| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/guc: Hold device ref until queue teardown completes
GuC exec queue destruction can run asynchronously. If the final device
put happens from a destroy worker, drmm cleanup can end up draining
the same workqueue and deadlock.
Hold a drm_device reference for the queue lifetime and drop it after
queue teardown completes. This keeps drmm cleanup from running while
async destroy work is still pending.
Move GuC destroy work to a module-lifetime Xe workqueue and flush it
on PCI remove so hot-unbind/rebind still waits for pending destroy work.
With queue-held device refs, guc_submit_sw_fini() cannot run with live
GuC IDs. Replace the fini wait with an assertion and remove the unused
fini_wq.
v2:
- Rebase
v3:
- Switch to queue-lifetime drm_dev_get()/drm_dev_put() model. (Matt)
- Queue async teardown on system_dfl_wq instead of xe->destroy_wq. (Matt)
- Drop separate deferred drm_dev_put worker.
- Remove stale drain_workqueue(xe->destroy_wq) from guc_submit_sw_fini().
v4:
- Replace the guc_submit_sw_fini() wait with an assertion and remove
the now-unused fini_wq. (sashiko)
v5:
- Move destroy work to a module-lifetime Xe workqueue instead of
system_dfl_wq. (Matt)
- Flush the module-lifetime destroy workqueue during PCI remove to
preserve the old device-remove wait semantics.
v6:
- Keep SVM pagemap destroy work on the per-device destroy_wq to avoid
letting it outlive the xe_device/drm_device. (Sashiko)
- Use WQ_MEM_RECLAIM for xe->destroy_wq because SVM pagemap destroy work
can be queued from the reclaim path.
v7:
- Drop the per-device xe->destroy_wq and use the module-level destroy WQ
for SVM pagemap destroy as well. (Matt)
- Rename xe_exec_queue_destroy_wq_*() helpers to xe_destroy_wq_*()
helpers because the WQ is no longer exec-queue specific. (Matt)
v8:
- Rebase.
v9:
- Keep SVM pagemap destroy work on the per-device WQ_MEM_RECLAIM
destroy_wq because it can be queued from reclaim and embeds
the dev_pagemap used by devres teardown. (Sashiko)
- Keep the module-level destroy WQ GuC-only and drop WQ_MEM_RECLAIM
from it.
- Update the module-WQ kdoc to document the GuC/SVM split.
v10:
- Keep xe->destroy_wq per-cpu while adding WQ_MEM_RECLAIM to fix the
workqueue allocation warning.
v11:
- Drop the SVM pagemap destroy comment as it was revision-specific.
(Thomas)
v12:
- Rebase.
(cherry picked from commit da1124abac689cc2b1d8995e5f0a816f8a122edb) |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: pin conn during async oplock break notification
smb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn
pointer in an async ksmbd_work and then queue that work on ksmbd-io. The
work only increments conn->r_count, which prevents teardown from passing
the pending-request wait after the increment, but it does not pin the
struct ksmbd_conn object.
If connection teardown races with an oplock break notification, the last
conn reference can be dropped before the queued worker finishes. The
worker then uses the freed conn in ksmbd_conn_write() and
ksmbd_conn_r_count_dec().
Take a real conn reference when publishing the conn pointer to the async
work item, and drop it after the notification work has decremented
r_count. Apply the same lifetime rule to lease break notification, which
uses the same work->conn pattern. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_tunnel_key: Defer dst_release to RCU callback
Fix a race-condition use-after-free in tunnel_key_release_params().
The function releases the metadata_dst of the old params synchronously
via dst_release() while deferring the params struct free with
kfree_rcu(). A concurrent tunnel_key_act() reader on the datapath may
still hold the old params pointer (under rcu_read_lock_bh) and proceed
to call dst_clone(¶ms->tcft_enc_metadata->dst) after the writer's
dst_release has already pushed the dst's rcuref to RCUREF_DEAD.
