In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Don't setup bogus iov_iter for silencing
At transition to the iov_iter for PCM data transfer, we blindly
applied the iov_iter setup also for silencing (i.e. data = NULL), and
it leads to a calculation of bogus iov_iter. Fortunately this didn't
cause troubles on most of architectures but it goes wrong on RISC-V
now, causing a NULL dereference.
Handle the NULL data case to treat the silencing in interleaved_copy()
for addressing the bug above. noninterleaved_copy() has already the
NULL data handling, so it doesn't need changes.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: asihpi: Fix potential OOB array access at reading cache
find_control() to retrieve a cached info accesses the array with the
given index blindly, which may lead to an OOB array access.
Add a sanity check for avoiding it.
In the Linux kernel, the following vulnerability has been resolved:
ipv6: ioam: refresh hdr pointer before ioam6_event()
Reported by Sashiko:
In ipv6_hop_ioam(), the hdr pointer is initialized to point into the
skb's linear data buffer. Later, the code calls skb_ensure_writable(),
which might reallocate the buffer:
if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))
goto drop;
/* Trace pointer may have changed */
trace = (struct ioam6_trace_hdr *)(skb_network_header(skb)
+ optoff + sizeof(*hdr));
ioam6_fill_trace_data(skb, ns, trace, true);
ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),
GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);
If the skb is cloned or lacks sufficient linear headroom,
skb_ensure_writable() will invoke pskb_expand_head(), which reallocates
the skb's data buffer and frees the old one, invalidating pointers to
it. While the code recalculates the trace pointer immediately after the
call to skb_ensure_writable(), it fails to recalculate the hdr pointer.
This patch fixes the above by recalculating the hdr pointer before
passing hdr->opt_len to ioam6_event(), so that we avoid any UaF.
In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: fix initialization of tags of the huge zero folio with init_on_free
__GFP_ZEROTAGS semantics are currently a bit weird, but effectively this
flag is only ever set alongside __GFP_ZERO and __GFP_SKIP_KASAN.
If we run with init_on_free, we will zero out pages during
__free_pages_prepare(), to skip zeroing on the allocation path.
However, when allocating with __GFP_ZEROTAG set, post_alloc_hook() will
consequently not only skip clearing page content, but also skip clearing
tag memory.
Not clearing tags through __GFP_ZEROTAGS is irrelevant for most pages that
will get mapped to user space through set_pte_at() later: set_pte_at() and
friends will detect that the tags have not been initialized yet
(PG_mte_tagged not set), and initialize them.
However, for the huge zero folio, which will be mapped through a PMD
marked as special, this initialization will not be performed, ending up
exposing whatever tags were still set for the pages.
The docs (Documentation/arch/arm64/memory-tagging-extension.rst) state
that allocation tags are set to 0 when a page is first mapped to user
space. That no longer holds with the huge zero folio when init_on_free is
enabled.
Fix it by decoupling __GFP_ZEROTAGS from __GFP_ZERO, passing to
tag_clear_highpages() whether we want to also clear page content.
Invert the meaning of the tag_clear_highpages() return value to have
clearer semantics.
Reproduced with the huge zero folio by modifying the check_buffer_fill
arm64/mte selftest to use a 2 MiB area, after making sure that pages have
a non-0 tag set when freeing (note that, during boot, we will not actually
initialize tags, but only set KASAN_TAG_KERNEL in the page flags).
$ ./check_buffer_fill
1..20
...
not ok 17 Check initial tags with private mapping, sync error mode and mmap memory
not ok 18 Check initial tags with private mapping, sync error mode and mmap/mprotect memory
...
This code needs more cleanups; we'll tackle that next, like
decoupling __GFP_ZEROTAGS from __GFP_SKIP_KASAN.
[akpm@linux-foundation.org: s/__GPF_ZERO/__GFP_ZERO/, per David]
In the Linux kernel, the following vulnerability has been resolved:
mm/migrate_device: fix spinlock leak in migrate_vma_insert_huge_pmd_page
When check_stable_address_space() fails after the PMD spinlock has
been acquired via pmd_lock(), the code jumps directly to the abort
label, bypassing the spin_unlock() call in unlock_abort. This causes
the PMD spinlock to be permanently held, leading to a deadlock.
Change the goto target from abort to unlock_abort to ensure the
spinlock is always released on this error path.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: drop ISO_END frames received without prior ISO_START
ISO data PDUs carry a packet-boundary flag indicating START, CONT, END
or SINGLE. The ISO_CONT branch of iso_recv() guards against a missing
ISO_START by checking conn->rx_len before touching conn->rx_skb, but
ISO_END does not.
If a peer sends an ISO_END as the first packet on a fresh ISO
connection, conn->rx_skb is still NULL and conn->rx_len is zero, so
skb_put(conn->rx_skb, ...) dereferences NULL and oopses. For BIS,
where receivers sync to a broadcaster without pairing, any broadcaster
on the air can trigger this.
Mirror the ISO_CONT check at the top of ISO_END so a stray end fragment
is logged and dropped instead of crashing the host.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: ecred_reconfigure: send packed pdu, not stack pointer
Commit 1c08108f3014 ("Bluetooth: L2CAP: Avoid -Wflex-array-member-not-at-end
warnings") converted the on-stack request PDU in l2cap_ecred_reconfigure()
from an explicit packed struct to DEFINE_RAW_FLEX(), but did not adjust the
size and source-pointer arguments to l2cap_send_cmd():
- struct {
- struct l2cap_ecred_reconf_req req;
- __le16 scid;
- } pdu;
+ DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1);
...
l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
sizeof(pdu), &pdu);
After the conversion, DEFINE_RAW_FLEX() expands to declare an anonymous
union pdu_u plus a local pointer "pdu" pointing at it. Therefore:
- sizeof(pdu) is now sizeof(struct l2cap_ecred_reconf_req *) = 8 on
64-bit (4 on 32-bit), not the 6 bytes of (mtu, mps, scid[1]).
- &pdu is the address of the local pointer's stack storage, not the
address of the request payload.
l2cap_send_cmd() forwards (data, count) to l2cap_build_cmd(), which calls
skb_put_data(skb, data, count). The L2CAP_ECRED_RECONFIGURE_REQ packet
body therefore contains 8 bytes copied from the kernel stack starting at
&pdu -- the 8 bytes overlap the pdu pointer's value, leaking a kernel
stack address to the paired Bluetooth peer. The intended (mtu, mps, scid)
fields are not transmitted at all, so the peer rejects the request as
malformed and the L2CAP_ECRED_RECONFIGURE feature itself has been broken
for the local-side initiator since the introducing commit landed.
