| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: xen: scsiback: Fix potential memory leak in scsiback_remove()
Memory allocated for struct vscsiblk_info in scsiback_probe() is not
freed in scsiback_remove() leading to potential memory leaks on remove,
as well as in the scsiback_probe() error paths. Fix that by freeing it
in scsiback_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: cap TX credit to local buffer size
The virtio transports derives its TX credit directly from peer_buf_alloc,
which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value.
On the host side this means that the amount of data we are willing to
queue for a connection is scaled by a guest-chosen buffer size, rather
than the host's own vsock configuration. A malicious guest can advertise
a large buffer and read slowly, causing the host to allocate a
correspondingly large amount of sk_buff memory.
The same thing would happen in the guest with a malicious host, since
virtio transports share the same code base.
Introduce a small helper, virtio_transport_tx_buf_size(), that
returns min(peer_buf_alloc, buf_alloc), and use it wherever we consume
peer_buf_alloc.
This ensures the effective TX window is bounded by both the peer's
advertised buffer and our own buf_alloc (already clamped to
buffer_max_size via SO_VM_SOCKETS_BUFFER_MAX_SIZE), so a remote peer
cannot force the other to queue more data than allowed by its own
vsock settings.
On an unpatched Ubuntu 22.04 host (~64 GiB RAM), running a PoC with
32 guest vsock connections advertising 2 GiB each and reading slowly
drove Slab/SUnreclaim from ~0.5 GiB to ~57 GiB; the system only
recovered after killing the QEMU process. That said, if QEMU memory is
limited with cgroups, the maximum memory used will be limited.
With this patch applied:
Before:
MemFree: ~61.6 GiB
Slab: ~142 MiB
SUnreclaim: ~117 MiB
After 32 high-credit connections:
MemFree: ~61.5 GiB
Slab: ~178 MiB
SUnreclaim: ~152 MiB
Only ~35 MiB increase in Slab/SUnreclaim, no host OOM, and the guest
remains responsive.
Compatibility with non-virtio transports:
- VMCI uses the AF_VSOCK buffer knobs to size its queue pairs per
socket based on the local vsk->buffer_* values; the remote side
cannot enlarge those queues beyond what the local endpoint
configured.
- Hyper-V's vsock transport uses fixed-size VMBus ring buffers and
an MTU bound; there is no peer-controlled credit field comparable
to peer_buf_alloc, and the remote endpoint cannot drive in-flight
kernel memory above those ring sizes.
- The loopback path reuses virtio_transport_common.c, so it
naturally follows the same semantics as the virtio transport.
This change is limited to virtio_transport_common.c and thus affects
virtio-vsock, vhost-vsock, and loopback, bringing them in line with the
"remote window intersected with local policy" behaviour that VMCI and
Hyper-V already effectively have.
[Stefano: small adjustments after changing the previous patch]
[Stefano: tweak the commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
be2net: Fix NULL pointer dereference in be_cmd_get_mac_from_list
When the parameter pmac_id_valid argument of be_cmd_get_mac_from_list() is
set to false, the driver may request the PMAC_ID from the firmware of the
network card, and this function will store that PMAC_ID at the provided
address pmac_id. This is the contract of this function.
However, there is a location within the driver where both
pmac_id_valid == false and pmac_id == NULL are being passed. This could
result in dereferencing a NULL pointer.
To resolve this issue, it is necessary to pass the address of a stub
variable to the function. |
| In the Linux kernel, the following vulnerability has been resolved:
fou: Don't allow 0 for FOU_ATTR_IPPROTO.
fou_udp_recv() has the same problem mentioned in the previous
patch.
If FOU_ATTR_IPPROTO is set to 0, skb is not freed by
fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu().
Let's forbid 0 for FOU_ATTR_IPPROTO. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix recvmsg() unconditional requeue
If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at
the front of the recvmsg queue already has its mutex locked, it requeues
the call - whether or not the call is already queued. The call may be on
the queue because MSG_PEEK was also passed and so the call was not dequeued
or because the I/O thread requeued it.
