| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: gue: reject invalid REMCSUM offsets
The REMCSUM option carries an absolute checksum start and checksum field
offset. gue_remcsum() passes them to skb_remcsum_process(), whose
partial path stores offset - start in the u16 skb->csum_offset variable.
If offset is less than start, this underflows.
A forwarded packet can retain CHECKSUM_PARTIAL and reach a NETIF_F_HW_CSUM
driver which trusts the metadata, leading skb_copy_and_csum_dev() to write
two bytes about 64 KiB beyond the destination buffer.
Reject reversed tuples in validate_gue_flags(), after the existing length
validation, so all GUE parsers enforce the ordering in one place. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: winwing: fix use-after-free in force feedback teardown
winwing_init_ff() passes the driver's private data, allocated with
devm_kzalloc() in winwing_probe(), as the effect context to
input_ff_create_memless(). The memoryless force-feedback core takes
ownership of that pointer and frees it with kfree() from
input_ff_destroy() (ml_ff_destroy()) when the input device is
destroyed.
Freeing a devm-managed allocation with kfree() is an invalid free, and
the same object is then released again by devres when the HID device is
torn down, a double free. As the allocation also embeds the LED class
devices, their timers and work item live on freed memory and the slab
gets corrupted. This triggers on unbind, rmmod, hot-unplug and on system
suspend, where the firmware cache walks the now-corrupt devres list.
KASAN reports:
BUG: KASAN: invalid-free in input_ff_destroy
Allocated by task N:
winwing_probe
Pass NULL as the memless context instead and fetch the driver data from
the input device in winwing_play_effect(): the HID core already stores
the hid_device as the input device's drvdata. The force-feedback core
then owns nothing that it must not free. |
| In the Linux kernel, the following vulnerability has been resolved:
arm64: errata: Mitigate TLBI errata on various Arm CPUs
A number of CPUs developed by Arm suffer from errata whereby a broadcast
TLBI;DSB sequence may complete before the global observation of writes
which are translated by an affected TLB entry.
These errata ONLY affect the completion of memory accesses which have
been translated by an invalidated TLB entry, and these errata DO NOT
affect the actual invalidation of TLB entries. TLB entries are removed
correctly.
This issue has been assigned CVE ID CVE-2025-10263.
To mitigate this issue, Arm recommends that software follows any
affected TLBI;DSB sequence with an additional TLBI;DSB, which will
ensure that all memory write effects affected by the first TLBI have
been globally observed. The additional TLBI can use any operation that
is broadcast to affected CPUs, and the additional DSB can use any option
that is sufficient to complete the additional TLBI.
The ARM64_WORKAROUND_REPEAT_TLBI workaround is sufficient to mitigate
the issue. Enable this workaround for affected CPUs, and update the
silicon errata documentation accordingly.
Note that due to the manner in which Arm develops IP and tracks errata,
some CPUs share a common erratum number. |
| In the Linux kernel, the following vulnerability has been resolved:
tap: free page on error paths in tap_get_user_xdp()
tap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL,
and returns -ENOMEM when build_skb() fails. Both paths jump to the err
label without freeing the page that vhost_net_build_xdp() allocated for
the frame. tap_sendmsg() discards the per-buffer return value and always
returns 0, so vhost_tx_batch() takes the success path and never frees
the page; each rejected frame in a batch leaks one page-frag chunk.
Free the page on both error paths, before the skb is built. This is the
tap counterpart of the same leak in tun_xdp_one(). |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: diag: reject stale associations in dump_one path
The SCTP exact sock_diag lookup can hold a transport reference, block on
lock_sock(sk), and then resume after sctp_association_free() has marked
the association dead and freed its bind address list.
When that happens, inet_assoc_attr_size() and
inet_diag_msg_sctpasoc_fill() can still dereference association state
that is no longer valid for reporting. In particular,
inet_diag_msg_sctpasoc_fill() may read an empty bind-address list as a
real sctp_sockaddr_entry and trigger an out-of-bounds read from
unrelated association memory.
Reject the association after taking the socket lock if it has been
reaped or detached from the endpoint, and report the lookup as stale.