The sibling site l2cap_ecred_conn_req() in the same commit was converted
correctly (sizeof(*pdu) + len, pdu); only this site was missed.
Restore the original semantics: pass the full flex-struct size via
struct_size(pdu, scid, 1) and the pdu pointer (the struct address) as
the source.
Validated on a stock 7.0-based host kernel via the real call path:
setsockopt(SOL_BLUETOOTH, BT_RCVMTU, ...) on a BT_CONNECTED
L2CAP_MODE_EXT_FLOWCTL socket emits an L2CAP_ECRED_RECONFIGURE_REQ
whose body is 8 bytes (the on-stack pdu local's value) rather than
the expected 6. Three captures from fresh socket / fresh hciemu peer
on the same host -- low bytes vary per call, high 0xffff confirms a
kernel virtual address (KASLR-randomised stack slot, not a fixed
string):
RECONF_REQ body (ident=0x02 len=8): 42 fb 54 af 0e ca ff ff
RECONF_REQ body (ident=0x02 len=8): 52 3d 2e af 0e ca ff ff
RECONF_REQ body (ident=0x02 len=8): b2 fc 5b af 0e ca ff ff
After this patch the body is 6 bytes carrying the expected
little-endian (mtu, mps, scid).
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MGMT: validate Add Extended Advertising Data length
MGMT_OP_ADD_EXT_ADV_DATA is registered as a variable-length command,
with MGMT_ADD_EXT_ADV_DATA_SIZE as the fixed header size. The handler
then uses cp->adv_data_len and cp->scan_rsp_len to validate and copy
cp->data, but it never checks that those bytes are part of the mgmt
command payload.
A short command can therefore make add_ext_adv_data() pass an
out-of-bounds pointer into tlv_data_is_valid(). If the bytes beyond
the command buffer are addressable, they can also be copied into the
advertising instance as scan response data, where the caller can read
them back via MGMT_OP_GET_ADV_INSTANCE. The trigger requires
CAP_NET_ADMIN in the initial user namespace; KASAN reports an 8-byte
slab-out-of-bounds read.
Reject commands whose length does not match the fixed header plus both
advertising data lengths before parsing cp->data.
In the Linux kernel, the following vulnerability has been resolved:
net: bcmgenet: keep RBUF EEE/PM disabled
Setting RBUF_EEE_EN | RBUF_PM_EN in RBUF_ENERGY_CTRL breaks the RX
path on GENET hardware once MAC EEE becomes active. RX traffic stops
flowing while the link stays up and the usual descriptor/RX error
counters remain quiet. In that state the MAC still accepts frames
(rbuf_ovflow_cnt keeps climbing) but RBUF no longer forwards them to
DMA, so rx_packets is no longer incremented at the netdev level. On
some boards the corruption ends up as a paging fault in
skb_release_data via bcmgenet_rx_poll on an LPI exit.
Reproduced on Pi 4B (BCM2711 + BCM54213PE) and confirmed by Florian
Fainelli on an internal Broadcom 4908-family board with the same crash
signature. RBUF_PM_EN is not publicly documented.
This shows up more often now that phy_support_eee() enables EEE by
default, but it also affects older kernels as soon as TX LPI is
turned on via ethtool, so it is not specific to recent changes.
Always clear RBUF_EEE_EN | RBUF_PM_EN in bcmgenet_eee_enable_set so
the bits stay off across resets. UMAC and TBUF setup is left alone so
TX-side EEE keeps working.
In the Linux kernel, the following vulnerability has been resolved:
net: devmem: reject dma-buf bind with non-page-aligned size or SG length
net_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be
PAGE_SIZE multiples without checking:
- tx_vec is sized dmabuf->size / PAGE_SIZE, and
net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size
before indexing tx_vec[virt_addr / PAGE_SIZE]. With size =
N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base =
N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past.
- owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner()
covers the full byte len, so a non-page-multiple non-final sg
desyncs num_niovs from the gen_pool region for every later sg, on
both RX and TX.
dma-buf does not require page-aligned sizes, so the bind path has to
enforce what its own indexing assumes. Reject both with -EINVAL.
The size check is TX-only (only tx_vec is sized off dmabuf->size); the
SG-length check covers both directions.
In the Linux kernel, the following vulnerability has been resolved:
net: hsr: defer node table free until after RCU readers
HSR node-list and node-status generic-netlink operations run under
rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and
hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table
with plain list_del() and frees each node immediately.
That lets a generic-netlink reader hold a struct hsr_node pointer across
hsr_dellink(). In a KASAN build, widening the reader window after
hsr_get_next_node() obtains the node reproduces a slab-use-after-free
when the reader copies node->macaddress_A; the freeing stack is
hsr_del_nodes() from hsr_dellink().
Use list_del_rcu() and defer the free through the existing
hsr_free_node_rcu() callback. This matches the lifetime rule used by the
HSR prune paths, which already delete nodes with list_del_rcu() and
call_rcu().
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix use-after-free in mlx5e_tx_reporter_timeout_recover
mlx5e_tx_reporter_timeout_recover() accesses sq->netdev after
mlx5e_safe_reopen_channels() has torn down and freed the channel (and
its embedded SQs). Replace the three sq->netdev references with
priv->netdev which is safe because priv outlives channel teardown.
The netdev_err() call already used priv->netdev for this reason; make
the trylock/unlock and health_channel_eq_recover calls consistent.
This fixes the following KASAN splat:
BUG: KASAN: use-after-free in mlx5e_tx_reporter_timeout_recover+0x1dd/0x360 [mlx5_core]
Read of size 8 at addr ffff889860ed0b28 by task kworker/u113:2/5277
Call Trace:
mlx5e_tx_reporter_timeout_recover+0x1dd/0x360 [mlx5_core]
devlink_health_reporter_recover+0xa2/0x150
devlink_health_report+0x254/0x7c0
mlx5e_reporter_tx_timeout+0x297/0x380 [mlx5_core]
mlx5e_tx_timeout_work+0x109/0x170 [mlx5_core]
process_one_work+0x677/0xf20
worker_thread+0x51f/0xd90
kthread+0x3a5/0x810
ret_from_fork+0x208/0x400
ret_from_fork_asm+0x1a/0x30
In the Linux kernel, the following vulnerability has been resolved:
net: ifb: report ethtool stats over num_tx_queues
ifb_dev_init() allocates dp->tx_private to dev->num_tx_queues
entries via kzalloc_objs(*txp, dev->num_tx_queues). Both IFB
per-queue RX and TX stats live in those entries: ifb_xmit() updates
txp->rx_stats using the skb queue mapping, ifb_ri_tasklet() updates
txp->tx_stats, and ifb_stats64() aggregates both over
dev->num_tx_queues.
