| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: fix client side handling of tls alerts
A security exploit was discovered in NFS over TLS in tls_alert_recv
due to its assumption that there is valid data in the msghdr's
iterator's kvec.
Instead, this patch proposes the rework how control messages are
setup and used by sock_recvmsg().
If no control message structure is setup, kTLS layer will read and
process TLS data record types. As soon as it encounters a TLS control
message, it would return an error. At that point, NFS can setup a kvec
backed control buffer and read in the control message such as a TLS
alert. Scott found that a msg iterator can advance the kvec pointer
as a part of the copy process thus we need to revert the iterator
before calling into the tls_alert_recv. |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: fix handling of server side tls alerts
Scott Mayhew discovered a security exploit in NFS over TLS in
tls_alert_recv() due to its assumption it can read data from
the msg iterator's kvec..
kTLS implementation splits TLS non-data record payload between
the control message buffer (which includes the type such as TLS
aler or TLS cipher change) and the rest of the payload (say TLS
alert's level/description) which goes into the msg payload buffer.
This patch proposes to rework how control messages are setup and
used by sock_recvmsg().
If no control message structure is setup, kTLS layer will read and
process TLS data record types. As soon as it encounters a TLS control
message, it would return an error. At that point, NFS can setup a
kvec backed msg buffer and read in the control message such as a
TLS alert. Msg iterator can advance the kvec pointer as a part of
the copy process thus we need to revert the iterator before calling
into the tls_alert_recv. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/sev: Evict cache lines during SNP memory validation
An SNP cache coherency vulnerability requires a cache line eviction
mitigation when validating memory after a page state change to private.
The specific mitigation is to touch the first and last byte of each 4K
page that is being validated. There is no need to perform the mitigation
when performing a page state change to shared and rescinding validation.
CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit
that, when set, indicates that the software mitigation for this
vulnerability is not needed.
Implement the mitigation and invoke it when validating memory (making it
private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP
guest is vulnerable. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: plug races between subflow fail and subflow creation
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.
The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.
The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.
The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Add down_write(trace_event_sem) when adding trace event
When a module is loaded, it adds trace events defined by the module. It
may also need to modify the modules trace printk formats to replace enum
names with their values.
If two modules are loaded at the same time, the adding of the event to the
ftrace_events list can corrupt the walking of the list in the code that is
modifying the printk format strings and crash the kernel.
The addition of the event should take the trace_event_sem for write while
it adds the new event.
Also add a lockdep_assert_held() on that semaphore in
__trace_add_event_dirs() as it iterates the list. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject %p% format string in bprintf-like helpers
static const char fmt[] = "%p%";
bpf_trace_printk(fmt, sizeof(fmt));
The above BPF program isn't rejected and causes a kernel warning at
runtime:
Please remove unsupported %\x00 in format string
WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0
This happens because bpf_bprintf_prepare skips over the second %,
detected as punctuation, while processing %p. This patch fixes it by
not skipping over punctuation. %\x00 is then processed in the next
iteration and rejected. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix use-after-free in cifs_oplock_break
A race condition can occur in cifs_oplock_break() leading to a
use-after-free of the cinode structure when unmounting:
cifs_oplock_break()
_cifsFileInfo_put(cfile)
cifsFileInfo_put_final()
cifs_sb_deactive()
[last ref, start releasing sb]
kill_sb()
kill_anon_super()
generic_shutdown_super()
evict_inodes()
dispose_list()
evict()
destroy_inode()
call_rcu(&inode->i_rcu, i_callback)
spin_lock(&cinode->open_file_lock) <- OK
[later] i_callback()
cifs_free_inode()
kmem_cache_free(cinode)
spin_unlock(&cinode->open_file_lock) <- UAF
cifs_done_oplock_break(cinode) <- UAF
The issue occurs when umount has already released its reference to the
superblock. When _cifsFileInfo_put() calls cifs_sb_deactive(), this
releases the last reference, triggering the immediate cleanup of all
inodes under RCU. However, cifs_oplock_break() continues to access the
cinode after this point, resulting in use-after-free.
