| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: free preauth sessions on connection teardown
SMB3.1.1 multichannel binding preserves the preauthentication hash in a
preauth_session between the NTLM negotiate and authenticate requests.
The binding NTLM negotiate allocates this object and returns
STATUS_MORE_PROCESSING_REQUIRED. If the client disconnects before it sends
the authenticate request, neither the authenticate nor error cleanup paths
free the object.
Release any remaining preauthentication sessions when tearing down the
connection. Initialize the list when allocating the connection so that this
cleanup is safe regardless of the negotiated dialect. |
| In the Linux kernel, the following vulnerability has been resolved:
vsock: don't check the listener's sk_err in vsock_accept()
Syzbot reported an issue which can be reproduced with these steps:
r0 = socket(AF_VSOCK, SOCK_STREAM, 0)
bind(r0, {VMADDR_CID_ANY, PORT})
connect(r0, {VMADDR_CID_LOCAL, PORT}) -> -1, EPROTO (self-connect)
listen(r0, backlog) -> 0
r1 = socket(AF_VSOCK, SOCK_STREAM, 0)
connect(r1, {VMADDR_CID_LOCAL, PORT}) -> 0
accept(r0) -> -1, EPROTO (stale sk_err)
Basically, it creates a socket (r0) and triggers a self-connect after
binding it. This self-connect fails with EPROTO because it loops back
to r0 while the socket is still in the TCP_SYN_SENT state, causing it
to be incorrectly dispatched to the connecting-client path. The
unexpected packet type encountered there sets sk_err to EPROTO.
After that, it invokes a listen() call on the same socket. This
listen() call succeeds because the kernel's listening path never
inspects or clears sk_err. Then, a new socket (r1) is created as a
normal client and connects to r0. However, vsock_accept() rejects this
incoming connection because the listener's sk_err still holds the
EPROTO error from the earlier failed self-connect.
This rejection causes the child socket created for r1's connection to
never be freed on virtio or hyperv transports; only the VMCI transport
implements pending_work to revisit and clean up a rejected socket.
For a non-blocking connect(), vsock_connect() may return -EINPROGRESS
immediately, and vsock_connect_timeout() can later set sk->sk_err
asynchronously.
Since no vsock transport ever sets sk_err on a socket while it is in
TCP_LISTEN state, checking it in vsock_accept() serves no purpose and
only carries forward errors left behind by earlier, unrelated
connection attempts on the same socket. Remove the checks so accept()
no longer rejects valid incoming connections because of a stale
error, which also avoids the resource leak described above. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix request buffer leak in smb2_new_read_req()
smb2_new_read_req() allocates the request buffer with
smb2_plain_req_init() but only publishes it to the caller with
*buf = req at the very end of the function. Two error returns sit in
between:
rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, server,
(void **) &req, total_len);
if (rc)
return rc;
if (server == NULL)
return -ECONNABORTED;
[...]
rdata->mr = smbd_register_mr(server->smbd_conn,
&rdata->subreq.io_iter,
true, need_invalidate);
if (!rdata->mr)
return -EAGAIN;
On either of them the buffer is neither released nor handed back, so
it is leaked. The caller cannot clean up after it: smb2_async_readv()
does 'goto out' on a non-zero return, which skips the
cifs_small_buf_release(buf) at async_readv_out, and buf has not been
assigned at that point in any case.
The write path has never had this problem. smb2_async_writev()
registers the memory region inline and jumps to its release label
instead of returning:
wdata->mr = smbd_register_mr(...);
if (!wdata->mr) {
rc = -EAGAIN;
goto async_writev_out;
}
Commit b7972092199f ("cifs: smbd: Retry on memory registration
failure") changed both sides from -ENOBUFS to -EAGAIN in a single
patch, which puts the two shapes next to each other.
Only the -EAGAIN return is reachable in practice, because
smb2_plain_req_init() calls smb2_reconnect() first and that already
fails with -EIO when server is NULL, before anything is allocated.
Both returns are given the same treatment here rather than leaving
one of them correct only by accident.