The ethtool stats callbacks instead size and walk the per-queue
stats with dev->real_num_rx_queues and dev->real_num_tx_queues. With
an asymmetric device where the RX queue count exceeds the TX queue
count, for example:
ip link add name ifb10 numtxqueues 1 numrxqueues 8 type ifb
ethtool -S ifb10
ifb_get_ethtool_stats() indexes past the tx_private allocation and
copies adjacent slab data through ETHTOOL_GSTATS.
Use dev->num_tx_queues consistently for the stats strings, the
stats count, and the stats data walks. This reports one RX stats
group and one TX stats group for each backing ifb_q_private entry,
which is the queue set IFB can actually populate.
Reproduced under UML+KASAN at v7.1-rc2:
BUG: KASAN: slab-out-of-bounds in ifb_fill_stats_data+0x3c/0xae
Read of size 8 at addr 0000000062dbd228 by task ethtool/36
ifb_fill_stats_data+0x3c/0xae
ifb_get_ethtool_stats+0xc0/0x129
__dev_ethtool+0x1ca5/0x363c
dev_ethtool+0x123/0x1b3
dev_ioctl+0x56c/0x744
sock_do_ioctl+0x15f/0x1b2
sock_ioctl+0x4d5/0x50a
sys_ioctl+0xd8b/0xde9
With the patch applied, the same UML+KASAN repro is silent and
ethtool -S ifb10 reports only the stats backed by the single
allocated tx_private entry.
In the Linux kernel, the following vulnerability has been resolved:
net: ethtool: fix NULL pointer dereference in phy_reply_size
In phy_prepare_data(), several strings such as 'name', 'drvname',
'upstream_sfp_name', and 'downstream_sfp_name' are allocated using
kstrdup(). However, these allocations were not checked for failure.
If kstrdup() fails for 'name', it returns NULL while the function
continues. This leads to a kernel NULL pointer dereference and panic
later in phy_reply_size() when it unconditionally calls strlen() on
the NULL pointer.
While other strings like 'upstream_sfp_name' might be checked before
access in certain code paths, failing to handle these allocations
consistently can lead to incomplete data reporting or hidden bugs.
Fix this by adding proper NULL checks for all kstrdup() calls in
phy_prepare_data() and implement a centralized error handling path
using goto labels to ensure all previously allocated resources are
freed on failure.
In the Linux kernel, the following vulnerability has been resolved:
l2tp: use list_del_rcu in l2tp_session_unhash
An unprivileged local user can pin a host CPU indefinitely in
l2tp_session_get_by_ifname() by issuing L2TP_CMD_SESSION_GET on
L2TP_ATTR_IFNAME concurrently with L2TP_CMD_SESSION_CREATE and
L2TP_CMD_SESSION_DELETE on the same tunnel. All three commands take
GENL_UNS_ADMIN_PERM, so CAP_NET_ADMIN in the netns user namespace
suffices; on any host that has l2tp_core loaded the trigger is
reachable from a standard `unshare -Urn` sandbox.
l2tp_session_unhash() removes a session from tunnel->session_list
with list_del_init(), but that list is walked by
l2tp_session_get_by_ifname() with list_for_each_entry_rcu() under
rcu_read_lock_bh(). list_del_init() leaves the deleted entry's
next/prev self-pointing; a reader that has loaded the entry and
then advances pos->list.next reads &session->list, container_of()s
back to the same session, and list_for_each_entry_rcu() never
reaches the list head. The CPU stays in strcmp() inside the
walker, with BH and preemption disabled, so RCU grace periods on
the host stall behind it and the wedged thread cannot be killed
(SIGKILL is delivered on syscall return).
Use list_del_rcu() to match the existing list_add_rcu() in
l2tp_session_register(); the deleted session remains visible to
in-flight walkers with consistent next/prev pointers until
kfree_rcu() in l2tp_session_free() releases it. tunnel->session_list
has exactly one list_del_init() call site; the list_del_init
(&session->clist) at l2tp_core.c:533 operates on the per-collision
list, which is not walked under RCU. list_empty(&session->list) is
not used anywhere in net/l2tp/ after the unhash point, so dropping
the post-delete self-init is safe; the fix has no userspace-visible
behavior change.
In the Linux kernel, the following vulnerability has been resolved:
qed: fix double free in qed_cxt_tables_alloc()
If one of the later PF or VF CID bitmap allocations fails,
qed_cid_map_alloc() jumps to cid_map_fail and frees the previously
allocated CID bitmaps before returning an error. qed_cxt_tables_alloc()
then calls qed_cxt_mngr_free(), which invokes qed_cid_map_free()
again.
Fix this by setting each CID bitmap pointer to NULL after bitmap_free()
to avoid double free.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1-rc3.
Runtime reproduction was not attempted because exercising the failing
allocation path requires device-specific setup.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb
ieee80211_invoke_fast_rx() reads RX status through
IEEE80211_SKB_RXCB(skb), which aliases the same skb->cb storage
that ieee80211_rx_mesh_data() reuses as IEEE80211_TX_INFO. In the
unicast forward path, mesh_data does:
info = IEEE80211_SKB_CB(fwd_skb);
memset(info, 0, sizeof(*info));
on the same skb the caller still names via rx->skb, then either
queues the skb for TX (success) or kfree_skb()'s it (no-route)
before returning RX_QUEUED. The caller's RX_QUEUED arm then
calls sta_stats_encode_rate(status) on memory that is either
zeroed (success path) or freed (no-route path). The latter is
KASAN slab-use-after-free in ieee80211_prepare_and_rx_handle.
Fix by encoding the rate from status before invoking
ieee80211_rx_mesh_data(), so the RX_QUEUED arm consumes a value
captured while status was still backed by valid memory.
In the Linux kernel, the following vulnerability has been resolved:
ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()
Reported by Sashiko:
The function ipv6_hop_ioam() accesses
__in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned
idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr
via RCU, __in6_dev_get() can return NULL during interface teardown, which
could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop
option.
Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly.
In the Linux kernel, the following vulnerability has been resolved:
vsock/vmci: fix UAF when peer resets connection during handshake
vmci_transport_recv_connecting_server() returned err = 0 for a peer
RST in its default switch arm:
err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
That made vmci_transport_recv_listen() skip vsock_remove_pending(),
leaving the pending socket on the listener's pending_links with
sk_state = TCP_CLOSE while destroy: still dropped the explicit
reference taken before schedule_delayed_work().