The unconditional requeue may then corrupt the recvmsg queue, leading to
things like UAFs or refcount underruns.
Fix this by only requeuing the call if it isn't already on the queue - and
moving it to the front if it is already queued. If we don't queue it, we
have to put the ref we obtained by dequeuing it.
Also, MSG_PEEK doesn't dequeue the call so shouldn't call
rxrpc_notify_socket() for the call if we didn't use up all the data on the
queue, so fix that also. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: authencesn - reject too-short AAD (assoclen<8) to match ESP/ESN spec
authencesn assumes an ESP/ESN-formatted AAD. When assoclen is shorter than
the minimum expected length, crypto_authenc_esn_decrypt() can advance past
the end of the destination scatterlist and trigger a NULL pointer dereference
in scatterwalk_map_and_copy(), leading to a kernel panic (DoS).
Add a minimum AAD length check to fail fast on invalid inputs. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hv_netvsc: reject RSS hash key programming without RX indirection table
RSS configuration requires a valid RX indirection table. When the device
reports a single receive queue, rndis_filter_device_add() does not
allocate an indirection table, accepting RSS hash key updates in this
state leads to a hang.
Fix this by gating netvsc_set_rxfh() on ndc->rx_table_sz and return
-EOPNOTSUPP when the table is absent. This aligns set_rxfh with the device
capabilities and prevents incorrect behavior. |
| In the Linux kernel, the following vulnerability has been resolved:
pnfs/flexfiles: Fix memory leak in nfs4_ff_alloc_deviceid_node()
In nfs4_ff_alloc_deviceid_node(), if the allocation for ds_versions fails,
the function jumps to the out_scratch label without freeing the already
allocated dsaddrs list, leading to a memory leak.
Fix this by jumping to the out_err_drain_dsaddrs label, which properly
frees the dsaddrs list before cleaning up other resources. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: qcom: gpi: Fix memory leak in gpi_peripheral_config()
Fix a memory leak in gpi_peripheral_config() where the original memory
pointed to by gchan->config could be lost if krealloc() fails.
The issue occurs when:
1. gchan->config points to previously allocated memory
2. krealloc() fails and returns NULL
3. The function directly assigns NULL to gchan->config, losing the
reference to the original memory
4. The original memory becomes unreachable and cannot be freed
Fix this by using a temporary variable to hold the krealloc() result
and only updating gchan->config when the allocation succeeds.
Found via static analysis and code review. |
| In the Linux kernel, the following vulnerability has been resolved:
net: marvell: prestera: fix NULL dereference on devlink_alloc() failure
devlink_alloc() may return NULL on allocation failure, but
prestera_devlink_alloc() unconditionally calls devlink_priv() on
the returned pointer.
This leads to a NULL pointer dereference if devlink allocation fails.
Add a check for a NULL devlink pointer and return NULL early to avoid
the crash. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: ip_gre: make ipgre_header() robust
Analog to commit db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust")
Over the years, syzbot found many ways to crash the kernel
in ipgre_header() [1].
This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len
In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ipgre device.
[1]
skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0
kernel BUG at net/core/skbuff.c:213 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: mld mld_ifc_work
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213
Call Trace:
<TASK>
skb_under_panic net/core/skbuff.c:223 [inline]
skb_push+0xc3/0xe0 net/core/skbuff.c:2641
ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897
dev_hard_header include/linux/netdevice.h:3436 [inline]
neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: Fix use-after-free in inet6_addr_del().
syzbot reported use-after-free of inet6_ifaddr in
inet6_addr_del(). [0]
The cited commit accidentally moved ipv6_del_addr() for
mngtmpaddr before reading its ifp->flags for temporary
addresses in inet6_addr_del().
Let's move ipv6_del_addr() down to fix the UAF.