This keeps the exact dump-one path from formatting torn association
state. |
| 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:
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:
KVM: arm64: vgic-its: Drop the translation cache reference only for the erased entry
vgic_its_invalidate_cache() walks the per-ITS translation cache with
xa_for_each() and drops the cache's reference on each entry with
vgic_put_irq(). It puts the iterated pointer, though, rather than the
value returned by xa_erase().
The function is called from contexts that do not exclude one another: the
ITS command handlers hold its_lock, the GITS_CTLR write path holds
cmd_lock, and the path that clears EnableLPIs in a redistributor's
GICR_CTLR holds neither. Two or more of them can drain the same cache
concurrently, and if each one observes the same entry, erases it and then
puts it, the single reference the cache holds on that entry is dropped
more than once. The entry can then be freed while an ITE still maps it.
xa_erase() is atomic and returns the previous entry, so put only the entry
that this context actually removed. The cache reference is then dropped
exactly once per entry even when the invalidations run concurrently, and
the behavior is unchanged when only one context runs. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Nullify "have run CPUs" mask pointer when freeing it
Nullify have_run_cpus when freeing the mask, particularly in the error path
of __sev_guest_init(), so that KVM doesn't have to subtly use sev->active
to track whether or not the mask has been freed. As pointed out by Sashiko,
blindly freeing the mask in sev_vm_destroy() results in a double-free if
the mask is freed if __sev_guest_init() fails.
Throw the logic in a helper as nullifying the pointer is frustratingly
difficult and weird due to have_run_cpus being a single-entry array when
CPUMASK_OFFSTACK=n. Deliberately don't use CPUMASK_VAR_NULL, as it's not
directly assignable when the cpumask is on-stack, e.g. requires using a
local variable and a memcpy(), which is beyond ridiculous. Furthermore,
while clearing the on-stack bitmask is an unnecessary and arguably unwanted
side effect, KVM absolutely relies on '0' being the "null" value given that
the struct is zero-allocated.
Opportunistically add an alloc() helper to pair with free(); there are just
enough call sites to make doing so worthwhile. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Hold map BTF for the memory allocator destructor record
bpf_ma_set_dtor() duplicates map->record so that the bpf_mem_alloc
destructor can release the special fields of hash and rhash map elements
once the allocator frees them for good. btf_record_dup() only acquires
references on kernel and module BTF. Fields whose types live in the map
BTF keep pointing into it: a kptr to a local type refers to map->btf,
and a list_head or rb_root field carries a value_rec owned by the struct
meta table of map->btf.
That borrowed state can outlive the map. When RCU callbacks are still in
flight, bpf_mem_alloc_destroy() copies the allocator and defers the final
drain, together with the destructor context, to a workqueue.
bpf_map_free() then frees map->record and drops the map's BTF reference
as soon as map_free() returns. Once the program that loaded the BTF is
gone as well, the BTF is freed while the worker still uses the
duplicate. The worker dereferences it through btf_is_kernel() and
btf_find_struct_meta() in bpf_obj_free_fields() when destroying elements
that were freed under RCU, and through btf_is_kernel() in
btf_record_free() when releasing the context itself:
BUG: KASAN: slab-use-after-free in btf_is_kernel+0x19/0x30
Read of size 1 at addr ffff88811505dce8 by task kworker/u16:2/50
Workqueue: events_unbound free_mem_alloc_deferred
Call Trace:
btf_is_kernel+0x19/0x30
btf_record_free+0xc7/0xf0
htab_dtor_ctx_free+0x1a/0x30
free_mem_alloc_no_barrier+0x39/0x230
free_mem_alloc_deferred+0x2a/0x40
process_scheduled_works+0x5ce/0x9d0
worker_thread+0x42a/0x5e0
kthread+0x1f5/0x230
ret_from_fork+0x1dd/0x390
ret_from_fork_asm+0x1a/0x30
Allocated by task 358:
__kmalloc_cache_noprof+0x287/0x510
btf_new_fd+0xf7/0x3d0
__sys_bpf+0x487/0x840
Freed by task 0:
kfree+0x186/0x560
rcu_core+0x6f6/0xd40
Freeing a map that still holds more elements than the allocator's high
watermark is enough to get there, because the bulk free during teardown
queues the RCU callback that makes bpf_mem_alloc_destroy() defer.
Non-preallocated hash maps and resizable hash maps both register the
destructor and are affected alike.
