| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: disable BH before calling udp_tunnel_xmit_skb()
udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with
BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to
tunnel xmit functions"), on the path:
udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit()
dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU.
Without local_bh_disable(), the context may move between CPUs, which can
break the inc/dec pairing. This may lead to incorrect recursion level
detection and cause packets to be dropped in ip(6)_tunnel_xmit() or
__dev_queue_xmit().
Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths.
In my testing, after enabling the SCTP over UDP:
# ip net exec ha sysctl -w net.sctp.udp_port=9899
# ip net exec ha sysctl -w net.sctp.encap_port=9899
# ip net exec hb sysctl -w net.sctp.udp_port=9899
# ip net exec hb sysctl -w net.sctp.encap_port=9899
# ip net exec ha iperf3 -s
- without this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender
[ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver
- with this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Take state lock for af_unix iter
When a BPF iterator program updates a sockmap, there is a race condition in
unix_stream_bpf_update_proto() where the `peer` pointer can become stale[1]
during a state transition TCP_ESTABLISHED -> TCP_CLOSE.
CPU0 bpf CPU1 close
-------- ----------
// unix_stream_bpf_update_proto()
sk_pair = unix_peer(sk)
if (unlikely(!sk_pair))
return -EINVAL;
// unix_release_sock()
skpair = unix_peer(sk);
unix_peer(sk) = NULL;
sock_put(skpair)
sock_hold(sk_pair) // UaF
More practically, this fix guarantees that the iterator program is
consistently provided with a unix socket that remains stable during
iterator execution.
[1]:
BUG: KASAN: slab-use-after-free in unix_stream_bpf_update_proto+0x155/0x490
Write of size 4 at addr ffff8881178c9a00 by task test_progs/2231
Call Trace:
dump_stack_lvl+0x5d/0x80
print_report+0x170/0x4f3
kasan_report+0xe4/0x1c0
kasan_check_range+0x125/0x200
unix_stream_bpf_update_proto+0x155/0x490
sock_map_link+0x71c/0xec0
sock_map_update_common+0xbc/0x600
sock_map_update_elem+0x19a/0x1f0
bpf_prog_bbbf56096cdd4f01_selective_dump_unix+0x20c/0x217
bpf_iter_run_prog+0x21e/0xae0
bpf_iter_unix_seq_show+0x1e0/0x2a0
bpf_seq_read+0x42c/0x10d0
vfs_read+0x171/0xb20
ksys_read+0xff/0x200
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x63/0x80
kmem_cache_alloc_noprof+0x1d5/0x680
sk_prot_alloc+0x59/0x210
sk_alloc+0x34/0x470
unix_create1+0x86/0x8a0
unix_stream_connect+0x318/0x15b0
__sys_connect+0xfd/0x130
__x64_sys_connect+0x72/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x47/0x70
kmem_cache_free+0x11c/0x590
__sk_destruct+0x432/0x6e0
unix_release_sock+0x9b3/0xf60
unix_release+0x8a/0xf0
__sock_release+0xb0/0x270
sock_close+0x18/0x20
__fput+0x36e/0xac0
fput_close_sync+0xe5/0x1a0
__x64_sys_close+0x7d/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: taprio: fix use-after-free in advance_sched() on schedule switch
In advance_sched(), when should_change_schedules() returns true,
switch_schedules() is called to promote the admin schedule to oper.
switch_schedules() queues the old oper schedule for RCU freeing via
call_rcu(), but 'next' still points into an entry of the old oper
schedule. The subsequent 'next->end_time = end_time' and
rcu_assign_pointer(q->current_entry, next) are use-after-free.
Fix this by selecting 'next' from the new oper schedule immediately
after switch_schedules(), and using its pre-calculated end_time.
setup_first_end_time() sets the first entry's end_time to
base_time + interval when the schedule is installed, so the value
is already correct.
The deleted 'end_time = sched_base_time(admin)' assignment was also
harmful independently: it would overwrite the new first entry's
pre-calculated end_time with just base_time. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: join hook list via splice_list_rcu() in commit phase
Publish new hooks in the list into the basechain/flowtable using
splice_list_rcu() to ensure netlink dump list traversal via rcu is safe
while concurrent ruleset update is going on. |
| In the Linux kernel, the following vulnerability has been resolved:
bonding: 3ad: implement proper RCU rules for port->aggregator
syzbot found a data-race in bond_3ad_get_active_agg_info /
bond_3ad_state_machine_handler [1] which hints at lack of proper
RCU implementation.
Add __rcu qualifier to port->aggregator, and add proper RCU API.