One second later vsock_pending_work() observed is_pending=true and
performed full cleanup: vsock_remove_pending() then the two trailing
sock_put(sk) calls -- the first reached refcount 0 and __sk_freed
the socket, and the second wrote into the freed object:
BUG: KASAN: slab-use-after-free in refcount_warn_saturate
Write of size 4 at addr ffff88800b1cac80 by task kworker
Workqueue: events vsock_pending_work
Treat peer RST like any other unexpected packet type (err = -EINVAL).
All destroy: arms now return err < 0, so vmci_transport_recv_listen()
removes pending from pending_links synchronously and
vsock_pending_work() takes the is_pending=false / !rejected branch,
dropping only its own work reference. This also closes the
multi-packet race Sashiko reported on v2: pending is removed from
the list before any subsequent packet can find it.
The pre-existing sk_acceptq_removed() gap on the err < 0 path of
vmci_transport_recv_listen() that Sashiko also noted is not
introduced or changed by this patch.
Tested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched.
In the Linux kernel, the following vulnerability has been resolved:
ipv4: raw: reject IP_HDRINCL packets with ihl < 5
raw_send_hdrinc() validates that the caller-supplied IPv4 header
fits within the message length:
iphlen = iph->ihl * 4;
err = -EINVAL;
if (iphlen > length)
goto error_free;
if (iphlen >= sizeof(*iph)) {
/* fix up saddr, tot_len, id, csum, transport_header */
}
It does not, however, reject ihl < 5. For such a packet the
"if (iphlen >= sizeof(*iph))" branch is skipped, leaving the
crafted iphdr untouched, but the packet is still handed to
__ip_local_out() and onward. Downstream consumers that read
iph->ihl assume a sane value: net/ipv4/ah4.c:ah_output() in
particular subtracts sizeof(struct iphdr) from top_iph->ihl * 4
and passes the (signed-int-negative, then cast to size_t)
result to memcpy(), producing an OOB access of length close to
SIZE_MAX and a host kernel panic.
An IPv4 header with ihl < 5 is malformed by definition (RFC 791:
"Internet Header Length is the length of the internet header in
32 bit words ... Note that the minimum value for a correct header
is 5."). The kernel should not be willing to inject such a
packet into its own output path.
Reject "iphlen < sizeof(*iph)" alongside the existing
"iphlen > length" check. This matches the principle that locally
constructed packets that re-enter the IP stack must pass the same
basic sanity tests that a foreign packet would be subjected to.
Once this lands, the "if (iphlen >= sizeof(*iph))" wrapper around
the fixup branch becomes redundant; left in place to keep the
patch minimal and backport-friendly. A follow-up can unwrap it.
Note that commit 86f4c90a1c5c ("ipv4, ipv6: ensure raw socket
message is big enough to hold an IP header") ensures the message
buffer is large enough to hold an iphdr, but does not constrain
the self-reported iph->ihl.
Reachability: the malformed packet source is any caller with
CAP_NET_RAW, including an unprivileged process in a user+net
namespace on a kernel with CONFIG_USER_NS=y. The reproduced AH
crash also requires a matching xfrm AH policy on the outgoing
route; a container granted CAP_NET_ADMIN can install that state
and policy in its netns. Loopback bypasses xfrm_output, so the
trigger uses a real netdev.
Reproduced on UML + KASAN: kernel-mode fault at addr 0x0 with
memcpy_orig at the crash site. Same shape reproduces inside a
rootless Docker container with --cap-add NET_ADMIN on a stock
distro kernel.
In the Linux kernel, the following vulnerability has been resolved:
ixgbevf: fix use-after-free in VEPA multicast source pruning
ixgbevf_clean_rx_irq() prunes frames whose source MAC matches the VF's
own address (VEPA multicast workaround) by freeing the skb and
continuing to the next descriptor:
dev_kfree_skb_irq(skb);
continue;
The skb pointer is declared outside the while loop and persists across
iterations. Because the continue skips the "skb = NULL" reset at the
bottom of the loop, the next iteration enters the "else if (skb)" path
and calls ixgbevf_add_rx_frag() on the freed skb, dereferencing
skb_shinfo(skb)->nr_frags - a use-after-free in NAPI softirq context.
The sibling driver iavf already handles this correctly by nulling the
pointer before continuing. Apply the same pattern here.
I do not have ixgbevf hardware; the bug was found by static analysis
(scan_drop_continue_loops.py + semgrep drop_continue_in_loop, multi-tool
corroboration with the highest score in the scan). The UAF was confirmed
under KASAN by loading a test module that reproduces the exact code
pattern (alloc skb, kfree_skb, then read skb_shinfo(skb)->nr_frags):
BUG: KASAN: slab-use-after-free in ixgbevf_uaf_test_init+0x100/0x1000
Read of size 8 at addr 000000006163ae78 by task insmod/30
freed 208-byte region [000000006163adc0, 000000006163ae90)
QEMU emulates igb (82576) but not ixgbe (82599), and the igbvf VF
driver does not include the VEPA source pruning path, so a full
end-to-end reproduction with emulated hardware was not possible.
In the Linux kernel, the following vulnerability has been resolved:
rbd: eliminate a race in lock_dwork draining on unmap
Given how rbd_lock_add_request() and rbd_img_exclusive_lock() are
written, lock_dwork may be (re)queued more than it's actually needed:
for example in case a new I/O request comes in while we are in the
middle of rbd_acquire_lock() on behalf of another I/O request. This is
expected and with rbd_release_lock() preemptively canceling lock_dwork
is benign under normal operation.
A more problematic example is maybe_kick_acquire():
if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
}
It's not unrealistic for lock_dwork to get canceled right after
delayed_work_pending() returns true and for mod_delayed_work() to
requeue it right there anyway. This is a classic TOCTOU race.
When it comes to unmapping the image, there is an implicit assumption
of no self-initiated exclusive lock activity past the point of return
from rbd_dev_image_unlock() which unlocks the lock if it happens to be
held. This unlock is assumed to be final and lock_dwork (as well as
all other exclusive lock tasks, really) isn't expected to get queued
again. However, lock_dwork is canceled only in cancel_tasks_sync()
(i.e. later in the unmap sequence) and on top of that the cancellation
can get in effect nullified by maybe_kick_acquire(). This may result
in rbd_acquire_lock() executing after rbd_dev_device_release() and
rbd_dev_image_release() run and free and/or reset a bunch of things.