[0]:
BUG: KASAN: slab-use-after-free in inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117
Read of size 4 at addr ffff88807b89c86c by task syz.3.1618/9593
CPU: 0 UID: 0 PID: 9593 Comm: syz.3.1618 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117
addrconf_del_ifaddr+0x11e/0x190 net/ipv6/addrconf.c:3181
inet6_ioctl+0x1e5/0x2b0 net/ipv6/af_inet6.c:582
sock_do_ioctl+0x118/0x280 net/socket.c:1254
sock_ioctl+0x227/0x6b0 net/socket.c:1375
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f164cf8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f164de64038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f164d1e5fa0 RCX: 00007f164cf8f749
RDX: 0000200000000000 RSI: 0000000000008936 RDI: 0000000000000003
RBP: 00007f164d013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f164d1e6038 R14: 00007f164d1e5fa0 R15: 00007ffde15c8288
</TASK>
Allocated by task 9593:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
ipv6_add_addr+0x4e3/0x2010 net/ipv6/addrconf.c:1120
inet6_addr_add+0x256/0x9b0 net/ipv6/addrconf.c:3050
addrconf_add_ifaddr+0x1fc/0x450 net/ipv6/addrconf.c:3160
inet6_ioctl+0x103/0x2b0 net/ipv6/af_inet6.c:580
sock_do_ioctl+0x118/0x280 net/socket.c:1254
sock_ioctl+0x227/0x6b0 net/socket.c:1375
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6099:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free_freelist_hook mm/slub.c:2569 [inline]
slab_free_bulk mm/slub.c:6696 [inline]
kmem_cache_free_bulk mm/slub.c:7383 [inline]
kmem_cache_free_bulk+0x2bf/0x680 mm/slub.c:7362
kfree_bulk include/linux/slab.h:830 [inline]
kvfree_rcu_bulk+0x1b7/0x1e0 mm/slab_common.c:1523
kvfree_rcu_drain_ready mm/slab_common.c:1728 [inline]
kfree_rcu_monitor+0x1d0/0x2f0 mm/slab_common.c:1801
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqu
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
x86/fpu: Clear XSTATE_BV[i] in guest XSAVE state whenever XFD[i]=1
When loading guest XSAVE state via KVM_SET_XSAVE, and when updating XFD in
response to a guest WRMSR, clear XFD-disabled features in the saved (or to
be restored) XSTATE_BV to ensure KVM doesn't attempt to load state for
features that are disabled via the guest's XFD. Because the kernel
executes XRSTOR with the guest's XFD, saving XSTATE_BV[i]=1 with XFD[i]=1
will cause XRSTOR to #NM and panic the kernel.
E.g. if fpu_update_guest_xfd() sets XFD without clearing XSTATE_BV:
------------[ cut here ]------------
WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#29: amx_test/848
Modules linked in: kvm_intel kvm irqbypass
CPU: 29 UID: 1000 PID: 848 Comm: amx_test Not tainted 6.19.0-rc2-ffa07f7fd437-x86_amx_nm_xfd_non_init-vm #171 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:exc_device_not_available+0x101/0x110
Call Trace:
<TASK>
asm_exc_device_not_available+0x1a/0x20
RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90
switch_fpu_return+0x4a/0xb0
kvm_arch_vcpu_ioctl_run+0x1245/0x1e40 [kvm]
kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm]
__x64_sys_ioctl+0x8f/0xd0
do_syscall_64+0x62/0x940
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
This can happen if the guest executes WRMSR(MSR_IA32_XFD) to set XFD[18] = 1,
and a host IRQ triggers kernel_fpu_begin() prior to the vmexit handler's
call to fpu_update_guest_xfd().