Fix this by holding an extra reference to the superblock during the
entire oplock break operation. This ensures that the superblock and
its inodes remain valid until the oplock break completes. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: add NULL check in eswitch lag check
The function ice_lag_is_switchdev_running() is being called from outside of
the LAG event handler code. This results in the lag->upper_netdev being
NULL sometimes. To avoid a NULL-pointer dereference, there needs to be a
check before it is dereferenced. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix oops due to non-existence of prealloc backlog struct
If an AF_RXRPC service socket is opened and bound, but calls are
preallocated, then rxrpc_alloc_incoming_call() will oops because the
rxrpc_backlog struct doesn't get allocated until the first preallocation is
made.
Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no
backlog struct. This will cause the incoming call to be aborted. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: prevent A-MSDU attacks in mesh networks
This patch is a mitigation to prevent the A-MSDU spoofing vulnerability
for mesh networks. The initial update to the IEEE 802.11 standard, in
response to the FragAttacks, missed this case (CVE-2025-27558). It can
be considered a variant of CVE-2020-24588 but for mesh networks.
This patch tries to detect if a standard MSDU was turned into an A-MSDU
by an adversary. This is done by parsing a received A-MSDU as a standard
MSDU, calculating the length of the Mesh Control header, and seeing if
the 6 bytes after this header equal the start of an rfc1042 header. If
equal, this is a strong indication of an ongoing attack attempt.
This defense was tested with mac80211_hwsim against a mesh network that
uses an empty Mesh Address Extension field, i.e., when four addresses
are used, and when using a 12-byte Mesh Address Extension field, i.e.,
when six addresses are used. Functionality of normal MSDUs and A-MSDUs
was also tested, and confirmed working, when using both an empty and
12-byte Mesh Address Extension field.
It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh
networks keep being detected and prevented.
Note that the vulnerability being patched, and the defense being
implemented, was also discussed in the following paper and in the
following IEEE 802.11 presentation:
https://papers.mathyvanhoef.com/wisec2025.pdf
https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-protection.docx |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/pf: Clear all LMTT pages on alloc
Our LMEM buffer objects are not cleared by default on alloc
and during VF provisioning we only setup LMTT PTEs for the
actually provisioned LMEM range. But beyond that valid range
we might leave some stale data that could either point to some
other VFs allocations or even to the PF pages.
Explicitly clear all new LMTT page to avoid the risk that a
malicious VF would try to exploit that gap.
While around add asserts to catch any undesired PTE overwrites
and low-level debug traces to track LMTT PT life-cycle.
(cherry picked from commit 3fae6918a3e27cce20ded2551f863fb05d4bef8d) |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mwifiex: discard erroneous disassoc frames on STA interface
When operating in concurrent STA/AP mode with host MLME enabled,
the firmware incorrectly sends disassociation frames to the STA
interface when clients disconnect from the AP interface.
This causes kernel warnings as the STA interface processes
disconnect events that don't apply to it:
[ 1303.240540] WARNING: CPU: 0 PID: 513 at net/wireless/mlme.c:141 cfg80211_process_disassoc+0x78/0xec [cfg80211]
[ 1303.250861] Modules linked in: 8021q garp stp mrp llc rfcomm bnep btnxpuart nls_iso8859_1 nls_cp437 onboard_us
[ 1303.327651] CPU: 0 UID: 0 PID: 513 Comm: kworker/u9:2 Not tainted 6.16.0-rc1+ #3 PREEMPT
[ 1303.335937] Hardware name: Toradex Verdin AM62 WB on Verdin Development Board (DT)
[ 1303.343588] Workqueue: MWIFIEX_RX_WORK_QUEUE mwifiex_rx_work_queue [mwifiex]