Because -EAGAIN is a replayable error, the failure also reaches the
retry block at the end of smb2_async_readv(), which marks the
subrequest NETFS_SREQ_NEED_RETRY, so a failing registration can be
retried rather than ending the I/O, and every attempt that reaches it
leaks another buffer. smb2_should_replay() short-circuits on
tcon->retry, so on a hard mount the attempt count is not bounded by
the retrans setting.
Only the asynchronous read path is affected. The synchronous
SMB2_read() caller passes rdata == NULL and the memory registration
block is guarded on rdata.
The memory registration failure path was pointed out by the Sashiko
AI reviewer while it was reviewing an unrelated patch to
smb2_async_readv(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: account classifier filter allocations to memcg
Allocations in the tc classifier *_change() paths (filter objects,
per-CPU counters, and per-filter aux data) use plain GFP_KERNEL without
__GFP_ACCOUNT, allowing unprivileged users to pin kernel memory outside
memcg charging. The shared tcf_exts_init_ex() action array allocation in
cls_api.c was also uncharged; this patch closes it along with the
per-classifier filter-object/percpu/aux allocations that remain
unaccounted.
Add GFP_KERNEL_ACCOUNT to:
- the shared tcf_exts_init_ex() action array (cls_api.c), common to every
filter of every classifier (32 pointers, 256 bytes);
- the filter-object, per-CPU-counter, and per-filter aux allocations in
cls_basic, cls_bpf, cls_cgroup, cls_flow, cls_flower, cls_fw,
cls_matchall, cls_route and cls_u32;
- the u32_init_knode() replace-path knode allocation (cls_u32.c), which
allocates the same struct tc_u_knode + sel.keys on every replace of an
existing knode and was missed by the create-path-only conversion.
Also fix the cls_basic error path: basic_change() inserts fnew into the
IDR before allocating the per-CPU counter. If alloc_percpu() fails the
errout path kfree'd fnew without idr_remove, leaving a dangling pointer
in the IDR. With GFP_KERNEL_ACCOUNT the percpu alloc becomes failable
on demand (memcg at memory.max), making the dead path attacker-reachable
and burning the handle permanently. Add the idr_remove on the percpu
failure path, matching the basic_set_parms failure-path pattern.
Note: vega@nebusec.ai provided a poc for basic_cls, but it was easy to
extend to the other classifiers.
Conditions to recreate the bug:
- CONFIG_NET_SCHED, CONFIG_NET_CLS_* (the classifier being used),
CONFIG_NET_CLS_ACT, CONFIG_MEMCG, CONFIG_USER_NS, CONFIG_NET_NS.
- Unprivileged user in a fresh user+network namespace (unshare -Urn),
or root with CAP_NET_ADMIN.
- Create a large number of tc filters (e.g. tc filter add dev lo
ingress ... <classifier> ...) while watching a memcg-limited cgroup:
system slab grows far faster than memory.current, pinning kernel
memory outside memcg charging. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: light: ltrf216a: fix runtime PM reference leak in error path
ltrf216a_get_lux() acquires a runtime PM reference by calling
ltrf216a_set_power_state(data, true). However, if
ltrf216a_read_data() fails, the function returns immediately without
dropping the reference.
This leaves the runtime PM usage count unbalanced, preventing the device
from autosuspending after a failed read.
Fix this by releasing the runtime PM reference before returning from the
error path. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: force complete the KIQ ring fences on reset
Like the MES scheduler ring, the KIQ ring sets no_scheduler = true and uses a
polling fence, so it is skipped by the force-completion loop in
amdgpu_device_pre_asic_reset(). Its hw fence value lives in wb (GTT) memory and
survives a MODE1 reset while fence_drv.sync_seq keeps advancing, so after a
reset the first KIQ submission can poll forever on a seq that is never written
back.
Force complete the KIQ ring fences too so their hw fence is realigned to
sync_seq. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: avoid busy looping in tipc_exit_net()
Blamed commit introduced a busy-wait loop in tipc_exit_net()
to wait for pending UDP bearer cleanup works to complete:
while (atomic_read(&tn->wq_count))
cond_resched();
This loop can busy-wait for a long time if cond_resched() is a NOP. This
typically happens if the netns exit is executed by a high priority task,
or under kernels configured without preemption (CONFIG_PREEMPT_NONE). In
such cases, it wastes CPU cycles and can lead to soft lockups.