[email protected] produced a poc which i (and Victor) verified
that KASAN reports:
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112
BUG: KASAN: slab-use-after-free in atomic_sub_return_release include/linux/atomic/atomic-instrumented.h:326
BUG: KASAN: slab-use-after-free in __rcuref_put include/linux/rcuref.h:109
BUG: KASAN: slab-use-after-free in rcuref_put include/linux/rcuref.h:173
BUG: KASAN: slab-use-after-free in dst_release+0x5b/0x370 net/core/dst.c:168
Write of size 4 at addr ffff88806158de40 by task poc/9388
CPU: 0 UID: 0 PID: 9388 Comm: poc Tainted: G W 7.1.0-rc7 #7 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378
print_report+0x139/0x4ad mm/kasan/report.c:482
kasan_report+0xe4/0x1d0 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:186
kasan_check_range+0x125/0x200 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:112
atomic_sub_return_release include/linux/atomic/atomic-instrumented.h:326
__rcuref_put include/linux/rcuref.h:109
rcuref_put include/linux/rcuref.h:173
dst_release+0x5b/0x370 net/core/dst.c:168
refdst_drop include/net/dst.h:272
skb_dst_drop include/net/dst.h:284
skb_release_head_state+0x293/0x400 net/core/skbuff.c:1163
skb_release_all net/core/skbuff.c:1187
[..]
Allocated by task 9391:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398
__kasan_kmalloc+0x9a/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263
__do_kmalloc_node mm/slub.c:5296
__kmalloc_noprof+0x2f1/0x830 mm/slub.c:5308
kmalloc_noprof include/linux/slab.h:954
kzalloc_noprof include/linux/slab.h:1188
offload_action_alloc+0x2f/0x130 net/core/flow_offload.c:35
tcf_action_offload_add_ex+0x1ba/0x880 net/sched/act_api.c:258
tcf_action_offload_add net/sched/act_api.c:293
tcf_action_init+0x66e/0xa20 net/sched/act_api.c:1547
tcf_action_add+0xf6/0x5d0 net/sched/act_api.c:2101
[..]
Freed by task 9391:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253
__kasan_slab_free+0x6b/0x90 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235
slab_free_hook mm/slub.c:2689
slab_free mm/slub.c:6251
kfree+0x21f/0x6b0 mm/slub.c:6566
tcf_action_offload_add_ex+0x4ad/0x880 net/sched/act_api.c:284
tcf_action_offload_add net/sched/act_api.c:293
tcf_action_init+0x66e/0xa20 net/sched/act_api.c:1547
tcf_action_add+0xf6/0x5d0 net/sched/act_api.c:2101
The buggy address belongs to the object at ffff88806158de00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 64 bytes inside of
freed 256-byte region [ffff88806158de00, ffff88806158df00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88806158d600 pfn:0x6158c
head: order:1 mapcount:0 entire_map
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: fix auth_hmacs array size in struct sctp_cookie
The auth_hmacs array in struct sctp_cookie is supposed to store a complete
SCTP_AUTH_HMAC_ALGO parameter, which consists of a struct sctp_paramhdr
followed by N HMAC identifiers.
However, the array size was calculated using an extra 2 bytes instead of
sizeof(struct sctp_paramhdr), which is 4 bytes. When four HMAC identifiers
are configured, the HMAC-ALGO parameter stored in the endpoint is larger
than the auth_hmacs buffer in the cookie.
As a result, sctp_association_init() copies beyond the end of auth_hmacs
when initializing the association, corrupting the adjacent auth_chunks
field. This can lead to an invalid HMAC identifier being accepted and later
cause an out-of-bounds read in sctp_auth_get_hmac().
Fix the array size calculation by including the full SCTP parameter header
size. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: core: sysfs: add lock to bos_descriptors_read()
Add a lock to the function bos_descriptors_read().
This function accesses udev->bos, which could be simultaneously freed in
usb_reset_and_verify_device(), a function that is commonly called in
drivers all over the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: at76c50x-usb: avoid length underflow in at76_guess_freq()
at76_guess_freq() checks only that the received frame is at least a bare
802.11 header (24 bytes) before subtracting the fixed management-body
offset:
len -= el_off;
For both beacon and probe response frames, el_off is 36. If the frame is
shorter than el_off, subtracting it causes the calculated IE length to
wrap. The length is eventually passed to cfg80211_find_elem_match() as a
very large unsigned value, so the element walk runs beyond the RX skb.
This path is reached from at76_rx_tasklet() while scanning. If the device
delivers a truncated beacon or probe response, the oversized IE length
causes an out-of-bounds read during scanning.
Skip the IE lookup if the frame does not reach the variable elements,
before subtracting el_off. |
| In the Linux kernel, the following vulnerability has been resolved:
firewire: net: Fix fragmented datagram reassembly
fwnet_frag_new() keeps a sorted list of received fragments for a partial
datagram. When a new fragment is adjacent to an existing fragment, the
code checks whether the new fragment also closes the gap to the next or
previous list entry.
Those neighbor lookups currently assume that the current fragment always
has a real next or previous fragment. At a list edge, the next or
previous entry is the list head, not a struct fwnet_fragment_info.