[ 1303.350856] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 1303.357904] pc : cfg80211_process_disassoc+0x78/0xec [cfg80211]
[ 1303.364065] lr : cfg80211_process_disassoc+0x70/0xec [cfg80211]
[ 1303.370221] sp : ffff800083053be0
[ 1303.373590] x29: ffff800083053be0 x28: 0000000000000000 x27: 0000000000000000
[ 1303.380855] x26: 0000000000000000 x25: 00000000ffffffff x24: ffff000002c5b8ae
[ 1303.388120] x23: ffff000002c5b884 x22: 0000000000000001 x21: 0000000000000008
[ 1303.395382] x20: ffff000002c5b8ae x19: ffff0000064dd408 x18: 0000000000000006
[ 1303.402646] x17: 3a36333a61623a30 x16: 32206d6f72662063 x15: ffff800080bfe048
[ 1303.409910] x14: ffff000003625300 x13: 0000000000000001 x12: 0000000000000000
[ 1303.417173] x11: 0000000000000002 x10: ffff000003958600 x9 : ffff000003625300
[ 1303.424434] x8 : ffff00003fd9ef40 x7 : ffff0000039fc280 x6 : 0000000000000002
[ 1303.431695] x5 : ffff0000038976d4 x4 : 0000000000000000 x3 : 0000000000003186
[ 1303.438956] x2 : 000000004836ba20 x1 : 0000000000006986 x0 : 00000000d00479de
[ 1303.446221] Call trace:
[ 1303.448722] cfg80211_process_disassoc+0x78/0xec [cfg80211] (P)
[ 1303.454894] cfg80211_rx_mlme_mgmt+0x64/0xf8 [cfg80211]
[ 1303.460362] mwifiex_process_mgmt_packet+0x1ec/0x460 [mwifiex]
[ 1303.466380] mwifiex_process_sta_rx_packet+0x1bc/0x2a0 [mwifiex]
[ 1303.472573] mwifiex_handle_rx_packet+0xb4/0x13c [mwifiex]
[ 1303.478243] mwifiex_rx_work_queue+0x158/0x198 [mwifiex]
[ 1303.483734] process_one_work+0x14c/0x28c
[ 1303.487845] worker_thread+0x2cc/0x3d4
[ 1303.491680] kthread+0x12c/0x208
[ 1303.495014] ret_from_fork+0x10/0x20
Add validation in the STA receive path to verify that disassoc/deauth
frames originate from the connected AP. Frames that fail this check
are discarded early, preventing them from reaching the MLME layer and
triggering WARN_ON().
This filtering logic is similar with that used in the
ieee80211_rx_mgmt_disassoc() function in mac80211, which drops
disassoc frames that don't match the current BSSID
(!ether_addr_equal(mgmt->bssid, sdata->vif.cfg.ap_addr)), ensuring
only relevant frames are processed.
Tested on:
- 8997 with FW 16.68.1.p197 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix oob access in cgroup local storage
Lonial reported that an out-of-bounds access in cgroup local storage
can be crafted via tail calls. Given two programs each utilizing a
cgroup local storage with a different value size, and one program
doing a tail call into the other. The verifier will validate each of
the indivial programs just fine. However, in the runtime context
the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the
BPF program as well as any cgroup local storage flavor the program
uses. Helpers such as bpf_get_local_storage() pick this up from the
runtime context:
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
storage = ctx->prog_item->cgroup_storage[stype];
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
else
ptr = this_cpu_ptr(storage->percpu_buf);
For the second program which was called from the originally attached
one, this means bpf_get_local_storage() will pick up the former
program's map, not its own. With mismatching sizes, this can result
in an unintended out-of-bounds access.
To fix this issue, we need to extend bpf_map_owner with an array of
storage_cookie[] to match on i) the exact maps from the original
program if the second program was using bpf_get_local_storage(), or
ii) allow the tail call combination if the second program was not
using any of the cgroup local storage maps. |
| In the Linux kernel, the following vulnerability has been resolved:
clone_private_mnt(): make sure that caller has CAP_SYS_ADMIN in the right userns
What we want is to verify there is that clone won't expose something
hidden by a mount we wouldn't be able to undo. "Wouldn't be able to undo"
may be a result of MNT_LOCKED on a child, but it may also come from
lacking admin rights in the userns of the namespace mount belongs to.
clone_private_mnt() checks the former, but not the latter.