and if userspace stuffs XSTATE_BV[i]=1 via KVM_SET_XSAVE:
------------[ cut here ]------------
WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#14: amx_test/867
Modules linked in: kvm_intel kvm irqbypass
CPU: 14 UID: 1000 PID: 867 Comm: amx_test Not tainted 6.19.0-rc2-2dace9faccd6-x86_amx_nm_xfd_non_init-vm #168 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:exc_device_not_available+0x101/0x110
Call Trace:
<TASK>
asm_exc_device_not_available+0x1a/0x20
RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90
fpu_swap_kvm_fpstate+0x6b/0x120
kvm_load_guest_fpu+0x30/0x80 [kvm]
kvm_arch_vcpu_ioctl_run+0x85/0x1e40 [kvm]
kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm]
__x64_sys_ioctl+0x8f/0xd0
do_syscall_64+0x62/0x940
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
The new behavior is consistent with the AMX architecture. Per Intel's SDM,
XSAVE saves XSTATE_BV as '0' for components that are disabled via XFD
(and non-compacted XSAVE saves the initial configuration of the state
component):
If XSAVE, XSAVEC, XSAVEOPT, or XSAVES is saving the state component i,
the instruction does not generate #NM when XCR0[i] = IA32_XFD[i] = 1;
instead, it operates as if XINUSE[i] = 0 (and the state component was
in its initial state): it saves bit i of XSTATE_BV field of the XSAVE
header as 0; in addition, XSAVE saves the initial configuration of the
state component (the other instructions do not save state component i).
Alternatively, KVM could always do XRSTOR with XFD=0, e.g. by using
a constant XFD based on the set of enabled features when XSAVEing for
a struct fpu_guest. However, having XSTATE_BV[i]=1 for XFD-disabled
features can only happen in the above interrupt case, or in similar
scenarios involving preemption on preemptible kernels, because
fpu_swap_kvm_fpstate()'s call to save_fpregs_to_fpstate() saves the
outgoing FPU state with the current XFD; and that is (on all but the
first WRMSR to XFD) the guest XFD.
Therefore, XFD can only go out of sync with XSTATE_BV in the above
interrupt case, or in similar scenarios involving preemption on
preemptible kernels, and it we can consider it (de facto) part of KVM
ABI that KVM_GET_XSAVE returns XSTATE_BV[i]=0 for XFD-disabled features.
[Move clea
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()
Blamed commit did not take care of VLAN encapsulations
as spotted by syzbot [1].
Use skb_vlan_inet_prepare() instead of pskb_inet_may_pull().
[1]
BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321
__INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321
ip6ip6_dscp_ecn_decapsulate+0x16f/0x1b0 net/ipv6/ip6_tunnel.c:729
__ip6_tnl_rcv+0xed9/0x1b50 net/ipv6/ip6_tunnel.c:860
ip6_tnl_rcv+0xc3/0x100 net/ipv6/ip6_tunnel.c:903
gre_rcv+0x1529/0x1b90 net/ipv6/ip6_gre.c:-1
ip6_protocol_deliver_rcu+0x1c89/0x2c60 net/ipv6/ip6_input.c:438
ip6_input_finish+0x1f4/0x4a0 net/ipv6/ip6_input.c:489
NF_HOOK include/linux/netfilter.h:318 [inline]
ip6_input+0x9c/0x330 net/ipv6/ip6_input.c:500
ip6_mc_input+0x7ca/0xc10 net/ipv6/ip6_input.c:590
dst_input include/net/dst.h:474 [inline]
ip6_rcv_finish+0x958/0x990 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:318 [inline]
ipv6_rcv+0xf1/0x3c0 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core net/core/dev.c:6139 [inline]
__netif_receive_skb+0x1df/0xac0 net/core/dev.c:6252
netif_receive_skb_internal net/core/dev.c:6338 [inline]
netif_receive_skb+0x57/0x630 net/core/dev.c:6397
tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485
tun_get_user+0x5c0e/0x6c60 drivers/net/tun.c:1953
tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0xbe2/0x15d0 fs/read_write.c:686
ksys_write fs/read_write.c:738 [inline]
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:4960 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x9e7/0x17a0 mm/slub.c:5315
kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586
__alloc_skb+0x805/0x1040 net/core/skbuff.c:690
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xc5/0xa60 net/core/skbuff.c:6712
sock_alloc_send_pskb+0xacc/0xc60 net/core/sock.c:2995
tun_alloc_skb drivers/net/tun.c:1461 [inline]
tun_get_user+0x1142/0x6c60 drivers/net/tun.c:1794
tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0xbe2/0x15d0 fs/read_write.c:686
ksys_write fs/read_write.c:738 [inline]
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 0 UID: 0 PID: 6465 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix reference count leak in bpf_prog_test_run_xdp()
syzbot is reporting
unregister_netdevice: waiting for sit0 to become free. Usage count = 2
problem. A debug printk() patch found that a refcount is obtained at
xdp_convert_md_to_buff() from bpf_prog_test_run_xdp().