The gap checks also compare against the old edge of the current fragment
instead of the edge after adding the new fragment. As a result, a
fragment that bridges two existing ranges may leave two adjacent ranges
unmerged, so fwnet_pd_is_complete() can miss a complete datagram.
Check for the list head before looking up the neighboring fragment, and
compare the neighbor against the new fragment's far edge when deciding
whether to merge all three ranges.
This issue was found by a static analysis checker and confirmed by
manual source review. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath6kl: fix OOB read from firmware IE lengths in connect event
The firmware-controlled beacon_ie_len, assoc_req_len, and assoc_resp_len
fields in ath6kl_wmi_connect_event_rx() are not validated against the
buffer length. Their sum (up to 765) can exceed the actual WMI event
data, causing out-of-bounds reads during IE parsing and state corruption
of wmi->is_wmm_enabled.
Add a check that the total IE length fits within the buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: tas2781: bound firmware description string parsing
The TAS2781 firmware parser reads several variable-length description
strings with strlen() before checking that the string terminator is
present inside the firmware blob. A malformed firmware image without a
NUL terminator can therefore make the parser walk past the end of the
firmware buffer before the later size checks run.
Add a small bounded string-length helper and use it for all description
fields that are parsed from the firmware buffer. Keep the existing size
checks for the fixed bytes that follow each string. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: validate DFS referral PathConsumed
parse_dfs_referrals() validates that the response contains the fixed
referral entry array and, on for-next, the per-referral string offsets.
However, the response also contains a PathConsumed value that is later
used for DFS path parsing.
If a malformed response provides a PathConsumed value larger than the
search name, later DFS parsing can advance beyond the end of the path.
Validate PathConsumed against the search name length before storing it in
the parsed referral. |
| In the Linux kernel, the following vulnerability has been resolved:
net/packet: avoid fanout hook re-registration after unregister
packet_set_ring() temporarily detaches a socket from packet delivery while
reconfiguring its ring. It records the previous running state, clears
po->num, unregisters the protocol hook when needed, drops po->bind_lock,
and later restores po->num and re-registers the hook from the saved
was_running value.
That unlocked window can race with NETDEV_UNREGISTER. The notifier can
observe the socket as not running, skip __unregister_prot_hook(), and
invalidate the per-socket binding by setting po->ifindex to -1 and clearing
po->prot_hook.dev. A one-member fanout group can still retain its shared
fanout hook device pointer. When packet_set_ring() resumes, re-registering
solely from the stale was_running state can re-add the fanout hook after
the device has been unregistered.
Treat po->ifindex == -1 as an invalidated binding after reacquiring
po->bind_lock. This is distinct from ifindex 0, the normal
unbound/wildcard state: ifindex -1 marks an existing device binding that
was invalidated when the device was unregistered. Restore po->num as
before, but do not re-register the hook if device unregister already
detached the socket. |
| In the Linux kernel, the following vulnerability has been resolved:
rds: drop incoming messages that cross network namespace boundaries
rds_find_bound() looks up the destination socket using a global
rhashtable keyed solely on (addr, port, scope_id). Network namespaces
are not part of the key, so a sender in netns A can deliver an incoming
message (inc) to a socket that lives in a different netns B.
When this happens, inc->i_conn points to an rds_connection whose c_net
is netns A, but the receiving rs lives in netns B. Once the child
process that created netns A exits, cleanup_net() calls
rds_loop_exit_net() -> rds_loop_kill_conns() -> rds_conn_destroy(),
freeing that connection. If the survivor socket in netns B still holds
the inc, any subsequent dereference of inc->i_conn is a use-after-free.
There are two dangerous sites in rds_clear_recv_queue():
1. inc->i_conn->c_lcong (offset 88 of freed rds_connection, size 200)
read via rds_recv_rcvbuf_delta() -- confirmed by KASAN.
2. inc->i_conn->c_trans->inc_free(inc) (function pointer at offset 80)
called via rds_inc_put() when the inc refcount reaches zero -- same
race window, potential call-through-freed-object primitive.
The bug is reachable from unprivileged user namespaces
(CLONE_NEWUSER + CLONE_NEWNET), available since Linux 3.8.