One of the possible failure modes then is a violated
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
in rbd_dev_header_info() which is called via rbd_dev_refresh() from
rbd_post_acquire_action().
Redo exclusive lock task draining to provide saner semantics and try
to meet the assumptions around rbd_dev_image_unlock().
In the Linux kernel, the following vulnerability has been resolved:
lsm: hold cred_guard_mutex for lsm_set_self_attr()
Just as proc_pid_attr_write() already does before calling the LSM
hook. This only matters for SELinux and AppArmor which check
whether the process is being ptraced and if so, whether to
allow the transition.
In the Linux kernel, the following vulnerability has been resolved:
igc: fix potential skb leak in igc_fpe_xmit_smd_frame()
When igc_fpe_init_tx_descriptor() fails, no one takes care of an
allocated skb, leaking it. [1]
Use dev_kfree_skb_any() on failure.
Tested on an I226 adapter with the following command, while injecting
faults in igc_fpe_init_tx_descriptor() to trigger the error path.
# ethtool --set-mm $DEV verify-enabled on tx-enabled on pmac-enabled on
[1]
unreferenced object 0xffff888113c6cdc0 (size 224):
...
backtrace (crc be3d3fda):
kmem_cache_alloc_node_noprof+0x3b1/0x410
__alloc_skb+0xde/0x830
igc_fpe_xmit_smd_frame.isra.0+0xad/0x1b0
igc_fpe_send_mpacket+0x37/0x90
ethtool_mmsv_verify_timer+0x15e/0x300
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Fix UAF read of tail->len in unix_stream_data_wait()
unix_stream_data_wait() does skb_peek_tail(&sk->sk_receive_queue) without
holding any lock that prevents SKBs on that queue from being dequeued and
freed.
This has been the case since commit 79f632c71bea ("unix/stream: fix
peeking with an offset larger than data in queue").
The first consequence of this is that the pointer comparison
`tail != last` can be false even if `last` semantically refers to an
already-freed SKB while `tail` is a new SKB allocated at the same address;
which can cause unix_stream_data_wait() to wrongly keep blocking after new
data has arrived, but only in a weird scenario where a peeking recv() and
a normal recv() on the same socket are racing, which is probably not a
real problem.
But since commit 2b514574f7e8 ("net: af_unix: implement splice for stream
af_unix sockets"), `tail` is actually dereferenced, which can cause UAF in
the following race scenario (where test_setup() runs single-threaded,
and afterwards, test_thread1() and test_thread2() run concurrently in
two threads:
```
static int socks[2];
void test_setup(void) {
socketpair(AF_UNIX, SOCK_STREAM, 0, socks);
send(socks[1], "A", 1, 0);
int peekoff = 1;
setsockopt(socks[0], SOL_SOCKET, SO_PEEK_OFF, &peekoff, sizeof(peekoff));
}
void test_thread1(void) {
char dummy;
recv(socks[0], &dummy, 1, MSG_PEEK);
}
void test_thread2(void) {
char dummy;
recv(socks[0], &dummy, 1, 0);
shutdown(socks[1], SHUT_WR);
}
```
when racing like this:
```
thread1 thread2
unix_stream_read_generic
mutex_lock(&u->iolock)
skb_peek(&sk->sk_receive_queue)
skb_peek_next(skb, &sk->sk_receive_queue)
mutex_unlock(&u->iolock)
unix_stream_read_generic
unix_state_lock(sk)
skb_peek(&sk->sk_receive_queue)
unix_state_unlock(sk)
unix_stream_data_wait
unix_state_lock(sk)
tail = skb_peek_tail(&sk->sk_receive_queue)
spin_lock(&sk->sk_receive_queue.lock)
__skb_unlink(skb, &sk->sk_receive_queue)
spin_unlock(&sk->sk_receive_queue.lock)
consume_skb(skb) [frees the SKB]
`tail != last`: false
`tail`: true
`tail->len != last_len` ***UAF***
```
Fix the UAF by removing the read of tail->len; checking tail->len would
only make sense if SKBs in the receive queue of a UNIX socket could grow,
which can no longer happen.
Kuniyuki explained:
> When commit 869e7c62486e ("net: af_unix: implement stream sendpage
> support") added sendpage() support, data could be appended to the last
> skb in the receiver's queue.
>
> That's why we needed to check if the length of the last skb was changed
> while waiting for new data in unix_stream_data_wait().
>
> However, commit a0dbf5f818f9 ("af_unix: Support MSG_SPLICE_PAGES") and
> commit 57d44a354a43 ("unix: Convert unix_stream_sendpage() to use
> MSG_SPLICE_PAGES") refactored sendmsg(), and now data is always added
> to a new skb.
That means this fix is not suitable for kernels before 6.5.
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix busy dentry used after unmounting
Since commit 340cea84f691c ("cifs: open files should not hold ref on
superblock"), cifs file only holds the dentry ref_cnt, the cifs file
close work(cfile->deferred) could be executed after unmounting, which
will trigger a warning in generic_shutdown_super:
BUG: Dentry 00000000a14a6845{i=c,n=file} still in use (1) [unmount of
cifs cifs]
The detailed processs is:
process A process B kworker
fd = open(PATH)
vfs_open
file->__f_path = *path // dentry->d_lockref.count = 1
cifs_open
cifs_new_fileinfo
cfile->dentry = dget(dentry) // dentry->d_lockref.count = 2
close(fd)
__fput
cifs_close
queue_delayed_work(deferredclose_wq, cfile->deferred)
dput(dentry) // dentry->d_lockref.count = 1
smb2_deferred_work_close
_cifsFileInfo_put
list_del(&cifs_file->flist)
umount
cleanup_mnt
deactivate_super
cifs_kill_sb
cifs_close_all_deferred_files_sb
cifs_close_all_deferred_files
// cannot find cfile, skip _cifsFileInfo_put
kill_anon_super
generic_shutdown_super
shrink_dcache_for_umount
umount_check
WARN ! // dentry->d_lockref.count = 1
cifsFileInfo_put_final
dput(cifs_file->dentry)
// dentry->d_lockref.count = 0
Fix it by flushing 'deferredclose_wq' before calling kill_anon_super.
Fetch a reproducer in https://bugzilla.kernel.org/show_bug.cgi?id=221548.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: pcm512x: fix null-ptr dereference in pcm512x_overclock_xxx_put()
In the pcm512x chipset driver, pcm512x_overclock_xxx_put() is defined as
a general mixer kcontrol instead of a DAPM kcontrol, so struct
snd_soc_dapm_context must not be accessed via
snd_soc_dapm_kcontrol_to_dapm().