[1]
BUG: KCSAN: data-race in bond_3ad_get_active_agg_info / bond_3ad_state_machine_handler
write to 0xffff88813cf5c4b0 of 8 bytes by task 36 on cpu 0:
ad_port_selection_logic drivers/net/bonding/bond_3ad.c:1659 [inline]
bond_3ad_state_machine_handler+0x9d5/0x2d60 drivers/net/bonding/bond_3ad.c:2569
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3385
worker_thread+0x58a/0x780 kernel/workqueue.c:3466
kthread+0x22a/0x280 kernel/kthread.c:436
ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
read to 0xffff88813cf5c4b0 of 8 bytes by task 22063 on cpu 1:
__bond_3ad_get_active_agg_info drivers/net/bonding/bond_3ad.c:2858 [inline]
bond_3ad_get_active_agg_info+0x8c/0x230 drivers/net/bonding/bond_3ad.c:2881
bond_fill_info+0xe0f/0x10f0 drivers/net/bonding/bond_netlink.c:853
rtnl_link_info_fill net/core/rtnetlink.c:906 [inline]
rtnl_link_fill+0x1d7/0x4e0 net/core/rtnetlink.c:927
rtnl_fill_ifinfo+0xf8e/0x1380 net/core/rtnetlink.c:2168
rtmsg_ifinfo_build_skb+0x11c/0x1b0 net/core/rtnetlink.c:4453
rtmsg_ifinfo_event net/core/rtnetlink.c:4486 [inline]
rtmsg_ifinfo+0x6d/0x110 net/core/rtnetlink.c:4495
__dev_notify_flags+0x76/0x390 net/core/dev.c:9790
netif_change_flags+0xac/0xd0 net/core/dev.c:9823
do_setlink+0x905/0x2950 net/core/rtnetlink.c:3180
rtnl_group_changelink net/core/rtnetlink.c:3813 [inline]
__rtnl_newlink net/core/rtnetlink.c:3981 [inline]
rtnl_newlink+0xf55/0x1400 net/core/rtnetlink.c:4109
rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6995
netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7022
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x563/0x5b0 net/socket.c:2698
___sys_sendmsg+0x195/0x1e0 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787
x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x0000000000000000 -> 0xffff88813cf5c400
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22063 Comm: syz.0.31122 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 |
| In the Linux kernel, the following vulnerability has been resolved:
net: ena: PHC: Fix potential use-after-free in get_timestamp
Move the phc->active check and resp pointer assignment to after
acquiring the spinlock. Previously, phc->active was checked without
holding the lock, and resp was cached from ena_dev->phc.virt_addr
before the lock was acquired.
If ena_com_phc_destroy() runs between the lockless active check and
the lock acquisition, it sets active=false, releases the lock, frees
the DMA memory, and sets virt_addr=NULL. The get_timestamp path would
then read a NULL virt_addr and dereference it.
With both the active check and the pointer read under the lock,
destroy cannot free the memory while get_timestamp is using it. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tp_meter: avoid use of uninit sender vars
batadv_tp_recv_ack() and batadv_tp_stop() are only valid for tp_vars in the
BATADV_TP_SENDER role. When called with a BATADV_TP_RECEIVER role, it
proceeds to read sender-only members that were never initialized, leading
to undefined behavior.
This can be triggered when a node that is currently acting as a receiver in
an ongoing tp_meter session receives a malicious ACK packet.
Guard against this by checking tp_vars->role immediately after the
lookup and bailing out if it is not BATADV_TP_SENDER, before any of
those members are accessed. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: purge outqueue on stale COOKIE-ECHO handling
sctp_stream_update() is only invoked when the association is moved into
COOKIE_WAIT during association setup/reconfiguration. In this path, the
outbound stream scheduler state (stream->out_curr) is expected to be
clean, since no user data should have been transmitted yet unless the
state machine has already partially progressed.
However, a corner case exists in sctp_sf_do_5_2_6_stale(): when a
Stale Cookie ERROR is received, the association is rolled back from
COOKIE_ECHOED to COOKIE_WAIT. In this scenario, user data may already
have been queued and even bundled with the COOKIE-ECHO chunk.
During the rollback, sctp_stream_update() frees the old stream table
and installs a new one, but it does not invalidate stream->out_curr.
As a result, out_curr may still point to a freed sctp_stream_out
entry from the previous stream state.
Later, SCTP scheduler dequeue paths (FCFS, RR, PRIO, etc.) rely on
stream->out_curr->ext, which can lead to use-after-free once the old
stream state has been released via sctp_stream_free().