Fix this by rejecting the delivery in rds_recv_incoming() when the
socket returned by rds_find_bound() belongs to a different network
namespace than the connection that carried the message. Use the
existing rds_conn_net() / sock_net() helpers and net_eq() for the
comparison. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Wait for completion instead of returning early in iommu_completion_wait()
need_sync is a per-IOMMU flag shared by all domains and devices behind
that IOMMU. It is set whenever a command is queued with sync == true and
cleared when a completion-wait (CWAIT) command is queued. However, a
cleared need_sync only means that a covering CWAIT has been queued, not
that all previously queued commands have actually completed in hardware.
iommu_completion_wait() read need_sync locklessly and returned early
when it was false. This breaks the "block until all previously queued
commands have completed" contract in a multi-CPU scenario:
CPU2: queue inv-B => need_sync = true
CPU1: queue CWAIT(N); need_sync = false; then wait_on_sem(N)
CPU2: read need_sync == false => return 0 (no wait!)
CPU2 returns without waiting for any sequence number even though its
inv-B may not have completed yet (CWAIT(N), queued after inv-B, has not
been signaled). CPU2 then proceeds to, for example, free page-table
pages while the IOMMU can still walk stale translations, opening a
use-after-free window. This is a logical race in the meaning of the
flag, not a memory-visibility issue, so barriers alone do not help.
Fix it without losing the optimization of avoiding redundant CWAIT
commands: take iommu->lock before testing need_sync, and when it is
false do not return early but wait for the last allocated sequence
number (cmd_sem_val). Since need_sync == false implies no sync command
was queued after the last CWAIT, that CWAIT is FIFO-ordered after every
not-yet-completed command, so waiting for its sequence number guarantees
all prior commands (possibly queued by another CPU) have completed. The
common path with pending work is unchanged and no extra hardware command
is issued. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: serialize udp bearer replicast list updates
tipc_udp_rcast_add() and cleanup_bearer() both update ub->rcast.list with
list_add_rcu() / list_del_rcu(), but nothing serializes them. The add runs
from the encap receive softirq (via tipc_udp_rcast_disc()) without
rtnl_lock(), so it can race the cleanup delete and corrupt the list:
list_del corruption. prev->next should be ffff8880298d7ab8,
but was ffff88802449ad38. (prev=ffff888027e3ec98)
kernel BUG at lib/list_debug.c:62!
RIP: __list_del_entry_valid_or_report+0x17a/0x200
Workqueue: events cleanup_bearer
Call Trace:
cleanup_bearer (net/tipc/udp_media.c:811)
process_one_work (kernel/workqueue.c:3302)
worker_thread (kernel/workqueue.c:3466)
The bearer can be enabled from an unprivileged user namespace, as the
TIPCv2 generic-netlink ops carry no GENL_ADMIN_PERM.
Add a spinlock to struct udp_bearer and take it around the list_add_rcu()
in tipc_udp_rcast_add() and the list_del_rcu() loop in cleanup_bearer() so
the two writers can no longer corrupt the list.
Reject a duplicate peer under the same lock before allocating, and remove
tipc_udp_is_known_peer(). The old lockless pre-check in
tipc_udp_rcast_disc() was racy: two softirqs discovering the same peer
could both find it absent and add it twice.
cleanup_bearer() runs from a workqueue after tipc_udp_disable() clears the
bearer's up bit, so an encap softirq can still reach tipc_udp_rcast_add()
and add a peer after cleanup_bearer() has already emptied the list, leaking
that entry when the bearer is freed. Mark the bearer disabled under
rcast_lock once the list is emptied and refuse further additions. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid
sctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the
capacity limit for ep->auth_chunk_list, allowing it to hold up to
20 chunk entries (param_hdr.length up to 24). However, the copy
destination asoc->c.auth_chunks in struct sctp_cookie is only
SCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16
chunks are added, sctp_association_init() memcpy overflows the
destination by up to 4 bytes.
Fix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching
the destination capacity. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: validate stream count in sctp_process_strreset_inreq()
When processing a RESET_IN_REQUEST from a peer,
sctp_process_strreset_inreq() derives the stream count from the
parameter length but does not check whether the resulting
RESET_OUT_REQUEST would exceed SCTP_MAX_CHUNK_LEN.
The OUT request header (sctp_strreset_outreq, 16 bytes) is 8 bytes
larger than the IN request header (sctp_strreset_inreq, 8 bytes).
Generally, the IP payload is bounded to 65535 bytes, so the stream
list cannot be large enough to trigger the overflow. However, on
interfaces with MTU > 65535 (e.g., loopback with IPv6 jumbograms), a
stream list that fits within the incoming IN parameter can cause a
__u16 overflow in sctp_make_strreset_req() when computing the OUT
request size, leading to an undersized skb allocation and a kernel
BUG:
net/core/skbuff.c:207 skb_panic
net/core/skbuff.c:2625 skb_put
net/sctp/sm_make_chunk.c:1535 sctp_addto_chunk
net/sctp/sm_make_chunk.c:3695 sctp_make_strreset_req
net/sctp/stream.c:655 sctp_process_strreset_inreq
The local setsockopt path validates the generated reset request size.