Keep one reference on the map BTF in the destructor context. Every
non-kernel pointer in the duplicated record is either map->btf or memory
owned by it, so a single reference covers kptrs, list heads, and rb
roots, and mirrors what bpf_map_meta_alloc() does for the duplicated
record of an inner map. Release it only after the duplicated record has
been freed: the worker is preemptible and not in an RCU read-side
critical section, so dropping the last reference first would let the
BTF be freed while btf_record_free() still reads its fields. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().
Let's wrap mod_timer() and refcount_set() with
preempt_disable_nested() and preempt_enable_nested().
Note that inet_ehash_insert() holds the normal spin_lock()
(mutex in PREEMPT_RT), so it must be called outside of
preempt_disable_nested(), but this is fine.
The lookup path just ignores 0 sk_refcnt entries in ehash
and tries to create another reqsk, but this will fail at
inet_ehash_insert().
[0]:
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: e4 7d d1 0a 67 48 0f b9 3a eb 4a e8 38 3d 23 fd 48 8d 3d e1 7d d1 0a 67 48 0f b9 3a eb 37 e8 25 3d 23 fd 48 8d 3d de 7d d1 0a <67> 48 0f b9 3a eb 24 e8 12 3d 23 fd 48 8d 3d db 7d d1 0a 67 48 0f
RSP: 0000:ffffc90000157948 EFLAGS: 00010246
RAX: ffffffff84a1301b RBX: 0000000000000003 RCX: ffff88801ca98000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8f72ae00
RBP: ffffffff99ae3b01 R08: ffff88801ca98000 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880425ef568
R13: ffff8880425ef4f8 R14: ffff8880425ef578 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126386000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b46710e9c CR3: 000000000dbb6000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
reqsk_put include/net/request_sock.h:136 [inline]
__inet_csk_reqsk_queue_drop+0x3ce/0x440 net/ipv4/inet_connection_sock.c:1007
reqsk_timer_handler+0x651/0xdf0 net/ipv4/inet_connection_sock.c:1137
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0x67/0x170 kernel/time/timer.c:2403
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Fix private hash use-after-free on resize
poll_state_synchronize_rcu(mm->futex.phash.batches) is used by
futex_ref_drop() to check that a grace period has passed since the
current hash was published. This relies on batches referencing a grace
period which started after the hash pointer was assigned.
__futex_pivot_hash() sets mmph->batches before it replaces mmph->hash:
scoped_guard(rcu) {
mmph->batches = get_state_synchronize_rcu();
rcu_assign_pointer(mmph->hash, new);
}
The scoped_guard(rcu) doesn't stop new grace periods from starting, and
if one starts between those two assignments, futex_ref_drop() can move
forward while a reader still holds a pointer to the old hash.
Fix things by setting mmph->batches after assigning mmph->hash. The
scoped_guard(rcu) isn't needed, so let's drop that as well. |
| In the Linux kernel, the following vulnerability has been resolved:
ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
In vti6_tnl_lookup(), when an exact match for a tunnel fails,
the code falls back to searching for wildcard tunnels:
- Tunnels matching the packet's local address, with any remote address
wildcard remote).
- Tunnels matching the packet's remote address, with any local address
(wildcard local).
However, vti6 stores all these different types of tunnels in the same
hash table (ip6n->tnls_r_l) prone to hash collisions.
The bug is that the fallback search loops in vti6_tnl_lookup() were
missing checks to ensure that the candidate tunnel actually has
a wildcard address. |
| In the Linux kernel, the following vulnerability has been resolved:
ip6_vti: set netns_immutable on the fallback device.
john1988 and Noam Rathaus reported that vti6_init_net() does not set the
netns_immutable flag on the per-netns fallback tunnel device (ip6_vti0).
Other similar tunnel drivers (like ip6_tunnel, sit, ip6_gre, and ip_tunnel)
correctly set this flag during their fallback device initialization to
prevent them from being moved to another network namespace. |
| In the Linux kernel, the following vulnerability has been resolved:
inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP
Yizhou Zhao reported that simply having one RAW socket on protocol
IPPROTO_RAW (255) was dangerous.
socket(AF_INET, SOCK_RAW, 255);
A malicious incoming ICMP packet can set the protocol field to 255
and match this socket, leading to FNHE cache changes.
inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST")
pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner
"man 7 raw" states:
A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able
to send any IP protocol that is specified in the passed header.