Fix this by replacing the busy loop with wait_var_event(), allowing the
thread to sleep properly until the work queue count reaches zero.
Accordingly, update cleanup_bearer() to use atomic_dec_and_test() and
wake_up_var() to wake up the waiter when the count drops to zero.
This uses the global wait queue hash table, avoiding the need to bloat
struct tipc_net with a wait_queue_head_t. The atomic_dec_and_test()
provides the necessary memory barrier to ensure the wakeup is not missed. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: fix invalidate lock leak on setattr writeback failure
fuse_do_setattr() takes filemap_invalidate_lock() for a DAX truncate
(fault_blocked = true) and releases it at the out:/error: labels. But
when a writeback flush is also needed, a write_inode_now() failure
returns directly and leaks the lock, so any later fault or truncate on
the file stalls on the stale rwsem.
For example, truncate(2) on a setuid file reaches fuse_do_setattr()
with both ATTR_SIZE and ATTR_MODE set:
truncate(2)
└─ do_truncate()
├─ dentry_needs_remove_privs() # S_ISUID
└─ notify_change() # KILL_SUID -> ATTR_MODE
└─ fuse_setattr() # no killpriv:
│ # ia_valid |= ATTR_MODE
└─ fuse_do_setattr()
├─ filemap_invalidate_lock() # IS_DAX && is_truncate
└─ write_inode_now() # is_wb && ATTR_MODE
└─ if (err) # e.g. daemon -> -EIO
return err # <- lock leaked
Fix this by adding an unlock label that releases the lock before
returning the error, and use it for the fuse_dax_break_layouts()
failure path as well. |
| In the Linux kernel, the following vulnerability has been resolved:
IB/mlx5: Fix transport-domain rollback and initialize lb mutex earlier
mlx5_ib_alloc_transport_domain() allocates a transport domain and then
may fail in mlx5_ib_enable_lb(). In that case, the allocated TD is leaked.
Fix this by deallocating the TD when mlx5_ib_enable_lb() returns an
error. Also return 0 explicitly in the no-loopback-capability success
branch, and move dev->lb.mutex initialization to mlx5_ib_stage_init_init(). |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpci_rt1711h: unregister TCPCI port with devres
rt1711h_probe() registers the TCPCI port before requesting the interrupt
and enabling alert interrupts. If either of those later steps fails, the
probe function returns without unregistering the TCPCI port. The explicit
unregister currently only happens from the remove callback.
Register a devres action immediately after tcpci_register_port() succeeds,
so tcpci_unregister_port() runs on later probe failures and on driver
detach. Drop the remove callback to avoid unregistering the same port
twice.
This issue was identified during our ongoing static-analysis research while
reviewing kernel code. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close
Since hci_dev_close_sync() can now be called during the reset path, we
should also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts
while the hdev workqueue is being drained. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: xsk: Fix DMA and xdp_frame leak on XDP_TX xmit failure
In the XSK branch of mlx5e_xmit_xdp_buff(), when sq->xmit_xdp_frame()
returns false (e.g. XDPSQ is full), the function returns without
unmapping the DMA address or freeing the xdp_frame allocated by
xdp_convert_zc_to_xdp_frame(). The xdpi_fifo push only happens on
success, so the completion path cannot recover these entries.
With CONFIG_DMA_API_DEBUG=y, the leak surfaces on driver unbind:
DMA-API: pci 0000:08:00.0: device driver has pending DMA
allocations while released from device [count=1116]
One of leaked entries details: [device address=0x000000010ffd7028]
[size=1534 bytes] [mapped with DMA_TO_DEVICE] [mapped as phy]
WARNING: kernel/dma/debug.c:881 at dma_debug_device_change+0x127/0x180
...
DMA-API: Mapped at:
debug_dma_map_phys+0x4b/0xd0
dma_map_phys+0xfd/0x2d0
mlx5e_xdp_handle+0x5ae/0xac0 [mlx5_core]
mlx5e_xsk_skb_from_cqe_mpwrq_linear+0xc4/0x170 [mlx5_core]
mlx5e_handle_rx_cqe_mpwrq+0xc1/0x290 [mlx5_core]
Add the missing unmap + xdp_return_frame, matching the cleanup already
done in mlx5e_xdp_xmit(). has_frags is rejected earlier in this branch,
so no per-frag unmap is needed. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation
Ulrich reports a regression with nfqueue:
If an application did not set the 'F_GSO' capability flag and a gso
packet with an unconfirmed nf_conn entry is received all packets are
now dropped instead of queued, because the check happens after
skb_gso_segment(). In that case, we did have exclusive ownership
of the skb and its associated conntrack entry. The elevated use
count is due to skb_clone happening via skb_gso_segment().