This results in crashes such as (reported by Yuqi):
BUG: KASAN: slab-use-after-free in sctp_sched_fcfs_dequeue+0x13a/0x140
Read of size 8 at addr ff1100004d4d3208 by task mini_poc/9312
CPU: 1 UID: 1001 PID: 9312 Comm: mini_poc Not tainted
7.1.0-rc1-00305-gbd3a4795d574 #5 PREEMPT(full)
sctp_sched_fcfs_dequeue+0x13a/0x140
sctp_outq_flush+0x1603/0x33e0
sctp_do_sm+0x31c9/0x5d30
sctp_assoc_bh_rcv+0x392/0x6f0
sctp_inq_push+0x1db/0x270
sctp_rcv+0x138d/0x3c10
Fix this by fully purging the association outqueue when handling the
Stale Cookie case. This ensures all pending transmit and retransmit
state is dropped, and any scheduler cached pointers are invalidated,
making it safe to rebuild stream state during COOKIE_WAIT restart.
Updating only stream->out_curr would be insufficient, since queued
and retransmittable data would still reference the old stream state and
trigger later use-after-free in dequeue paths. |
| In the Linux kernel, the following vulnerability has been resolved:
ipc: limit next_id allocation to the valid ID range
The checkpoint/restore sysctl path can request the next SysV IPC id
through ids->next_id. ipc_idr_alloc() currently forwards that request to
idr_alloc() with an open-ended upper bound.
If the valid tail of the SysV IPC id space is full, the allocation can
spill beyond ipc_mni. The returned SysV IPC id still uses the normal
index encoding, so later lookup and removal can target the wrong slot.
This leaves the real IDR entry behind and breaks the IDR state for the
object.
The bug is in ipc_idr_alloc() in the checkpoint/restore path.
1. ids->next_id is passed to:
idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, ...)
2. The zero upper bound makes the allocation effectively open-ended.
Once the valid SysV IPC tail is occupied, idr_alloc() can spill past
ipc_mni and allocate an entry beyond the valid IPC id range.
3. The new object id is still encoded with the narrower SysV IPC index
width:
new->id = (new->seq << ipcmni_seq_shift()) + idx
4. Later removal goes through ipc_rmid(), which uses:
ipcid_to_idx(ipcp->id)
That truncates the real IDR index. An object actually stored at a
high index can then be removed as if it lived at a low in-range
index.
5. For shared memory, shm_destroy() frees the current object anyway, but
the real high IDR slot is left behind as a dangling pointer.
6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry
and dereferences freed memory.
Prevent this by bounding the requested allocation to ipc_mni so the
checkpoint/restore path fails once the valid range is exhausted. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: serialize accept_q access
bt_sock_poll() walks the accept queue without synchronization, while
child teardown can unlink the same socket and drop its last reference.
The unsynchronized accept queue walk has existed since the initial
Bluetooth import.
Protect accept_q with a dedicated lock for queue updates and polling.
Also rework bt_accept_dequeue() to take temporary child references under
the queue lock before dropping it and locking the child socket. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE
The current implementation incorrectly handles memory regions (MRs) with
page sizes different from the system PAGE_SIZE. The core issue is that
rxe_set_page() is called with mr->page_size step increments, but the
page_list stores individual struct page pointers, each representing
PAGE_SIZE of memory.
ib_sg_to_page() has ensured that when i>=1 either
a) SG[i-1].dma_end and SG[i].dma_addr are contiguous
or
b) SG[i-1].dma_end and SG[i].dma_addr are mr->page_size aligned.
This leads to incorrect iova-to-va conversion in scenarios:
1) page_size < PAGE_SIZE (e.g., MR: 4K, system: 64K):
ibmr->iova = 0x181800
sg[0]: dma_addr=0x181800, len=0x800
sg[1]: dma_addr=0x173000, len=0x1000
Access iova = 0x181800 + 0x810 = 0x182010
Expected VA: 0x173010 (second SG, offset 0x10)
Before fix:
- index = (0x182010 >> 12) - (0x181800 >> 12) = 1
- page_offset = 0x182010 & 0xFFF = 0x10
- xarray[1] stores system page base 0x170000
- Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong)
2) page_size > PAGE_SIZE (e.g., MR: 64K, system: 4K):
ibmr->iova = 0x18f800
sg[0]: dma_addr=0x18f800, len=0x800
sg[1]: dma_addr=0x170000, len=0x1000
Access iova = 0x18f800 + 0x810 = 0x190010
Expected VA: 0x170010 (second SG, offset 0x10)
Before fix:
- index = (0x190010 >> 16) - (0x18f800 >> 16) = 1
- page_offset = 0x190010 & 0xFFFF = 0x10
- xarray[1] stores system page for dma_addr 0x170000
- Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong)
Yi Zhang reported a kernel panic[1] years ago related to this defect.