According to commit ec94670fcb3b ("bpf: Support specifying ingress via
xdp_md context in BPF_PROG_TEST_RUN"), the refcount obtained by
xdp_convert_md_to_buff() will be released by xdp_convert_buff_to_md().
Therefore, we can consider that the error handling path introduced by
commit 1c1949982524 ("bpf: introduce frags support to
bpf_prog_test_run_xdp()") forgot to call xdp_convert_buff_to_md(). |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: return the handler error from mon_handle_auth_done()
Currently any error from ceph_auth_handle_reply_done() is propagated
via finish_auth() but isn't returned from mon_handle_auth_done(). This
results in higher layers learning that (despite the monitor considering
us to be successfully authenticated) something went wrong in the
authentication phase and reacting accordingly, but msgr2 still trying
to proceed with establishing the session in the background. In the
case of secure mode this can trigger a WARN in setup_crypto() and later
lead to a NULL pointer dereference inside of prepare_auth_signature(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: mscc: ocelot: Fix crash when adding interface under a lag
Commit 15faa1f67ab4 ("lan966x: Fix crash when adding interface under a lag")
fixed a similar issue in the lan966x driver caused by a NULL pointer dereference.
The ocelot_set_aggr_pgids() function in the ocelot driver has similar logic
and is susceptible to the same crash.
This issue specifically affects the ocelot_vsc7514.c frontend, which leaves
unused ports as NULL pointers. The felix_vsc9959.c frontend is unaffected as
it uses the DSA framework which registers all ports.
Fix this by checking if the port pointer is valid before accessing it. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: provide locking for v4_end_grace
Writing to v4_end_grace can race with server shutdown and result in
memory being accessed after it was freed - reclaim_str_hashtbl in
particularly.
We cannot hold nfsd_mutex across the nfsd4_end_grace() call as that is
held while client_tracking_op->init() is called and that can wait for
an upcall to nfsdcltrack which can write to v4_end_grace, resulting in a
deadlock.
nfsd4_end_grace() is also called by the landromat work queue and this
doesn't require locking as server shutdown will stop the work and wait
for it before freeing anything that nfsd4_end_grace() might access.
However, we must be sure that writing to v4_end_grace doesn't restart
the work item after shutdown has already waited for it. For this we
add a new flag protected with nn->client_lock. It is set only while it
is safe to make client tracking calls, and v4_end_grace only schedules
work while the flag is set with the spinlock held.
So this patch adds a nfsd_net field "client_tracking_active" which is
set as described. Another field "grace_end_forced", is set when
v4_end_grace is written. After this is set, and providing
client_tracking_active is set, the laundromat is scheduled.
This "grace_end_forced" field bypasses other checks for whether the
grace period has finished.
This resolves a race which can result in use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
net: fix memory leak in skb_segment_list for GRO packets
When skb_segment_list() is called during packet forwarding, it handles
packets that were aggregated by the GRO engine.
Historically, the segmentation logic in skb_segment_list assumes that
individual segments are split from a parent SKB and may need to carry
their own socket memory accounting. Accordingly, the code transfers
truesize from the parent to the newly created segments.
Prior to commit ed4cccef64c1 ("gro: fix ownership transfer"), this
truesize subtraction in skb_segment_list() was valid because fragments
still carry a reference to the original socket.