Move the check so that its peformed vs. the aggregated packet.
Then, annotate the individual segments except the first one so we
can do a 2nd check at reinject time.
For the normal case, where userspace does in-order reinjects, this avoids
packet drops: first reinjected segment continues traversal and confirms
entry, remaining segments observe the confirmed entry.
While at it, simplify nf_ct_drop_unconfirmed(): We only care about
unconfirmed entries with a refcnt > 1, there is no need to special-case
dying entries.
This only happens with UDP. With TCP, the only unconfirmed packet will
be the TCP SYN, those aren't aggregated by GRO.
Next patch adds a udpgro test case to cover this scenario. |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: fix zero-frag skb in frag_list on partial sendmsg error
Syzkaller reported a warning in kcm_write_msgs() when processing a
message with a zero-fragment skb in the frag_list.
When kcm_sendmsg() fills MAX_SKB_FRAGS fragments in the current skb,
it allocates a new skb (tskb) and links it into the frag_list before
copying data. If the copy subsequently fails (e.g. -EFAULT from
user memory), tskb remains in the frag_list with zero fragments:
head skb (msg being assembled, NOT yet in sk_write_queue)
+-----------+
| frags[17] | (MAX_SKB_FRAGS, all filled with data)
| frag_list-+--> tskb
+-----------+ +----------+
| frags[0] | (empty! copy failed before filling)
+----------+
For SOCK_SEQPACKET with partial data already copied, the error path
saves this message via partial_message for later completion. For
SOCK_SEQPACKET, sock_write_iter() automatically sets MSG_EOR, so a
subsequent zero-length write(fd, NULL, 0) completes the message and
queues it to sk_write_queue. kcm_write_msgs() then walks the
frag_list and hits:
WARN_ON(!skb_shinfo(skb)->nr_frags)
TCP has a similar pattern where skbs are enqueued before data copy
and cleaned up on failure via tcp_remove_empty_skb(). KCM was
missing the equivalent cleanup.
Fix this by tracking the predecessor skb (frag_prev) when allocating
a new frag_list entry. On error, if the tail skb has zero frags,
use frag_prev to unlink and free it in O(1) without walking the
singly-linked frag_list. frag_prev is safe to dereference because
the entire message chain is only held locally (or in kcm->seq_skb)
and is not added to sk_write_queue until MSG_EOR, so the send path
cannot free it underneath us.
Also change the WARN_ON to WARN_ON_ONCE to avoid flooding the log
if the condition is somehow hit repeatedly.
There are currently no KCM selftests in the kernel tree; a simple
reproducer is available at [1].
[1] https://gist.github.com/mrpre/a94d431c757e8d6f168f4dd1a3749daa |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: complete pending data exchange on device close
In nci_close_device(), complete any pending data exchange before
closing. The data exchange callback (e.g.
rawsock_data_exchange_complete) holds a socket reference.
NIPA occasionally hits this leak:
unreferenced object 0xff1100000f435000 (size 2048):
comm "nci_dev", pid 3954, jiffies 4295441245
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
27 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00 '..@............
backtrace (crc ec2b3c5):
__kmalloc_noprof+0x4db/0x730
sk_prot_alloc.isra.0+0xe4/0x1d0
sk_alloc+0x36/0x760
rawsock_create+0xd1/0x540
nfc_sock_create+0x11f/0x280
__sock_create+0x22d/0x630
__sys_socket+0x115/0x1d0
__x64_sys_socket+0x72/0xd0
do_syscall_64+0x117/0xfc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53 |
| In the Linux kernel, the following vulnerability has been resolved:
of: unittest: Fix memory leak in unittest_data_add()
In unittest_data_add(), if of_resolve_phandles() fails, the allocated
unittest_data is not freed, leading to a memory leak.