There's a number of rather confusing CAP_SYS_ADMIN checks in various
userns during the mount, especially with the new mount API; they serve
different purposes and in case of clone_private_mnt() they usually,
but not always end up covering the missing check mentioned above. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: make fallback action and fallback decision atomic
Syzkaller reported the following splat:
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 __mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 check_fully_established net/mptcp/options.c:982 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Modules linked in:
CPU: 1 UID: 0 PID: 7704 Comm: syz.3.1419 Not tainted 6.16.0-rc3-gbd5ce2324dba #20 PREEMPT(voluntary)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
RIP: 0010:mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
RIP: 0010:check_fully_established net/mptcp/options.c:982 [inline]
RIP: 0010:mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Code: 24 18 e8 bb 2a 00 fd e9 1b df ff ff e8 b1 21 0f 00 e8 ec 5f c4 fc 44 0f b7 ac 24 b0 00 00 00 e9 54 f1 ff ff e8 d9 5f c4 fc 90 <0f> 0b 90 e9 b8 f4 ff ff e8 8b 2a 00 fd e9 8d e6 ff ff e8 81 2a 00
RSP: 0018:ffff8880a3f08448 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880180a8000 RCX: ffffffff84afcf45
RDX: ffff888090223700 RSI: ffffffff84afdaa7 RDI: 0000000000000001
RBP: ffff888017955780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880180a8910 R14: ffff8880a3e9d058 R15: 0000000000000000
FS: 00005555791b8500(0000) GS:ffff88811c495000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2800b7 CR3: 0000000058e44000 CR4: 0000000000350ef0
Call Trace:
<IRQ>
tcp_reset+0x26f/0x2b0 net/ipv4/tcp_input.c:4432
tcp_validate_incoming+0x1057/0x1b60 net/ipv4/tcp_input.c:5975
tcp_rcv_established+0x5b5/0x21f0 net/ipv4/tcp_input.c:6166
tcp_v4_do_rcv+0x5dc/0xa70 net/ipv4/tcp_ipv4.c:1925
tcp_v4_rcv+0x3473/0x44a0 net/ipv4/tcp_ipv4.c:2363
ip_protocol_deliver_rcu+0xba/0x480 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2f1/0x500 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_local_deliver+0x1be/0x560 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:469 [inline]
ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_rcv+0x514/0x810 net/ipv4/ip_input.c:567
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5975
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6088
process_backlog+0x301/0x1360 net/core/dev.c:6440
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7453
napi_poll net/core/dev.c:7517 [inline]
net_rx_action+0xb44/0x1010 net/core/dev.c:7644
handle_softirqs+0x1d0/0x770 kernel/softirq.c:579
do_softirq+0x3f/0x90 kernel/softirq.c:480
</IRQ>
<TASK>
__local_bh_enable_ip+0xed/0x110 kernel/softirq.c:407
local_bh_enable include/linux/bottom_half.h:33 [inline]
inet_csk_listen_stop+0x2c5/0x1070 net/ipv4/inet_connection_sock.c:1524
mptcp_check_listen_stop.part.0+0x1cc/0x220 net/mptcp/protocol.c:2985
mptcp_check_listen_stop net/mptcp/mib.h:118 [inline]
__mptcp_close+0x9b9/0xbd0 net/mptcp/protocol.c:3000
mptcp_close+0x2f/0x140 net/mptcp/protocol.c:3066
inet_release+0xed/0x200 net/ipv4/af_inet.c:435
inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x402/0xb70 fs/file_table.c:465
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xd4
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: Fix initialization of data for instructions that write to subdevice
Some Comedi subdevice instruction handlers are known to access
instruction data elements beyond the first `insn->n` elements in some
cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions
allocate at least `MIN_SAMPLES` (16) data elements to deal with this,
but they do not initialize all of that. For Comedi instruction codes
that write to the subdevice, the first `insn->n` data elements are
copied from user-space, but the remaining elements are left
uninitialized. That could be a problem if the subdevice instruction
handler reads the uninitialized data. Ensure that the first
`MIN_SAMPLES` elements are initialized before calling these instruction
handlers, filling the uncopied elements with 0. For
`do_insnlist_ioctl()`, the same data buffer elements are used for
handling a list of instructions, so ensure the first `MIN_SAMPLES`
elements are initialized for each instruction that writes to the
subdevice. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
A crash in conntrack was reported while trying to unlink the conntrack
entry from the hash bucket list:
[exception RIP: __nf_ct_delete_from_lists+172]
[..]