Receiving of all IP protocols via IPPROTO_RAW is not possible
using raw sockets.
Make sure we drop these malicious packets. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free
nvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the
final controller reference through nvmet_cq_put(). If that triggers
nvmet_ctrl_free(), the teardown path flushes ctrl->async_event_work on
the same nvmet-wq.
Call chain:
nvmet_tcp_schedule_release_queue()
kref_put(&queue->kref, nvmet_tcp_release_queue)
nvmet_tcp_release_queue()
queue_work(nvmet_wq, &queue->release_work) <--- nvmet_wq
process_one_work()
nvmet_tcp_release_queue_work()
nvmet_cq_put(&queue->nvme_cq)
nvmet_cq_destroy()
nvmet_ctrl_put(cq->ctrl)
nvmet_ctrl_free()
flush_work(&ctrl->async_event_work) <--- nvmet_wq
Previously Scheduled by :-
nvmet_add_async_event
queue_work(nvmet_wq, &ctrl->async_event_work);
This trips lockdep with a possible recursive locking warning.
[ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55
[ 5223.061801] loop0: detected capacity change from 0 to 2097152
[ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
[ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420)
[ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
[ 5223.128453] nvme nvme1: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349
[ 5233.199447] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
[ 5233.227718] ============================================
[ 5233.231283] WARNING: possible recursive locking detected
[ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G O N
[ 5233.238434] --------------------------------------------
[ 5233.241852] kworker/u192:6/2413 is trying to acquire lock:
[ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90
[ 5233.251438]
but task is already holding lock:
[ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.261125]
other info that might help us debug this:
[ 5233.265333] Possible unsafe locking scenario:
[ 5233.269217] CPU0
[ 5233.270795] ----
[ 5233.272436] lock((wq_completion)nvmet-wq);
[ 5233.275241] lock((wq_completion)nvmet-wq);
[ 5233.278020]
*** DEADLOCK ***
[ 5233.281793] May be due to missing lock nesting notation
[ 5233.286195] 3 locks held by kworker/u192:6/2413:
[ 5233.289192] #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.294569] #1: ffffc9000e2a7e40 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0
[ 5233.300128] #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530
[ 5233.304290]
stack backtrace:
[ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G O N 7.0.0-rc3nvme+ #20 PREEMPT(full)
[ 5233.306524] Tainted: [O]=OOT_MODULE, [N]=TEST
[ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp]
[ 5233.306532] Call Trace:
[ 5233.306534] <TASK>
[ 5233.306536] dump_stack_lvl+0x73/0xb0
[ 5233.306552] print_deadlock_bug+0x225/0x2f0
[ 5233.306556] __lock_acquire+0x13f0/0x2290
[ 5233.306563] lock_acquire+0xd0/0x300
[ 5233.306565] ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306571] ? __flush_work+0x20b/0x530
[ 5233.306573] ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306577] touch_wq_lockdep_map+0x3b/0x90
[ 5233.306580] ? touch_wq_lockdep_map+0x26/0x90
[ 52
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tun: free page on build_skb failure in tun_xdp_one()
When build_skb() fails in tun_xdp_one(), the function sets ret to
-ENOMEM and jumps to the out label, which returns without freeing the
page that vhost_net_build_xdp() allocated for the frame. As with the
short-frame rejection path, tun_sendmsg() discards the per-buffer error
and still returns total_len, so vhost_tx_batch() takes the success path
and never frees the page. Each build_skb() failure in a batch leaks one
page-frag chunk.
Free the page before taking the error path, matching the put_page() the
other error exits of tun_xdp_one() already perform. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue()
ieee80211_monitor_select_queue() validates the skb length using skb->len
before dereferencing pointers into skb->data to access the 802.11 header.
However, skb->len includes data in both the linear head buffer and
non-linear fragments/pages. When AF_PACKET sends a packet large enough to
become non-linear, the 802.11 header at skb->data + len_rthdr may extend
past the linear head buffer even though skb->len appears sufficient.
