In the Linux kernel, the following vulnerability has been resolved:
rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The per-netns structure can be obtained from the table->data using
container_of(), then the 'net' one can be retrieved from the listen
socket (if available).
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: rto_min/max: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used.
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is
used.
In the Linux kernel, the following vulnerability has been resolved:
cgroup/cpuset: remove kernfs active break
A warning was found:
WARNING: CPU: 10 PID: 3486953 at fs/kernfs/file.c:828
CPU: 10 PID: 3486953 Comm: rmdir Kdump: loaded Tainted: G
RIP: 0010:kernfs_should_drain_open_files+0x1a1/0x1b0
RSP: 0018:ffff8881107ef9e0 EFLAGS: 00010202
RAX: 0000000080000002 RBX: ffff888154738c00 RCX: dffffc0000000000
RDX: 0000000000000007 RSI: 0000000000000004 RDI: ffff888154738c04
RBP: ffff888154738c04 R08: ffffffffaf27fa15 R09: ffffed102a8e7180
R10: ffff888154738c07 R11: 0000000000000000 R12: ffff888154738c08
R13: ffff888750f8c000 R14: ffff888750f8c0e8 R15: ffff888154738ca0
FS: 00007f84cd0be740(0000) GS:ffff8887ddc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f9fbe00c8 CR3: 0000000153eec001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_drain+0x15e/0x2f0
__kernfs_remove+0x165/0x300
kernfs_remove_by_name_ns+0x7b/0xc0
cgroup_rm_file+0x154/0x1c0
cgroup_addrm_files+0x1c2/0x1f0
css_clear_dir+0x77/0x110
kill_css+0x4c/0x1b0
cgroup_destroy_locked+0x194/0x380
cgroup_rmdir+0x2a/0x140
It can be explained by:
rmdir echo 1 > cpuset.cpus
kernfs_fop_write_iter // active=0
cgroup_rm_file
kernfs_remove_by_name_ns kernfs_get_active // active=1
__kernfs_remove // active=0x80000002
kernfs_drain cpuset_write_resmask
wait_event
//waiting (active == 0x80000001)
kernfs_break_active_protection
// active = 0x80000001
// continue
kernfs_unbreak_active_protection
// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
kernfs_put_active
This warning is caused by 'kernfs_break_active_protection' when it is
writing to cpuset.cpus, and the cgroup is removed concurrently.
The commit 3a5a6d0c2b03 ("cpuset: don't nest cgroup_mutex inside
get_online_cpus()") made cpuset_hotplug_workfn asynchronous, This change
involves calling flush_work(), which can create a multiple processes
circular locking dependency that involve cgroup_mutex, potentially leading
to a deadlock. To avoid deadlock. the commit 76bb5ab8f6e3 ("cpuset: break
kernfs active protection in cpuset_write_resmask()") added
'kernfs_break_active_protection' in the cpuset_write_resmask. This could
lead to this warning.
After the commit 2125c0034c5d ("cgroup/cpuset: Make cpuset hotplug
processing synchronous"), the cpuset_write_resmask no longer needs to
wait the hotplug to finish, which means that concurrent hotplug and cpuset
operations are no longer possible. Therefore, the deadlock doesn't exist
anymore and it does not have to 'break active protection' now. To fix this
warning, just remove kernfs_break_active_protection operation in the
'cpuset_write_resmask'.
In the Linux kernel, the following vulnerability has been resolved:
net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets
The blamed commit disabled hardware offoad of IPv6 packets with
extension headers on devices that advertise NETIF_F_IPV6_CSUM,
based on the definition of that feature in skbuff.h:
* * - %NETIF_F_IPV6_CSUM
* - Driver (device) is only able to checksum plain
* TCP or UDP packets over IPv6. These are specifically
* unencapsulated packets of the form IPv6|TCP or
* IPv6|UDP where the Next Header field in the IPv6
* header is either TCP or UDP. IPv6 extension headers
* are not supported with this feature. This feature
* cannot be set in features for a device with
* NETIF_F_HW_CSUM also set. This feature is being
* DEPRECATED (see below).
The change causes skb_warn_bad_offload to fire for BIG TCP
packets.