Fix this by using scope-based cleanup helper __free(kfree) for automatic
resource cleanup. This ensures unittest_data is automatically freed when
it goes out of scope in error paths.
For the success path, use retain_and_null_ptr() to transfer ownership
of the memory to the device tree and prevent double freeing. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix xmit_frame/xmit_buf leaks on mgnt-frame error paths
issue_beacon(), issue_probersp() and issue_asocrsp() obtain a management
xmit_frame together with its xmit_buf from the driver's fixed-size
management-TX pools via alloc_mgtxmitframe(). On the normal path the frame
is handed to dump_mgntframe(), which transfers ownership and eventually
returns both objects to their pools (the frame and, for beacons, the buf
in rtl8723bs_mgnt_xmit(); other bufs via the pending-xmitbuf/TX-completion
path).
Several error/edge paths return early after a successful
alloc_mgtxmitframe() but before dump_mgntframe(), so ownership is never
transferred and neither object is freed:
- issue_beacon(): beacon larger than 512 bytes
- issue_probersp(): cur_network->ie_length > MAX_IE_SZ
- issue_probersp(): kzalloc() of the SSID scratch buffer fails
- issue_asocrsp(): pkt_type is neither ASSOCRSP nor REASSOCRSP
Because alloc_mgtxmitframe() removes the frame and buf from their free
lists (list_del_init) without placing them on any pending list, an
orphaned pair is on no list and referenced by nobody, so it is only
reclaimed at driver teardown. Repeated hits progressively exhaust the
management-TX pools until alloc_mgtxmitframe() returns NULL and the
interface can no longer send beacons or probe/assoc responses.
Free the frame and buffer on these paths, matching the existing correct
error handling in issue_assocreq(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Remove skb secpath if xfrm state is not found
Hardware returns a unique identifier for a decrypted packet's xfrm
state, this state is looked up in an xarray. However, the state might
have been freed by the time of this lookup.
Currently, if the state is not found, only a counter is incremented.
The secpath (sp) extension on the skb is not removed, resulting in
sp->len becoming 0.
Subsequently, functions like __xfrm_policy_check() attempt to access
fields such as xfrm_input_state(skb)->xso.type (which dereferences
sp->xvec[sp->len - 1]) without first validating sp->len. This leads to
a crash when dereferencing an invalid state pointer.
This patch prevents the crash by explicitly removing the secpath
extension from the skb if the xfrm state is not found after hardware
decryption. This ensures downstream functions do not operate on a
zero-length secpath.
BUG: unable to handle page fault for address: ffffffff000002c8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 282e067 P4D 282e067 PUD 0
Oops: Oops: 0000 [#1] SMP
CPU: 12 UID: 0 PID: 0 Comm: swapper/12 Not tainted 6.15.0-rc7_for_upstream_min_debug_2025_05_27_22_44 #1 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:__xfrm_policy_check+0x61a/0xa30
Code: b6 77 7f 83 e6 02 74 14 4d 8b af d8 00 00 00 41 0f b6 45 05 c1 e0 03 48 98 49 01 c5 41 8b 45 00 83 e8 01 48 98 49 8b 44 c5 10 <0f> b6 80 c8 02 00 00 83 e0 0c 3c 04 0f 84 0c 02 00 00 31 ff 80 fa
RSP: 0018:ffff88885fb04918 EFLAGS: 00010297
RAX: ffffffff00000000 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffffff8311af80 R08: 0000000000000020 R09: 00000000c2eda353
R10: ffff88812be2bbc8 R11: 000000001faab533 R12: ffff88885fb049c8
R13: ffff88812be2bbc8 R14: 0000000000000000 R15: ffff88811896ae00
FS: 0000000000000000(0000) GS:ffff8888dca82000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff000002c8 CR3: 0000000243050002 CR4: 0000000000372eb0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
? try_to_wake_up+0x108/0x4c0
? udp4_lib_lookup2+0xbe/0x150
? udp_lib_lport_inuse+0x100/0x100
? __udp4_lib_lookup+0x2b0/0x410
__xfrm_policy_check2.constprop.0+0x11e/0x130
udp_queue_rcv_one_skb+0x1d/0x530
udp_unicast_rcv_skb+0x76/0x90