However, commit ed4cccef64c1 ("gro: fix ownership transfer") changed
this behavior by ensuring that fraglist entries are explicitly
orphaned (skb->sk = NULL) to prevent illegal orphaning later in the
stack. This change meant that the entire socket memory charge remained
with the head SKB, but the corresponding accounting logic in
skb_segment_list() was never updated.
As a result, the current code unconditionally adds each fragment's
truesize to delta_truesize and subtracts it from the parent SKB. Since
the fragments are no longer charged to the socket, this subtraction
results in an effective under-count of memory when the head is freed.
This causes sk_wmem_alloc to remain non-zero, preventing socket
destruction and leading to a persistent memory leak.
The leak can be observed via KMEMLEAK when tearing down the networking
environment:
unreferenced object 0xffff8881e6eb9100 (size 2048):
comm "ping", pid 6720, jiffies 4295492526
backtrace:
kmem_cache_alloc_noprof+0x5c6/0x800
sk_prot_alloc+0x5b/0x220
sk_alloc+0x35/0xa00
inet6_create.part.0+0x303/0x10d0
__sock_create+0x248/0x640
__sys_socket+0x11b/0x1d0
Since skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST
packets constructed by GRO, the truesize adjustment is removed.
The call to skb_release_head_state() must be preserved. As documented in
commit cf673ed0e057 ("net: fix fraglist segmentation reference count
leak"), it is still required to correctly drop references to SKB
extensions that may be overwritten during __copy_skb_header(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: sock: fix hardened usercopy panic in sock_recv_errqueue
skbuff_fclone_cache was created without defining a usercopy region,
[1] unlike skbuff_head_cache which properly whitelists the cb[] field.
[2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is
enabled and the kernel attempts to copy sk_buff.cb data to userspace
via sock_recv_errqueue() -> put_cmsg().
The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone()
(from skbuff_fclone_cache) [1]
2. The skb is cloned via skb_clone() using the pre-allocated fclone
[3] 3. The cloned skb is queued to sk_error_queue for timestamp
reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE)
5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb
[4] 6. __check_heap_object() fails because skbuff_fclone_cache has no
usercopy whitelist [5]
When cloned skbs allocated from skbuff_fclone_cache are used in the
socket error queue, accessing the sock_exterr_skb structure in skb->cb
via put_cmsg() triggers a usercopy hardening violation:
[ 5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)!
[ 5.382796] kernel BUG at mm/usercopy.c:102!
[ 5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
[ 5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 #7
[ 5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 5.384903] RIP: 0010:usercopy_abort+0x6c/0x80
[ 5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490
[ 5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246
[ 5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74
[ 5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0
[ 5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74
[ 5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001
[ 5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00
[ 5.384903] FS: 0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000
[ 5.384903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0
[ 5.384903] PKRU: 55555554
[ 5.384903] Call Trace:
[ 5.384903] <TASK>
[ 5.384903] __check_heap_object+0x9a/0xd0
[ 5.384903] __check_object_size+0x46c/0x690
[ 5.384903] put_cmsg+0x129/0x5e0
[ 5.384903] sock_recv_errqueue+0x22f/0x380
[ 5.384903] tls_sw_recvmsg+0x7ed/0x1960
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
[ 5.384903] ? schedule+0x6d/0x270
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
[ 5.384903] ? mutex_unlock+0x81/0xd0
[ 5.384903] ? __pfx_mutex_unlock+0x10/0x10
[ 5.384903] ? __pfx_tls_sw_recvmsg+0x10/0x10
[ 5.384903] ? _raw_spin_lock_irqsave+0x8f/0xf0
[ 5.384903] ? _raw_read_unlock_irqrestore+0x20/0x40
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
The crash offset 296 corresponds to skb2->cb within skbuff_fclones:
- sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 -
offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 =
272 + 24 (inside sock_exterr_skb.ee)
This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure.
[1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885
[2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104
[3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566
[4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491
[5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719 |