However, for an incoming-only reset, it accounts for the smaller IN
request even though the peer must generate an OUT request with the same
stream list. Such a request cannot be completed successfully by the
peer.
Reject peer IN requests whose corresponding OUT request would exceed
SCTP_MAX_CHUNK_LEN. Also tighten the local check so it does not send an
IN request that would require an oversized OUT request from the peer. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: auth: verify auth requirement when auth_chunk is NULL
sctp_auth_chunk_verify() returns true unconditionally when
chunk->auth_chunk is NULL, silently skipping authentication.
This is incorrect when:
1. skb_clone() failed in the BH receive path, leaving auth_chunk
NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new
connections, so the early sctp_auth_recv_cid() check cannot
catch this.
2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never
called and auth_chunk remains NULL.
Fix by checking sctp_auth_recv_cid() when auth_chunk is NULL:
if authentication is required, return false to drop the chunk;
otherwise continue normally. |
| In the Linux kernel, the following vulnerability has been resolved:
vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets
vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the
outer header, but for a Geneve-encapsulated packet the device can set
them based on the inner header instead, signalled by the
VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the
function never skips the outer encapsulation, this mismatch triggers:
- BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer
protocol is UDP (Geneve), not TCP.
- BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner
IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa).
Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the
function cannot locate the inner header it would need to parse. Also
convert the remaining BUG_ON()s in this function to return 0
defensively. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create()
Commit 9e9787414882 ("drm/xe/userptr: replace xe_hmm with gpusvm") made
xe_svm_init() unconditional in xe_vm_create() and extended it to also
initialize a "simple" gpusvm state for non-fault-mode VMs. The matching
xe_svm_fini() call in xe_vm_close_and_put() was updated to run
unconditionally, but the error unwind path in xe_vm_create() was not.
On the drm_gpuvm_resv_object_alloc() failure path, xe_svm_init() has
already succeeded but xe_svm_fini() is only called when
XE_VM_FLAG_FAULT_MODE is set. For non-fault-mode VMs this leaves
vm->svm.gpusvm partially initialized and leaks the resources allocated
by drm_gpusvm_init().
For fault-mode VMs, xe_svm_init() additionally acquires the pagemap
owner via drm_pagemap_acquire_owner() and the pagemaps via
xe_svm_get_pagemaps(). Those resources are released by xe_svm_close(),
not xe_svm_fini(). On the same error path, xe_svm_close() is not
called either, so fault-mode VMs leak the pagemap owner and pagemaps.
Fix both leaks:
- Call xe_svm_fini() unconditionally on the err_svm_fini path, matching
the unconditional xe_svm_init() call. Move the vm->size = 0
assignment out of the conditional so the xe_vm_is_closed() assert in
xe_svm_fini() (and xe_svm_close()) holds for both modes.
- Call xe_svm_close() for fault-mode VMs before xe_svm_fini(), matching
the ordering used in xe_vm_close_and_put().
(cherry picked from commit ca2a3587d577ba764e0fe628fb676244fc33ddd4) |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix u16 MTU truncation in media and bearer MTU validation
Both TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied
MTU values but only enforce a minimum bound, not a maximum. When a user
sets the MTU to a value exceeding U16_MAX (65535), it passes validation
but is silently truncated when assigned to u16 fields l->mtu and
l->advertised_mtu in tipc_link_create(). Values like 65536 (0x10000)
truncate to 0, causing a division by zero in tipc_link_set_queue_limits()
which computes TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE). Other overflowing
values (e.g. 65537-131071) produce small incorrect MTU values, resulting
in link malfunction behaviors.
Crash stack (triggered as unprivileged user via user namespace):
tipc_link_set_queue_limits net/tipc/link.c:2531
tipc_link_create net/tipc/link.c:520
tipc_node_check_dest net/tipc/node.c:1279
tipc_disc_rcv net/tipc/discover.c:252
tipc_rcv net/tipc/node.c:2129
tipc_udp_recv net/tipc/udp_media.c:392
Two independent paths lack the upper bound check:
1. tipc_udp_mtu_bad() -- called from __tipc_nl_media_set() (MEDIA_SET)
2. inline check in __tipc_nl_bearer_set() at bearer.c:1160 (BEARER_SET)
Fix both by rejecting MTU values above U16_MAX. |