This causes a NULL pointer dereference, so it must be modified to use
snd_soc_component_to_dapm().
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits
Userspace can restore an ITS Device Table Entry whose Size field encodes
more EventID bits than the virtual ITS supports. The live MAPD path
rejects that state, but vgic_its_restore_dte() accepts it and stores the
out-of-range value in dev->num_eventid_bits.
Reject restored DTEs with num_eventid_bits > VITS_TYPER_IDBITS before
allocating the device. This mirrors the MAPD check and prevents the
restored state from reaching vgic_its_restore_itt(), where the unchecked
value can be converted into an oversized scan_its_table() range.
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic: Free private_irqs when init fails after allocation
Companion to commit 250f25367b58 ("KVM: arm64: Tear down vGIC on
failed vCPU creation"), which added the missing kvm_vgic_vcpu_destroy()
call to the kvm_share_hyp() failure path in kvm_arch_vcpu_create(). The
kvm_vgic_vcpu_init() failure path immediately above it has the same
shape and still needs the same cleanup.
Call kvm_vgic_vcpu_destroy() when kvm_vgic_vcpu_init() fails so private
IRQs allocated before a redistributor iodev registration failure are
released before the failed vCPU is freed.
In the Linux kernel, the following vulnerability has been resolved:
virt: sev-guest: Explicitly leak pages in unknown state
When set_memory_{encrypted,decrypted}() fail, the user cannot know at which
point the function failed, meaning that the pages are left in an unknown state
from the point of view of the caller.
Since the pages may be left in an unencrypted state, they are not suitable for
general use, and cannot be returned safely to the buddy allocator. Avoid the
issue by never freeing the pages, and then do the proper accounting by calling
snp_leak_pages().
In the Linux kernel, the following vulnerability has been resolved:
scsi: isci: Fix use-after-free in device removal path
The ISCI completion tasklet is initialized in isci_host_alloc()
(drivers/scsi/isci/init.c:496) and scheduled from both MSI-X and legacy
interrupt handlers (drivers/scsi/isci/host.c:223,613).
isci_host_deinit() stops the controller and waits for stop completion,
but it never kills completion_tasklet before teardown continues. A
top-of-function tasklet_kill() is not sufficient here: interrupts are
only disabled when isci_host_stop_complete() runs, so until
wait_for_stop() returns the IRQ handlers can still requeue the
tasklet. The tasklet callback also re-enables interrupts after draining
completions, so killing the tasklet before the source is quiesced leaves
the same race open.
Once wait_for_stop() returns, no further IRQ-driven scheduling can
occur. Kill completion_tasklet there so teardown cannot race a queued
tasklet running on a dead ihost. On remove or unload, the stale callback
can otherwise dereference ihost and touch ihost->smu_registers after the
host lifetime ends.
A UML + KASAN analogue reproduced the failure class both with no
tasklet_kill() and with tasklet_kill() placed before source quiesce, and
stayed clean once the kill happened after quiescing the scheduling
source.
This mirrors commit f6ab594672d4 ("scsi: aic94xx: fix use-after-free in
device removal path"), but ISCI needs the kill after wait_for_stop().
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Reject MPA FPDU length underflow before signed receive math
A malicious connected siw peer can send an iWARP FPDU whose MPA length
field (c_hdr->mpa_len, 16 bit big-endian, peer-controlled) is smaller
than the fixed DDP/RDMAP header for the announced opcode. Soft-iWARP
parses the full header in siw_get_hdr() based on iwarp_pktinfo[opcode]
.hdr_len, but never compares mpa_len against that header length.
siw_tcp_rx_data() then derives
srx->fpdu_part_rem = be16_to_cpu(mpa_len) - fpdu_part_rcvd
+ MPA_HDR_SIZE;
where fpdu_part_rcvd equals iwarp_pktinfo[opcode].hdr_len at this
point. For a tagged WRITE (hdr_len 16, MPA_HDR_SIZE 2) the smallest
on-wire mpa_len of 0 yields fpdu_part_rem = -14, and any mpa_len below
hdr_len - MPA_HDR_SIZE underflows to a negative int.
The signed value then flows into siw_proc_write()/siw_proc_rresp() as
bytes = min(srx->fpdu_part_rem, srx->skb_new);
is handed to siw_check_mem() as an int len (whose interval check
addr + len > mem->va + mem->len is satisfied for a valid base when
len is negative), and reaches siw_rx_data() -> siw_rx_kva() /
siw_rx_umem() -> skb_copy_bits() as a signed copy length. The header
copy branch in skb_copy_bits() promotes that to size_t, producing a
multi-gigabyte read.
KASAN under a KUnit harness that drives the real kernel TCP receive
path -- a loopback AF_INET socketpair, the malformed FPDU written via
kernel_sendmsg, sk_data_ready firing in softirq, tcp_read_sock
dispatching to siw_tcp_rx_data -- reports:
BUG: KASAN: use-after-free in skb_copy_bits+0x284/0x480
Read of size 4294967295 at addr ffff888...
Call Trace:
skb_copy_bits
siw_rx_kva
siw_rx_data
siw_check_mem
siw_proc_write
siw_tcp_rx_data
__tcp_read_sock
siw_qp_llp_data_ready
tcp_data_ready
tcp_data_queue
Add the missing invariant at the earliest point where the peer header
is fully assembled. iwarp_pktinfo[*].hdr_len - MPA_HDR_SIZE is exactly
the value the siw transmitter uses as the minimum mpa_len for each
opcode (drivers/infiniband/sw/siw/siw_qp.c:33), so this matches the
protocol contract. Out-of-range FPDUs terminate the connection with
TERM_ERROR_LAYER_LLP / LLP_ETYPE_MPA / LLP_ECODE_FPDU_START -- which
is RFC 5044 Section 8 error code 3 ("Marker and ULPDU Length fields
do not agree on the start of an FPDU"), the correct framing-error
class for this inconsistency.
In the Linux kernel, the following vulnerability has been resolved:
fwctl: pds: Validate RPC input size before parsing
The fwctl core allocates the device-specific RPC input buffer with
fwctl_rpc.in_len and passes that buffer to the driver callback.
pdsfc_fw_rpc() casts the buffer to struct fwctl_rpc_pds and then calls
pdsfc_validate_rpc(), which reads fields from that structure before
checking that the input buffer is large enough to contain it. A short
in_len can make pds_fwctl read beyond the allocation.
