In the Linux kernel, the following vulnerability has been resolved:
net: guard timestamp cmsgs to real error queue skbs
skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb
from sk_error_queue. That assumption is not true for AF_PACKET sockets:
outgoing packet taps are also delivered to packet sockets with
skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET
instead of struct sock_exterr_skb.
If such an skb is received with timestamping enabled, the generic
timestamp cmsg path can read AF_PACKET control-buffer state as
sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop
counter overlaps opt_stats. An odd drop count makes the path emit
SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear
skbs this copies past the linear head and can trigger hardened usercopy or
disclose adjacent heap contents.
Keep skb_is_err_queue() local to net/socket.c, but make it verify that
the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor
installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal
receive ownership and no longer pass as error-queue skbs, while legitimate
sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free
ownership.
In the Linux kernel, the following vulnerability has been resolved:
sctp: validate embedded INIT chunk and address list lengths in cookie
sctp_unpack_cookie() only checked that the embedded INIT chunk length
did not exceed the remaining cookie payload, but did not ensure that the
INIT chunk is large enough to contain a complete INIT header.
A malformed COOKIE_ECHO can therefore carry a truncated INIT chunk whose
length field is smaller than sizeof(struct sctp_init_chunk). Later,
sctp_process_init() accesses INIT parameters unconditionally, which may
lead to out-of-bounds reads.
In addition, raw_addr_list_len is not fully validated against the
remaining cookie payload. When cookie authentication is disabled, an
attacker can supply an oversized raw_addr_list_len and cause
sctp_raw_to_bind_addrs() to read beyond the end of the cookie. The
address parser also lacks sufficient bounds checks for parameter headers
and lengths, allowing malformed address parameters to trigger
out-of-bounds reads.
Fix this by:
- requiring the embedded INIT chunk length to be at least sizeof(struct
sctp_init_chunk);
- validating that the INIT chunk and raw address list together fit
within the cookie payload;
- verifying sufficient data exists for each address parameter header and
payload before parsing it.
Note that sctp_verify_init() must be called after sctp_unpack_cookie()
and before sctp_process_init() when cookie authentication is disabled.
This will be addressed in a separate patch.
In the Linux kernel, the following vulnerability has been resolved:
sctp: fix uninit-value in __sctp_rcv_asconf_lookup()
__sctp_rcv_asconf_lookup() in net/sctp/input.c only checks that the ASCONF
chunk can hold the ADDIP header and a parameter header, then calls
af->from_addr_param(), which reads the full address (16 bytes for IPv6)
trusting the parameter's declared length.
An unauthenticated peer can send a truncated trailing ASCONF chunk that
declares an IPv6 address parameter but stops after the 4-byte parameter
header; reached from the no-association lookup path, from_addr_param() then
reads uninitialized bytes past the parameter.
Impact: an unauthenticated SCTP peer makes the receive path read up to 16
bytes of uninitialized memory past a truncated ASCONF address parameter.
The sibling __sctp_rcv_init_lookup() bounds parameters with
sctp_walk_params(); this path open-codes the fetch and omits the bound.
Verify the whole address parameter lies within the chunk before
from_addr_param() reads it, the same class of fix as commit 51e5ad549c43
("net: sctp: fix KMSAN uninit-value in sctp_inq_pop").
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix possible kfree_skb of ERR_PTR
After the patch in the "Fixes" tag, the allocation of the "reply" skb
can happen either before or after locking the ovs_mutex.
However, error cleanups still follow the classical reversed order,
assuming "reply" is allocated before locking: it is freed after unlocking.
If "reply" allocation happens after locking the mutex and it fails,
"reply" is left with an ERR_PTR, and execution jumps to the correspondent
cleanup stage which will try to free an invalid pointer.
Fix this by setting the pointer to NULL after having saved its error
value.
In the Linux kernel, the following vulnerability has been resolved:
ipv6: sit: reload inner IPv6 header after GSO offloads
ipip6_tunnel_xmit() caches the inner IPv6 header pointer at function
entry and continues using it after iptunnel_handle_offloads().
For GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone().
When the skb header is cloned, skb_header_unclone() can call
pskb_expand_head(), which may move the skb head. The pskb_expand_head()
contract requires pointers into the skb header to be reloaded after the
call.
If the later skb_realloc_headroom() branch is not taken, SIT uses the
stale iph6 pointer to read the inner hop limit and DS field. That can
read from a freed skb head after the old head's remaining clone is
released.
Reload iph6 after the offload helper succeeds and before subsequent
reads from the inner IPv6 header. Keep the existing reload after
skb_realloc_headroom(), since that branch can also replace the skb.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix slab-out-of-bounds in mlx5_query_nic_vport_mac_list
mlx5_query_nic_vport_mac_list() sizes its firmware command buffer using
the PF's log_max_current_uc/mc_list capabilities. When querying a VF
vport with a larger configured max (via devlink), the firmware response
can overflow this buffer:
BUG: KASAN: slab-out-of-bounds in mlx5_query_nic_vport_mac_list+0x453/0x4c0 [mlx5_core]
Read of size 4 at addr ff1100013ffc8a12 by task kworker/u96:2/385
CPU: 12 UID: 0 PID: 385 Comm: kworker/u96:2 Not tainted 7.0.0-rc6+ #1 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
Workqueue: mlx5_esw_wq esw_vport_change_handler [mlx5_core]
Call Trace:
<TASK>
dump_stack_lvl+0x69/0xa0
print_report+0x176/0x4e4
kasan_report+0xc8/0x100
mlx5_query_nic_vport_mac_list+0x453/0x4c0 [mlx5_core]
esw_update_vport_addr_list+0x2e3/0xda0 [mlx5_core]
esw_vport_change_handle_locked+0xa1f/0x1060 [mlx5_core]
esw_vport_change_handler+0x6a/0x90 [mlx5_core]
process_one_work+0x87f/0x15e0
worker_thread+0x62b/0x1020
kthread+0x375/0x490
ret_from_fork+0x4dc/0x810
ret_from_fork_asm+0x11/0x20
</TASK>
Fix by querying the vport's own HCA caps to size the buffer correctly.
Refactor the function to allocate and return the MAC list internally,
removing the caller's dependency on knowing the correct max.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_exthdr: fix register tracking for F_PRESENT flag
nft_exthdr_init() passes user-controlled priv->len to
nft_parse_register_store(), which marks that many bytes in the
register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT
is set, the eval paths write only 1 byte (nft_reg_store8) or
4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4,
registers beyond the first are never written, retaining
uninitialized stack data from nft_regs.
Bail out if userspace requests too much data when F_PRESENT is set.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: avoid leaking percpu counter pointers
The native and compat get-entries paths copy the fixed rule entry header
from the kernelized rule blob to userspace before overwriting the entry's
counter fields with a sanitized counter snapshot.
On SMP kernels, entry->counters.pcnt contains the percpu allocation
address used by x_tables rule counters. A caller can provide a userspace
buffer that faults during the initial fixed-header copy after pcnt has
been copied but before the later sanitized counter copy runs. The syscall
then returns -EFAULT while leaving the raw percpu pointer in userspace.
Copy only the fixed entry prefix before counters from the kernelized rule
blob, then copy the sanitized counter snapshot into the counter field.
Apply this ordering to the IPv4, IPv6, and ARP native and compat
get-entries implementations so a fault cannot expose the internal percpu
counter pointer.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: revalidate bridge ports
ebt_redirect_tg() dereferences br_port_get_rcu() return without a
NULL check, causing a kernel panic when the bridge port has been
removed between the original hook invocation and an NFQUEUE
reinject.
A mere NULL check isn't sufficient, however. As sashiko review
points out userspace can not only remove the port from the bridge,
it could also place the device in a different virtual device, e.g.
macvlan.
If this happens, we must drop the packet, there is no way for us to
reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure.
Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER
too aggressive, which prevents certain logging features when queueing
in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old
CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
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.