#7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack]
#8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack]
#9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack]
[..]
The nf_conn struct is marked as allocated from slab but appears to be in
a partially initialised state:
ct hlist pointer is garbage; looks like the ct hash value
(hence crash).
ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected
ct->timeout is 30000 (=30s), which is unexpected.
Everything else looks like normal udp conntrack entry. If we ignore
ct->status and pretend its 0, the entry matches those that are newly
allocated but not yet inserted into the hash:
- ct hlist pointers are overloaded and store/cache the raw tuple hash
- ct->timeout matches the relative time expected for a new udp flow
rather than the absolute 'jiffies' value.
If it were not for the presence of IPS_CONFIRMED,
__nf_conntrack_find_get() would have skipped the entry.
Theory is that we did hit following race:
cpu x cpu y cpu z
found entry E found entry E
E is expired <preemption>
nf_ct_delete()
return E to rcu slab
init_conntrack
E is re-inited,
ct->status set to 0
reply tuplehash hnnode.pprev
stores hash value.
cpu y found E right before it was deleted on cpu x.
E is now re-inited on cpu z. cpu y was preempted before
checking for expiry and/or confirm bit.
->refcnt set to 1
E now owned by skb
->timeout set to 30000
If cpu y were to resume now, it would observe E as
expired but would skip E due to missing CONFIRMED bit.
nf_conntrack_confirm gets called
sets: ct->status |= CONFIRMED
This is wrong: E is not yet added
to hashtable.
cpu y resumes, it observes E as expired but CONFIRMED:
<resumes>
nf_ct_expired()
-> yes (ct->timeout is 30s)
confirmed bit set.
cpu y will try to delete E from the hashtable:
nf_ct_delete() -> set DYING bit
__nf_ct_delete_from_lists
Even this scenario doesn't guarantee a crash:
cpu z still holds the table bucket lock(s) so y blocks:
wait for spinlock held by z
CONFIRMED is set but there is no
guarantee ct will be added to hash:
"chaintoolong" or "clash resolution"
logic both skip the insert step.
reply hnnode.pprev still stores the
hash value.
unlocks spinlock
return NF_DROP
<unblocks, then
crashes on hlist_nulls_del_rcu pprev>
In case CPU z does insert the entry into the hashtable, cpu y will unlink
E again right away but no crash occurs.
Without 'cpu y' race, 'garbage' hlist is of no consequence:
ct refcnt remains at 1, eventually skb will be free'd and E gets
destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy.
To resolve this, move the IPS_CONFIRMED assignment after the table
insertion but before the unlock.
Pablo points out that the confirm-bit-store could be reordered to happen
before hlist add resp. the timeout fixup, so switch to set_bit and
before_atomic memory barrier to prevent this.
It doesn't matter if other CPUs can observe a newly inserted entry right
before the CONFIRMED bit was set:
Such event cannot be distinguished from above "E is the old incarnation"
case: the entry will be skipped.
Also change nf_ct_should_gc() to first check the confirmed bit.
The gc sequence is:
1. Check if entry has expired, if not skip to next entry
2. Obtain a reference to the expired entry.
3. Call nf_ct_should_gc() to double-check step 1.
nf_ct_should_gc() is thus called only for entries that already failed an
expiry check. After this patch, once the confirmed bit check pas
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime
Assuming the "rx-vlan-filter" feature is enabled on a net device, the
8021q module will automatically add or remove VLAN 0 when the net device
is put administratively up or down, respectively. There are a couple of
problems with the above scheme.
The first problem is a memory leak that can happen if the "rx-vlan-filter"
feature is disabled while the device is running:
# ip link add bond1 up type bond mode 0
# ethtool -K bond1 rx-vlan-filter off
# ip link del dev bond1
When the device is put administratively down the "rx-vlan-filter"
feature is disabled, so the 8021q module will not remove VLAN 0 and the
memory will be leaked [1].