Solution:
1. Replace xarray with pre-allocated rxe_mr_page array for sequential
indexing (all MR page indices are contiguous)
2. Each rxe_mr_page stores both struct page* and offset within the
system page
3. Handle MR page_size != PAGE_SIZE relationships:
- page_size > PAGE_SIZE: Split MR pages into multiple system pages
- page_size <= PAGE_SIZE: Store offset within system page
4. Add boundary checks and compatibility validation
This ensures correct iova-to-va conversion regardless of MR page size
and system PAGE_SIZE relationship, while improving performance through
array-based sequential access.
Tests on 4K and 64K PAGE_SIZE hosts:
- rdma-core/pytests
$ ./build/bin/run_tests.py --dev eth0_rxe
- blktest:
$ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd
[1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/ |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_ct: Only release RCU read lock after ct_ft
When looking up a flow table in act_ct in tcf_ct_flow_table_get(),
rhashtable_lookup_fast() internally opens and closes an RCU read critical
section before returning ct_ft.
The tcf_ct_flow_table_cleanup_work() can complete before refcount_inc_not_zero()
is invoked on the returned ct_ft resulting in a UAF on the already freed ct_ft
object. This vulnerability can lead to privilege escalation.
Analysis from zdi-disclosures@trendmicro.com:
When initializing act_ct, tcf_ct_init() is called, which internally triggers
tcf_ct_flow_table_get().
static int tcf_ct_flow_table_get(struct net *net, struct tcf_ct_params *params)
{
struct zones_ht_key key = { .net = net, .zone = params->zone };
struct tcf_ct_flow_table *ct_ft;
int err = -ENOMEM;
mutex_lock(&zones_mutex);
ct_ft = rhashtable_lookup_fast(&zones_ht, &key, zones_params); // [1]
if (ct_ft && refcount_inc_not_zero(&ct_ft->ref)) // [2]
goto out_unlock;
...
}
static __always_inline void *rhashtable_lookup_fast(
struct rhashtable *ht, const void *key,
const struct rhashtable_params params)
{
void *obj;
rcu_read_lock();
obj = rhashtable_lookup(ht, key, params);
rcu_read_unlock();
return obj;
}
At [1], rhashtable_lookup_fast() looks up and returns the corresponding ct_ft
from zones_ht . The lookup is performed within an RCU read critical section
through rcu_read_lock() / rcu_read_unlock(), which prevents the object from
being freed. However, at the point of function return, rcu_read_unlock() has
already been called, and there is nothing preventing ct_ft from being freed
before reaching refcount_inc_not_zero(&ct_ft->ref) at [2]. This interval becomes
the race window, during which ct_ft can be freed.
Free Process:
tcf_ct_flow_table_put() is executed through the path tcf_ct_cleanup() call_rcu()
tcf_ct_params_free_rcu() tcf_ct_params_free() tcf_ct_flow_table_put().
static void tcf_ct_flow_table_put(struct tcf_ct_flow_table *ct_ft)
{
if (refcount_dec_and_test(&ct_ft->ref)) {
rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
INIT_RCU_WORK(&ct_ft->rwork, tcf_ct_flow_table_cleanup_work); // [3]
queue_rcu_work(act_ct_wq, &ct_ft->rwork);
}
}
At [3], tcf_ct_flow_table_cleanup_work() is scheduled as RCU work
static void tcf_ct_flow_table_cleanup_work(struct work_struct *work)
{
struct tcf_ct_flow_table *ct_ft;
struct flow_block *block;
ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table,
rwork);
nf_flow_table_free(&ct_ft->nf_ft);
block = &ct_ft->nf_ft.flow_block;
down_write(&ct_ft->nf_ft.flow_block_lock);
WARN_ON(!list_empty(&block->cb_list));
up_write(&ct_ft->nf_ft.flow_block_lock);
kfree(ct_ft); // [4]
module_put(THIS_MODULE);
}
tcf_ct_flow_table_cleanup_work() frees ct_ft at [4]. When this function executes
between [1] and [2], UAF occurs.
This race condition has a very short race window, making it generally
difficult to trigger. Therefore, to trigger the vulnerability an msleep(100) was
inserted after[1] |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Reassign nested_mmus array behind mmu_lock
kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the
MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which
can run at any time. kvm_vcpu_init_nested() reallocates the array and frees
the old buffer while holding only kvm->arch.config_lock, so such a walker
can reference the freed array.
Allocate the new array outside of mmu_lock, as the allocation can sleep.