This leads to a slab-out-of-bounds read when accessing hdr->frame_control,
as the kernel reads beyond the allocated skb head buffer:
BUG: KASAN: slab-out-of-bounds in ieee80211_monitor_select_queue+0x1ed/0x220
syzbot has hit the same issues.
Fix this by checking skb_headlen(skb) (which gives the length of the
linear data region) instead of skb->len before dereferencing skb->data
pointers. This ensures the required bytes are actually present in the
linear portion of the skb.
Apply the same fix to ieee80211_validate_radiotap_len() which has the
same class of bug: it uses skb->len to validate accesses to skb->data,
and to the corresponding checks in ieee80211_monitor_start_xmit(): for
drivers advertising NETIF_F_SG the skb is not linearized before
ndo_start_xmit, so the 802.11 header can be read past the linear
buffer there as well. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: validate checksum_start before completing checksum
If a packet with bad checksum metadata gets into the ipv4 stack,
skb_checksum_help can corrupt the network header and cause a bunch of
mischief.
This was discovered and reported by Paulos, and has been reporoduced
by others independently since.
We really shouldn't allow such packets in, but as a defence
in depth measure, let's also check before we complete the checksum.
A more complete validation at input is forthcoming, but needs more work. |
| In the Linux kernel, the following vulnerability has been resolved:
dm thin metadata: fix metadata snapshot consistency on commit failure
__reserve_metadata_snap() and __release_metadata_snap() modify the
superblock's held_root directly in the block_manager's buffer. If the
subsequent metadata commit fails, the held_root gets flushed to disk
through the abort_transaction path, resulting in inconsistent metadata.
Reproducer 1: __reserve_metadata_snap()
1. Create a 2 MiB metadata device and make the region after the 14th
block inaccessible, to trigger metadata commit failure in the
subsequent reserve_metadata_snap operation. The 14th block will be
the shadow destination for the index block.
dmsetup create tmeta --table "0 112 linear /dev/sdc 0
112 3984 error"
2. Create a 16 MiB thin-pool
dmsetup create tdata --table "0 32768 zero"
dd if=/dev/zero of=/dev/mapper/tmeta bs=4k count=1
dmsetup create tpool --table "0 32768 thin-pool /dev/mapper/tmeta \
/dev/mapper/tdata 128 0 1 skip_block_zeroing"
3. Take a metadata snapshot to trigger metadata commit failure and
transaction abort. However, the held_root is written to disk,
breaking metadata consistency.
dmsetup message tpool 0 "reserve_metadata_snap"
thin_check v1.2.2 result:
Bad reference count for metadata block 6. Expected 2, but space map contains 1.
Bad reference count for metadata block 7. Expected 2, but space map contains 1.
Bad reference count for metadata block 13. Expected 1, but space map contains 0.
Reproducer 2: __release_metadata_snap()
1. Create a 2 MiB metadata device and make the region after the 16th
block inaccessible, to trigger metadata commit failure in the
subsequent release_metadata_snap operation. The 16th block will be
the shadow destination for the index block.
dmsetup create tmeta --table "0 128 linear /dev/sdc 0
128 3968 error"
2. Create a 16 MiB thin-pool
dmsetup create tdata --table "0 32768 zero"
dd if=/dev/zero of=/dev/mapper/tmeta bs=4k count=1
dmsetup create tpool --table "0 32768 thin-pool /dev/mapper/tmeta \
/dev/mapper/tdata 128 0 1 skip_block_zeroing"
3. Reserve then release the metadata snapshot, to trigger metadata
commit failure and transaction abort. The held_root gets removed
from the on-disk superblock, causing inconsistent metadata.
dmsetup message tpool 0 "reserve_metadata_snap"
dmsetup message tpool 0 "release_metadata_snap"
thin_check v1.2.2 result:
Bad reference count for metadata block 6. Expected 1, but space map contains 2.
Bad reference count for metadata block 7. Expected 1, but space map contains 2.
1 metadata blocks have leaked.
Fix by deferring the held_root update to commit time.
Additionally, move the existing-snapshot check in __reserve_metadata_snap
before the shadow operation to avoid unnecessary work. In
__release_metadata_snap, clear pmd->held_root before btree deletion so
partial failure leaks blocks rather than leaving a stale reference, and
unlock the snapshot block before decrementing its refcount. |