Another problem that can happen is that the kernel can automatically
delete VLAN 0 when the device is put administratively down despite not
adding it when the device was put administratively up since during that
time the "rx-vlan-filter" feature was disabled. null-ptr-unref or
bug_on[2] will be triggered by unregister_vlan_dev() for refcount
imbalance if toggling filtering during runtime:
$ ip link add bond0 type bond mode 0
$ ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
$ ethtool -K bond0 rx-vlan-filter off
$ ifconfig bond0 up
$ ethtool -K bond0 rx-vlan-filter on
$ ifconfig bond0 down
$ ip link del vlan0
Root cause is as below:
step1: add vlan0 for real_dev, such as bond, team.
register_vlan_dev
vlan_vid_add(real_dev,htons(ETH_P_8021Q),0) //refcnt=1
step2: disable vlan filter feature and enable real_dev
step3: change filter from 0 to 1
vlan_device_event
vlan_filter_push_vids
ndo_vlan_rx_add_vid //No refcnt added to real_dev vlan0
step4: real_dev down
vlan_device_event
vlan_vid_del(dev, htons(ETH_P_8021Q), 0); //refcnt=0
vlan_info_rcu_free //free vlan0
step5: delete vlan0
unregister_vlan_dev
BUG_ON(!vlan_info); //vlan_info is null
Fix both problems by noting in the VLAN info whether VLAN 0 was
automatically added upon NETDEV_UP and based on that decide whether it
should be deleted upon NETDEV_DOWN, regardless of the state of the
"rx-vlan-filter" feature.
[1]
unreferenced object 0xffff8880068e3100 (size 256):
comm "ip", pid 384, jiffies 4296130254
hex dump (first 32 bytes):
00 20 30 0d 80 88 ff ff 00 00 00 00 00 00 00 00 . 0.............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 81ce31fa):
__kmalloc_cache_noprof+0x2b5/0x340
vlan_vid_add+0x434/0x940
vlan_device_event.cold+0x75/0xa8
notifier_call_chain+0xca/0x150
__dev_notify_flags+0xe3/0x250
rtnl_configure_link+0x193/0x260
rtnl_newlink_create+0x383/0x8e0
__rtnl_newlink+0x22c/0xa40
rtnl_newlink+0x627/0xb00
rtnetlink_rcv_msg+0x6fb/0xb70
netlink_rcv_skb+0x11f/0x350
netlink_unicast+0x426/0x710
netlink_sendmsg+0x75a/0xc20
__sock_sendmsg+0xc1/0x150
____sys_sendmsg+0x5aa/0x7b0
___sys_sendmsg+0xfc/0x180
[2]
kernel BUG at net/8021q/vlan.c:99!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 382 Comm: ip Not tainted 6.16.0-rc3 #61 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:unregister_vlan_dev (net/8021q/vlan.c:99 (discriminator 1))
RSP: 0018:ffff88810badf310 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88810da84000 RCX: ffffffffb47ceb9a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88810e8b43c8
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff6cefe80
R10: ffffffffb677f407 R11: ffff88810badf3c0 R12: ffff88810e8b4000
R13: 0000000000000000 R14: ffff88810642a5c0 R15: 000000000000017e
FS: 00007f1ff68c20c0(0000) GS:ffff888163a24000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ff5dad240 CR3: 0000000107e56000 CR4: 00000000000006f0
Call Trace:
<TASK
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
perf: Revert to requiring CAP_SYS_ADMIN for uprobes
Jann reports that uprobes can be used destructively when used in the
middle of an instruction. The kernel only verifies there is a valid
instruction at the requested offset, but due to variable instruction
length cannot determine if this is an instruction as seen by the
intended execution stream.
Additionally, Mark Rutland notes that on architectures that mix data
in the text segment (like arm64), a similar things can be done if the
data word is 'mistaken' for an instruction.
As such, require CAP_SYS_ADMIN for uprobes. |
| In the Linux kernel, the following vulnerability has been resolved:
atm: clip: Fix potential null-ptr-deref in to_atmarpd().
atmarpd is protected by RTNL since commit f3a0592b37b8 ("[ATM]: clip
causes unregister hang").
However, it is not enough because to_atmarpd() is called without RTNL,
especially clip_neigh_solicit() / neigh_ops->solicit() is unsleepable.
Also, there is no RTNL dependency around atmarpd.
Let's use a private mutex and RCU to protect access to atmarpd in
to_atmarpd(). |