[ 496.310233] WARNING: CPU: 13 PID: 23472 at net/core/dev.c:3129 skb_warn_bad_offload+0xc4/0xe0
[ 496.310297] ? skb_warn_bad_offload+0xc4/0xe0
[ 496.310300] skb_checksum_help+0x129/0x1f0
[ 496.310303] skb_csum_hwoffload_help+0x150/0x1b0
[ 496.310306] validate_xmit_skb+0x159/0x270
[ 496.310309] validate_xmit_skb_list+0x41/0x70
[ 496.310312] sch_direct_xmit+0x5c/0x250
[ 496.310317] __qdisc_run+0x388/0x620
BIG TCP introduced an IPV6_TLV_JUMBO IPv6 extension header to
communicate packet length, as this is an IPv6 jumbogram. But, the
feature is only enabled on devices that support BIG TCP TSO. The
header is only present for PF_PACKET taps like tcpdump, and not
transmitted by physical devices.
For this specific case of extension headers that are not
transmitted, return to the situation before the blamed commit
and support hardware offload.
ipv6_has_hopopt_jumbo() tests not only whether this header is present,
but also that it is the only extension header before a terminal (L4)
header.
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: clear link ID from bitmap during link delete after clean up
Currently, during link deletion, the link ID is first removed from the
valid_links bitmap before performing any clean-up operations. However, some
functions require the link ID to remain in the valid_links bitmap. One
such example is cfg80211_cac_event(). The flow is -
nl80211_remove_link()
cfg80211_remove_link()
ieee80211_del_intf_link()
ieee80211_vif_set_links()
ieee80211_vif_update_links()
ieee80211_link_stop()
cfg80211_cac_event()
cfg80211_cac_event() requires link ID to be present but it is cleared
already in cfg80211_remove_link(). Ultimately, WARN_ON() is hit.
Therefore, clear the link ID from the bitmap only after completing the link
clean-up.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix mbss changed flags corruption on 32 bit systems
On 32-bit systems, the size of an unsigned long is 4 bytes,
while a u64 is 8 bytes. Therefore, when using
or_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE),
the code is incorrectly searching for a bit in a 32-bit
variable that is expected to be 64 bits in size,
leading to incorrect bit finding.
Solution: Ensure that the size of the bits variable is correctly
adjusted for each architecture.
Call Trace:
? show_regs+0x54/0x58
? __warn+0x6b/0xd4
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? report_bug+0x113/0x150
? exc_overflow+0x30/0x30
? handle_bug+0x27/0x44
? exc_invalid_op+0x18/0x50
? handle_exception+0xf6/0xf6
? exc_overflow+0x30/0x30
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? exc_overflow+0x30/0x30
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? ieee80211_mesh_work+0xff/0x260 [mac80211]
? cfg80211_wiphy_work+0x72/0x98 [cfg80211]
? process_one_work+0xf1/0x1fc
? worker_thread+0x2c0/0x3b4
? kthread+0xc7/0xf0
? mod_delayed_work_on+0x4c/0x4c
? kthread_complete_and_exit+0x14/0x14
? ret_from_fork+0x24/0x38
? kthread_complete_and_exit+0x14/0x14
? ret_from_fork_asm+0xf/0x14
? entry_INT80_32+0xf0/0xf0
[restore no-op path for no changes]
In the Linux kernel, the following vulnerability has been resolved:
drm: adv7511: Fix use-after-free in adv7533_attach_dsi()
The host_node pointer was assigned and freed in adv7533_parse_dt(), and
later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue
by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put()
in error path of probe() and also in the remove().
In the Linux kernel, the following vulnerability has been resolved:
workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work from !WQ_MEM_RECLAIM worker
After commit
746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")
amdgpu started seeing the following warning:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu]
...
[ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched]
...
[ ] Call Trace:
[ ] <TASK>
...
[ ] ? check_flush_dependency+0xf5/0x110
...
[ ] cancel_delayed_work_sync+0x6e/0x80
[ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu]
[ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu]
[ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu]
[ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched]
[ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu]
[ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched]
[ ] process_one_work+0x217/0x720
...
[ ] </TASK>
The intent of the verifcation done in check_flush_depedency is to ensure
forward progress during memory reclaim, by flagging cases when either a
memory reclaim process, or a memory reclaim work item is flushed from a
context not marked as memory reclaim safe.
This is correct when flushing, but when called from the
cancel(_delayed)_work_sync() paths it is a false positive because work is
either already running, or will not be running at all. Therefore
cancelling it is safe and we can relax the warning criteria by letting the
helper know of the calling context.
References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")