Under the lock, copy the existing entries, fix up the back pointers and
reassign the array. Free the old buffer after dropping the lock, as
kvfree() can sleep as well. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/userq: fix access to stale wptr mapping
Use drm_exec to take both locks i.e vm root bo and
wptr_obj bo to access the mapping data properly.
This fixes the security issue of unmap the wptr_obj while
a queue creation is in progress and passing other
bo at same address.
(cherry picked from commit 1fc6c8ab45dbee096469c08c13f6099d57a52d6c) |
| In the Linux kernel, the following vulnerability has been resolved:
lib: test_hmm: evict device pages on file close to avoid use-after-free
Patch series "Minor hmm_test fixes and cleanups".
Two bugfixes a cleanup for the HMM kernel selftests. These were mostly
reported by Zenghui Yu with special thanks to Lorenzo for analysing and
pointing out the problems.
This patch (of 3):
When dmirror_fops_release() is called it frees the dmirror struct but
doesn't migrate device private pages back to system memory first. This
leaves those pages with a dangling zone_device_data pointer to the freed
dmirror.
If a subsequent fault occurs on those pages (eg. during coredump) the
dmirror_devmem_fault() callback dereferences the stale pointer causing a
kernel panic. This was reported [1] when running mm/ksft_hmm.sh on arm64,
where a test failure triggered SIGABRT and the resulting coredump walked
the VMAs faulting in the stale device private pages.
Fix this by calling dmirror_device_evict_chunk() for each devmem chunk in
dmirror_fops_release() to migrate all device private pages back to system
memory before freeing the dmirror struct. The function is moved earlier
in the file to avoid a forward declaration. |
| In the Linux kernel, the following vulnerability has been resolved:
procfs: fix missing RCU protection when reading real_parent in do_task_stat()
When reading /proc/[pid]/stat, do_task_stat() accesses task->real_parent
without proper RCU protection, which leads to:
cpu 0 cpu 1
----- -----
do_task_stat
var = task->real_parent
release_task
call_rcu(delayed_put_task_struct)
task_tgid_nr_ns(var)
rcu_read_lock <--- Too late to protect task->real_parent!
task_pid_ptr <--- UAF!
rcu_read_unlock
This patch uses task_ppid_nr_ns() instead of task_tgid_nr_ns() to add
proper RCU protection for accessing task->real_parent. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_inner: Fix IPv6 inner_thoff desync
In nft_inner_parse_l2l3(), when processing inner IPv6 packets,
ipv6_find_hdr() correctly computes the transport header offset
traversing all extension headers, but the result is immediately
overwritten with nhoff + sizeof(_ip6h) (40 bytes), which only
accounts for the IPv6 base header. This creates a desync between
inner_thoff (wrong — points to extension header start) and l4proto
(correct — e.g., IPPROTO_TCP), enabling transport header forgery
and potential firewall bypass. This issue affects stable versions
from Linux 6.2.
For comparison, the normal (non-inner) IPv6 path correctly
preserves ipv6_find_hdr()'s result. Removing the incorrect overwrite
ensures that ipv6_find_hdr()'s calculated transport header offset is
preserved, thereby fixing the desynchronization. |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.
Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: call sk_data_ready() after listener migration
When inet_csk_listen_stop() migrates an established child socket from
a closing listener to another socket in the same SO_REUSEPORT group,
the target listener gets a new accept-queue entry via
inet_csk_reqsk_queue_add(), but that path never notifies the target
listener's waiters. A nonblocking accept() still works because it
checks the queue directly, but poll()/epoll_wait() waiters and
blocking accept() callers can also remain asleep indefinitely.
Call READ_ONCE(nsk->sk_data_ready)(nsk) after a successful migration
in inet_csk_listen_stop().
However, after inet_csk_reqsk_queue_add() succeeds, the ref acquired
in reuseport_migrate_sock() is effectively transferred to
nreq->rsk_listener. Another CPU can then dequeue nreq via accept()
or listener shutdown, hit reqsk_put(), and drop that listener ref.
Since listeners are SOCK_RCU_FREE, wrap the post-queue_add()
dereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also
covers the existing sock_net(nsk) access in that path.
The reqsk_timer_handler() path does not need the same changes for two
reasons: half-open requests become readable only after the final ACK,
where tcp_child_process() already wakes the listener; and once nreq is
visible via inet_ehash_insert(), the success path no longer touches
nsk directly. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Flush cache for PASID table before using it
When writing the address of a freshly allocated zero-initialized PASID
table to a PASID directory entry, do that after the CPU cache flush for
this PASID table, not before it, to avoid the time window when this
PASID table may be already used by non-coherent IOMMU hardware while
its contents in RAM is still some random old data, not zero-initialized. |