Reject pds RPC buffers that are smaller than struct fwctl_rpc_pds before
parsing any pds-specific fields.
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Fix use-after-free of CPU job query arrays on error path
The CPU job ioctl's fail label calls kvfree() on cpu_job's timestamp and
performance query arrays after v3d_job_cleanup(), which drops the job's
last reference and frees cpu_job. Reading cpu_job at that point is a
use-after-free. Also, on the early v3d_job_init() failure path, it is a
NULL dereference, since v3d_job_deallocate() zeroes the local pointer.
In the success path, the arrays are released from the scheduler's
.free_job callback, but on the error path, they are freed manually, as
the job was never pushed to the scheduler. While the success path deals
with this correctly, the fail path doesn't.
On top of that, the manual kvfree() calls only free the array storage;
they don't drm_syncobj_put() the per-query syncobjs that
v3d_timestamp_query_info_free() and v3d_performance_query_info_free()
release on the success path. So the same fail path that triggers the
use-after-free also leaks one syncobj reference per query.
Unify the CPU job teardown into the CPU job's kref destructor, mirroring
v3d_render_job_free(). The scheduler's .free_job slot reverts to the
generic v3d_sched_job_free() and the fail label drops the manual
kvfree() calls, leaving a single teardown path that is reached from both
the scheduler and the ioctl error path. That removes the use-after-free,
the NULL dereference, and the syncobj leak by construction.
In the Linux kernel, the following vulnerability has been resolved:
drm/virtio: use uninterruptible resv lock for plane updates
virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush() lock
the framebuffer BO's dma_resv via virtio_gpu_array_lock_resv() and
ignore its return value. The function can fail with -EINTR from
dma_resv_lock_interruptible() (signal during lock wait) or with
-ENOMEM from dma_resv_reserve_fences() (fence slot allocation),
leaving the resv lock not held. The queue path then walks the object
array and calls dma_resv_add_fence(), which requires the lock held;
with lockdep enabled this trips dma_resv_assert_held():
WARNING: drivers/dma-buf/dma-resv.c:296 at dma_resv_add_fence+0x71e/0x840
Call Trace:
virtio_gpu_array_add_fence
virtio_gpu_queue_ctrl_sgs
virtio_gpu_queue_fenced_ctrl_buffer
virtio_gpu_cursor_plane_update
drm_atomic_helper_commit_planes
drm_atomic_helper_commit_tail
commit_tail
drm_atomic_helper_commit
drm_atomic_commit
drm_atomic_helper_update_plane
__setplane_atomic
drm_mode_cursor_universal
drm_mode_cursor_common
drm_mode_cursor_ioctl
drm_ioctl
__x64_sys_ioctl
Beyond the WARN, mutating the dma_resv fence list without the lock
races with concurrent readers/writers and can corrupt the list.
Both call sites run inside the .atomic_update plane callback, which
DRM atomic helpers do not allow to fail (by the time it runs, the
commit has been signed off to userspace and there is no clean
rollback path). Moving the lock acquisition to .prepare_fb was
rejected because the broader lock scope deadlocks against other BO
locking paths in the same atomic commit.
Introduce virtio_gpu_lock_one_resv_uninterruptible() that uses
dma_resv_lock() instead of dma_resv_lock_interruptible(). This
eliminates the -EINTR failure mode -- the realistic syzbot trigger
-- without extending the lock hold across the commit. The helper
locks a single BO and rejects nents > 1 with -EINVAL; both fix
sites lock exactly one BO.
Use it from virtio_gpu_cursor_plane_update() and
virtio_gpu_resource_flush(); check the return value to handle the
remaining -ENOMEM case from dma_resv_reserve_fences() by freeing
the objs and skipping the plane update for that frame. The
framebuffer BOs touched here are not shared with other contexts
and lock contention is expected to be brief, so the loss of
signal-interruptibility is acceptable.
Other callers of virtio_gpu_array_lock_resv() (the ioctl paths)
continue to use the interruptible variant.
The bug was reported by syzbot, triggered via fault injection
(fail_nth) on the DRM_IOCTL_MODE_CURSOR path, which forces the
-ENOMEM branch in dma_resv_reserve_fences().
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Validate GPIO pin LUT table size before iterating
[Why&How]
The GPIO pin table parsers in get_gpio_i2c_info() and
bios_parser_get_gpio_pin_info() derive an element count from the VBIOS
table_header.structuresize field, then iterate over gpio_pin[] entries.
However, GET_IMAGE() only validates that the table header itself fits
within the BIOS image. If the VBIOS reports a structuresize larger than
the actual mapped data, the loop reads past the end of the BIOS image,
causing an out-of-bounds read.
Fix this by calling bios_get_image() to validate that the full claimed
structuresize is accessible within the BIOS image before entering the
loop in both functions.
(cherry picked from commit ba5e95b43b773ae1bf1f66ee6b31eb774e65afe3)
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: mcast: fix use-after-free in orig_node RCU release
batadv_mcast_purge_orig() removes entries from RCU-protected hlists but
does not wait for an RCU grace period before returning. Concurrent RCU
readers may still accesses references to those entries at the point of
removal. RCU-protected readers trying to operate on entries like
orig->mcast_want_all_ipv6_node will then access already freed memory.
Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(),
just before the call_rcu() invocation. This ensures RCU readers that were
active at purge time have drained before the orig_node memory is reclaimed.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: avoid double decrement of bla.num_requests
The bla.num_requests is increased when no request_sent was in progress. And
it is decremented in various places (announcement was received, backbone is
purged, periodic work). But the check if the request_sent is actually set
to a specific state and the atomic_dec/_inc are not safe because they are
not atomic (TOCTOU) and multiple such code portions can run concurrently.
At the same time, it is necessary to modify request_sent (state) and
bla.num_requests atomically. Otherwise batadv_bla_send_request() might set
request_sent to 1 and is interrupted. batadv_handle_announce() can then
set request_sent back to 0 and decrement num_requests before
batadv_bla_send_request() incremented it.
The two operations must therefore be locked. And since state (request_sent)
and wait_periods are only accessed inside this lock, they can be converted
to simpler datatypes. And to avoid that the bla.num_requests is touched by
a parallel running context with a valid backbone_gw reference after
batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to
correctly signal that a backbone_gw is in the state of being cleaned up.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: avoid NULL-ptr deref for claim via dropped interface
Without rtnl_lock held, a hardif might be retrieved as primary interface of
a meshif, but then (while operating on this interface) getting decoupled
from the mesh interface. In this case, the meshif still exists but the
pointer from the primary hardif to the meshif is set to NULL.
