In the Linux kernel, the following vulnerability has been resolved:
erofs: fix metabuf leak in inode xattr initialization
commit bb88e8da0025 ("erofs: use meta buffers for xattr operations")
converted xattr operations to use on-stack erofs_buf instances.
erofs_init_inode_xattrs() uses such a metabuf while reading the inline
xattr header and shared xattr id array.
Some error paths after erofs_read_metabuf() leave through out_unlock
without dropping the metabuf, so the folio reference can leak.
Consolidate the cleanup at out_unlock. erofs_put_metabuf() is a
no-op if no folio has been acquired, and this keeps all paths after
taking EROFS_I_BL_XATTR_BIT covered by a single cleanup site.
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:
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:
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: 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: 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:
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:
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 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.