In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tvlv: reject oversized TVLV packets
batadv_tvlv_container_ogm_append() builds a TVLV packet section from
the tvlv.container_list. The total size of this section is computed by
batadv_tvlv_container_list_size(), which sums the sizes of all registered
containers.
The return type and accumulator in batadv_tvlv_container_list_size() were
u16. If the accumulated size exceeds U16_MAX, the value wraps around,
causing the subsequent allocation in batadv_tvlv_container_ogm_append()
to be undersized. The memcpy-style copy that follows would then write
beyond the end of the allocated buffer, corrupting kernel memory.
Fix this by widening the return type of batadv_tvlv_container_list_size()
to size_t. In batadv_tvlv_container_ogm_append(), check the computed length
against U16_MAX before proceeding, and bail out as if the allocation had
failed when the limit is exceeded.
In the Linux kernel, the following vulnerability has been resolved:
xfrm: espintcp: do not reuse an in-progress partial send
espintcp keeps a single in-flight transmit in ctx->partial.
Before building a new sk_msg, espintcp_sendmsg() first tries to flush
that state through espintcp_push_msgs().
For blocking callers, espintcp_push_msgs() may return success even when
the previous partial send is still pending. espintcp_sendmsg() would
then reinitialize emsg->skmsg and reuse ctx->partial while the old
transfer still owns that state.
Do not rebuild the send message when ctx->partial is still in progress.
If espintcp_push_msgs() returns with emsg->len still set, fail the new
send instead of overwriting the live partial state.
This is a memory-safety fix: reusing the live partial-send state can
leave a stale offset attached to a new sk_msg and lead to an out-of-
bounds read in the send path.
tcp_sendmsg_locked() already handles waiting for send buffer memory, so
the fix here is just to preserve espintcp's one-message-at-a-time
transmit state.
In the Linux kernel, the following vulnerability has been resolved:
crypto: jitterentropy - replace long-held spinlock with mutex
jent_kcapi_random() serializes the shared jitterentropy state, but it
currently holds a spinlock across the jent_read_entropy() call. That
path performs expensive jitter collection and SHA3 conditioning, so
parallel readers can trigger stalls as contending waiters spin for
the same lock.
To prevent non-preemptible lock hold, replace rng->jent_lock with a
mutex so contended readers sleep instead of spinning on a shared lock
held across expensive entropy generation.
In the Linux kernel, the following vulnerability has been resolved:
tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR
In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an
uninitialised on-stack struct sockaddr_storage to userspace via
ifr_hwaddr, but netif_get_mac_address() only writes sa_family and
dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised.
Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a
macvtap chardev returns kernel .text and direct-map pointers, defeating
KASLR.
Initialise ss at declaration.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: stop hash:* range iteration at end
The following hash set variants:
hash:ip,mark
hash:ip,port
hash:ip,port,ip
hash:ip,port,net
iterate IPv4 ranges with a 32-bit iterator.
The iterator must stop once the last address in the requested range has
been processed. Advancing it once more can move the traversal state past
the end of the request, so a later retry may continue from an unintended
position.
Handle the iterator increment explicitly at the end of the loop and stop
once the upper bound has been processed. This keeps the existing retry
behaviour intact for valid ranges while preventing traversal from
continuing past the original boundary.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: dat: handle forward allocation error
batadv_dat_forward_data() calls pskb_copy_for_clone() to duplicate an skb
for each DHT candidate, but does not check the return value before passing
it to batadv_send_skb_prepare_unicast_4addr(). That function dereferences
the skb unconditionally, so a failed allocation triggers a NULL pointer
dereference.
Skip forwarding to the current DHT candidate on allocation failure.
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:
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:
vrf: Fix a potential NPD when removing a port from a VRF
RCU readers that identified a net device as a VRF port using
netif_is_l3_slave() assume that a subsequent call to
netdev_master_upper_dev_get_rcu() will return a VRF device. They then
continue to dereference its l3mdev operations.
This assumption is not always correct and can result in a NPD [1]. There
is no RCU synchronization when removing a port from a VRF, so it is
possible for an RCU reader to see a new master device (e.g., a bridge)
that does not have l3mdev operations.
Fix by adding RCU synchronization after clearing the IFF_L3MDEV_SLAVE
flag. Skip this synchronization when a net device is removed from a VRF
as part of its deletion and when the VRF device itself is deleted. In
the latter case an RCU grace period will pass by the time RTNL is
released.
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
RIP: 0010:l3mdev_fib_table_rcu (net/l3mdev/l3mdev.c:181)
[...]
Call Trace:
<TASK>
l3mdev_fib_table_by_index (net/l3mdev/l3mdev.c:201 net/l3mdev/l3mdev.c:189)
__inet_bind (net/ipv4/af_inet.c:499 (discriminator 3))
inet_bind_sk (net/ipv4/af_inet.c:469)
__sys_bind (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:1951 (discriminator 1))
__x64_sys_bind (net/socket.c:1969 (discriminator 1) net/socket.c:1967 (discriminator 1) net/socket.c:1967 (discriminator 1))
do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: clear current gateway during teardown
batadv_gw_node_free() removes the gateway list entries during mesh teardown,
but it does not clear the currently selected gateway. This leaves stale
gateway state behind across cleanup and can break a later mesh recreation.
Clear bat_priv->gw.curr_gw before walking the gateway list so the selected
gateway reference is dropped as part of teardown.