The mesh_iface must be checked first to be non-NULL before continuing to
send an ARP request using meshif.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tp_meter: directly shut down timer on cleanup
batadv_tp_sender_cleanup() was calling timer_delete_sync() followed by
timer_delete() to guard against the timer handler re-arming itself between
the two calls. This double-deletion hack relied on the sending status being
set to 0 to suppress re-arming.
Replace both calls with a single timer_shutdown_sync(). This function both
waits for any running timer callback to complete (like timer_delete_sync())
and permanently disarms the timer so it cannot be re-armed afterwards,
making re-arming prevention unconditional and self-documenting.
The re-arming property is also required because otherwise:
1. context 0 (batadv_tp_recv_ack()) checks in
batadv_tp_reset_sender_timer() if sending is still 1 -> it is
2. context 1 changes in batadv_tp_sender_shutdown() sending to 0 and in
this process forces the kthread to stop timer in
batadv_tp_sender_cleanup()
3. context 0 continues in batadv_tp_reset_sender_timer() and rearms the
timer -> but the reference for it is already gone
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tp_meter: fix tp_vars reference leak in receiver shutdown
The receiver shutdown timer handler, batadv_tp_receiver_shutdown(), is
responsible for releasing the tp_vars reference it holds. However, the
existing logic for coordinating this release with batadv_tp_stop_all() was
flawed.
timer_shutdown_sync() guarantees the timer will not fire again after it
returns, but it returns non-zero only when the timer was pending at the
time of the call. If the timer had already expired (and
batadv_tp_stop_all() would unsucessfully try to rearm itself),
batadv_tp_stop_all() skips its batadv_tp_vars_put(), and
batadv_tp_receiver_shutdown() fails to put its own reference as well.
Fix this by introducing a new atomic variable receiving that is set to 1
when the receiver is initialized and cleared atomically with atomic_xchg()
by whichever side claims it first. Only the side that observes the
transition from 1 to 0 is responsible for releasing the tp_vars timer
reference, eliminating the uncertainty.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tt: fix TOCTOU race for reported vlans
The local TT based TVLV is generated by first checking the number of VLANs
which have at least one TT entry. A new buffer with the correct size for
the VLANs is then allocated. Only then, the list of VLANs s used to fill
the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock
is held. But the actual number of TT entries of each VLAN can still
increase during this time - just not the number of VLANs in the list.
But the prefilter used in the buffer size calculation might still cause an
increase of the number of VLANs which need to be stored. Simply because a
VLAN might now suddenly have at least one entry when it had none in the
pre-alloc check - and then needs to occupy space which was not allocated.
It is better to overestimate the buffer size at the beginning and then fill
the buffer only with the VLANs which are not empty.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tt: avoid empty VLAN responses
The commit 16116dac2339 ("batman-adv: prevent TT request storms by not
sending inconsistent TT TLVLs") added checks to the local (direct) TT
response code. But the response can also be done indirectly by another node
using the global TT state. To avoid such inconsistency states reported in
the original fix, also avoid sending empty VLANs for replies from the
global TT state.
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tt: fix negative last_changeset_len
batadv_piv_tt::last_changeset_len len was declared as s16, but the field is
never intended to hold a negative value. When a value greater than 32767 is
assigned, it wraps to a negative signed integer.
In batadv_send_my_tt_response(), last_changeset_len is temporarily widened
to s32. The incorrectly negative s16 value propagates into the s32, causing
batadv_tt_prepare_tvlv_local_data() to allocate a full sized buffer but
populates only a small portion of it with the collected changeset. All
remaining bits are kept uninitialized.
Using an u16 avoids this type confusion and ensures that no (negative) sign
extension is performed in batadv_send_my_tt_response().
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tt: fix negative tt_buff_len
batadv_orig_node::tt_buff_len was declared as s16, but the field is never
intended to hold a negative value. When a value greater than 32767 is
assigned, it wraps to a negative signed integer.
In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to
s32. The incorrectly negative s16 value propagates into the s32, causing
batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but
populates only a small portion of it with the collected changeset. All
remaining bits are kept uninitialized.
Using an u16 avoids this type confusion and ensures that no (negative) sign
extension is performed in batadv_send_other_tt_response().
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) reject implausible blackbox record_count
adm1266_nvmem_read_blackbox() loops over a record_count that comes
straight from byte 3 of the BLACKBOX_INFO response. The destination
buffer is data->dev_mem, sized for the nvmem cell's declared 2048
bytes (ADM1266_BLACKBOX_MAX_RECORDS * ADM1266_BLACKBOX_SIZE = 32 * 64).
A device that reports a record_count greater than 32 -- whether due
to firmware bugs, bus corruption, or a non-responsive slave returning
0xff -- would walk read_buff past the end of the dev_mem allocation
on the trailing iterations.
Cap record_count at ADM1266_BLACKBOX_MAX_RECORDS (introduced here)
before entering the loop and return -EIO on any larger value, so a
malformed BLACKBOX_INFO response cannot drive the loop out of bounds.
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer
adm1266_pmbus_block_xfer() sets up the read transaction with
.buf = data->read_buf,
.len = ADM1266_PMBUS_BLOCK_MAX + 2,
but read_buf in struct adm1266_data is declared as
u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1];
For a max-length block response (length byte = 255 + up to 1 PEC
byte), the i2c controller is told to write 257 bytes into a 256-byte
buffer, putting one byte past the end of read_buf. The same response
also makes the subsequent PEC compare
if (crc != msgs[1].buf[msgs[1].buf[0] + 1])
read a byte beyond the array.
Bump the read_buf declaration to ADM1266_PMBUS_BLOCK_MAX + 2 so the
buffer can hold the length byte, up to 255 payload bytes, and the PEC
byte the i2c_msg length already accounts for.
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
adm1266_pmbus_block_xfer() copies the device-supplied block payload
into the caller-provided buffer using the device-supplied length:
memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]);
The helper does not know how large data_r is and trusts the device to
return at most one record's worth of bytes. adm1266_nvmem_read_blackbox()
violates that contract: it advances read_buff inside data->dev_mem in
ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to
write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns
more than 64 bytes on the trailing record (read_buff offset 1984 in
the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes
before the post-call
if (ret != ADM1266_BLACKBOX_SIZE)
return -EIO;
can reject the response.
Contain the fix in the caller without changing the helper signature:
read each record into a 255-byte local bounce buffer that matches the
helper's maximum output, validate the returned length, and only then
copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.