__udp4_lib_rcv+0xa64/0xe90
ip_protocol_deliver_rcu+0x20/0x130
ip_local_deliver_finish+0x75/0xa0
ip_local_deliver+0xc1/0xd0
? ip_protocol_deliver_rcu+0x130/0x130
ip_sublist_rcv+0x1f9/0x240
? ip_rcv_finish_core+0x430/0x430
ip_list_rcv+0xfc/0x130
__netif_receive_skb_list_core+0x181/0x1e0
netif_receive_skb_list_internal+0x200/0x360
? mlx5e_build_rx_skb+0x1bc/0xda0 [mlx5_core]
gro_receive_skb+0xfd/0x210
mlx5e_handle_rx_cqe_mpwrq+0x141/0x280 [mlx5_core]
mlx5e_poll_rx_cq+0xcc/0x8e0 [mlx5_core]
? mlx5e_handle_rx_dim+0x91/0xd0 [mlx5_core]
mlx5e_napi_poll+0x114/0xab0 [mlx5_core]
__napi_poll+0x25/0x170
net_rx_action+0x32d/0x3a0
? mlx5_eq_comp_int+0x8d/0x280 [mlx5_core]
? notifier_call_chain+0x33/0xa0
handle_softirqs+0xda/0x250
irq_exit_rcu+0x6d/0xc0
common_interrupt+0x81/0xa0
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
ax25: Remove broken autobind
Binding AX25 socket by using the autobind feature leads to memory leaks
in ax25_connect() and also refcount leaks in ax25_release(). Memory
leak was detected with kmemleak:
================================================================
unreferenced object 0xffff8880253cd680 (size 96):
backtrace:
__kmalloc_node_track_caller_noprof (./include/linux/kmemleak.h:43)
kmemdup_noprof (mm/util.c:136)
ax25_rt_autobind (net/ax25/ax25_route.c:428)
ax25_connect (net/ax25/af_ax25.c:1282)
__sys_connect_file (net/socket.c:2045)
__sys_connect (net/socket.c:2064)
__x64_sys_connect (net/socket.c:2067)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
================================================================
When socket is bound, refcounts must be incremented the way it is done
in ax25_bind() and ax25_setsockopt() (SO_BINDTODEVICE). In case of
autobind, the refcounts are not incremented.
This bug leads to the following issue reported by Syzkaller:
================================================================
ax25_connect(): syz-executor318 uses autobind, please contact jreuter@yaina.de
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 5317 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz-executor318 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
...
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:336 [inline]
refcount_dec include/linux/refcount.h:351 [inline]
ref_tracker_free+0x6af/0x7e0 lib/ref_tracker.c:236
netdev_tracker_free include/linux/netdevice.h:4302 [inline]
netdev_put include/linux/netdevice.h:4319 [inline]
ax25_release+0x368/0x960 net/ax25/af_ax25.c:1080
__sock_release net/socket.c:647 [inline]
sock_close+0xbc/0x240 net/socket.c:1398
__fput+0x3e9/0x9f0 fs/file_table.c:464
__do_sys_close fs/open.c:1580 [inline]
__se_sys_close fs/open.c:1565 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1565
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
</TASK>
================================================================
Considering the issues above and the comments left in the code that say:
"check if we can remove this feature. It is broken."; "autobinding in this
may or may not work"; - it is better to completely remove this feature than
to fix it because it is broken and leads to various kinds of memory bugs.
Now calling connect() without first binding socket will result in an
error (-EINVAL). Userspace software that relies on the autobind feature
might get broken. However, this feature does not seem widely used with
this specific driver as it was not reliable at any point of time, and it
is already broken anyway. E.g. ax25-tools and ax25-apps packages for
popular distributions do not use the autobind feature for AF_AX25.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mctp: unshare packets when reassembling
Ensure that the frag_list used for reassembly isn't shared with other
packets. This avoids incorrect reassembly when packets are cloned, and
prevents a memory leak due to circular references between fragments and
their skb_shared_info.
The upcoming MCTP-over-USB driver uses skb_clone which can trigger the
problem - other MCTP drivers don't share SKBs.
A kunit test is added to reproduce the issue. |
