action option to devlink reload command")
Fixes: dc64cc7c6310 ("devlink: Add devlink reload limit option")
Signed-off-by: Eric Dumazet 
Cc: Moshe Shemesh 
Cc: Jacob Keller 
Cc: Jiri Pirko 
Reviewed-by: Leon Romanovsky 
Link: https://lore.kernel.org/r/20211205192822.1741045-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

devlink: Clear whole devlink_flash_notify struct

2021-08-14T12:59:10+00:00

The { 0 } doesn't clear all fields in the struct, but tells to the
compiler to set all fields to zero and doesn't touch any sub-fields
if they exists.

The {} is an empty initialiser that instructs to fully initialize whole
struct including sub-fields, which is error-prone for future
devlink_flash_notify extensions.

Fixes: 6700acc5f1fe ("devlink: collect flash notify params into a struct")
Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Use xarray to store devlink instances

2021-08-14T12:59:10+00:00

We can use xarray instead of linearly organized linked lists for the
devlink instances. This will let us revise the locking scheme in favour
of internal xarray locking that protects database.

Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Count struct devlink consumers

2021-08-14T12:59:10+00:00

The struct devlink itself is protected by internal lock and doesn't
need global lock during operation. That global lock is used to protect
addition/removal new devlink instances from the global list in use by
all devlink consumers in the system.

The future conversion of linked list to be xarray will allow us to
actually delete that lock, but first we need to count all struct devlink
users.

The reference counting provides us a way to ensure that no new user
space commands success to grab devlink instance which is going to be
destroyed makes it is safe to access it without lock.

Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Remove check of always valid devlink pointer

2021-08-14T12:59:10+00:00

Devlink objects are accessible only after they were registered and
have valid devlink_*->devlink pointers.

Remove that check and simplify respective fill functions as an outcome
of such change.

Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Simplify devlink_pernet_pre_exit call

2021-08-14T12:59:10+00:00

The devlink_pernet_pre_exit() will be called if net namespace exits.

That routine is relevant for devlink instances that were assigned to
that namespaces first. This assignment is possible only with the following
command: "devlink reload DEV netns ...", which already checks reload support.

Signed-off-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Add APIs to publish, unpublish individual parameter

2021-08-11T13:34:21+00:00

Enable drivers to publish/unpublish individual parameter.

Signed-off-by: Parav Pandit 
Reviewed-by: Jiri Pirko 
Reviewed-by: Leon Romanovsky 
Signed-off-by: David S. Miller

devlink: Add API to register and unregister single parameter

2021-08-11T13:34:21+00:00

Currently device configuration parameters can be registered as an array.
Due to this a constant array must be registered. A single driver
supporting multiple devices each with different device capabilities end
up registering all parameters even if it doesn't support it.

One possible workaround a driver can do is, it registers multiple single
entry arrays to overcome such limitation.

Better is to provide a API that enables driver to register/unregister a
single parameter. This also further helps in two ways.
(1) to reduce the memory of devlink_param_entry by avoiding in registering
parameters which are not supported by the device.
(2) avoid generating multiple parameter add, delete, publish, unpublish,
init value notifications for such unsupported parameters

Signed-off-by: Parav Pandit 
Reviewed-by: Jiri Pirko 
Reviewed-by: Leon Romanovsky 
Signed-off-by: David S. Miller