In the Linux kernel, the following vulnerability has been resolved:
ksmbd: add chann_lock to protect ksmbd_chann_list xarray
ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in
multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del).
Adds rw_semaphore chann_lock to struct ksmbd_session and protects
all xa_load/xa_store/xa_erase accesses.
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos: vidi: use ctx->lock to protect struct vidi_context member variables related to memory alloc/free
Exynos Virtual Display driver performs memory alloc/free operations
without lock protection, which easily causes concurrency problem.
For example, use-after-free can occur in race scenario like this:
```
CPU0 CPU1 CPU2
---- ---- ----
vidi_connection_ioctl()
if (vidi->connection) // true
drm_edid = drm_edid_alloc(); // alloc drm_edid
...
ctx->raw_edid = drm_edid;
...
drm_mode_getconnector()
drm_helper_probe_single_connector_modes()
vidi_get_modes()
if (ctx->raw_edid) // true
drm_edid_dup(ctx->raw_edid);
if (!drm_edid) // false
...
vidi_connection_ioctl()
if (vidi->connection) // false
drm_edid_free(ctx->raw_edid); // free drm_edid
...
drm_edid_alloc(drm_edid->edid)
kmemdup(edid); // UAF!!
...
```
To prevent these vulns, at least in vidi_context, member variables related
to memory alloc/free should be protected with ctx->lock.
In the Linux kernel, the following vulnerability has been resolved:
smb: server: fix leak of active_num_conn in ksmbd_tcp_new_connection()
On kthread_run() failure in ksmbd_tcp_new_connection(), the transport is
freed via free_transport(), which does not decrement active_num_conn,
leaking this counter.
Replace free_transport() with ksmbd_tcp_disconnect().
In the Linux kernel, the following vulnerability has been resolved:
crypto: virtio - Add spinlock protection with virtqueue notification
When VM boots with one virtio-crypto PCI device and builtin backend,
run openssl benchmark command with multiple processes, such as
openssl speed -evp aes-128-cbc -engine afalg -seconds 10 -multi 32
openssl processes will hangup and there is error reported like this:
virtio_crypto virtio0: dataq.0:id 3 is not a head!
It seems that the data virtqueue need protection when it is handled
for virtio done notification. If the spinlock protection is added
in virtcrypto_done_task(), openssl benchmark with multiple processes
works well.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: split cached_fid bitfields to avoid shared-byte RMW races
is_open, has_lease and on_list are stored in the same bitfield byte in
struct cached_fid but are updated in different code paths that may run
concurrently. Bitfield assignments generate byte read–modify–write
operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can
restore stale values of the others.
A possible interleaving is:
CPU1: load old byte (has_lease=1, on_list=1)
CPU2: clear both flags (store 0)
CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits
To avoid this class of races, convert these flags to separate bool
fields.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths
The problem occurs when a signed request fails smb2 signature verification
check. In __process_request(), if check_sign_req() returns an error,
set_smb2_rsp_status(work, STATUS_ACCESS_DENIED) is called.
set_smb2_rsp_status() set work->next_smb2_rcv_hdr_off as zero. By resetting
next_smb2_rcv_hdr_off to zero, the pointer to the next command in the chain
is lost. Consequently, is_chained_smb2_message() continues to point to
the same request header instead of advancing. If the header's NextCommand
field is non-zero, the function returns true, causing __handle_ksmbd_work()
to repeatedly process the same failed request in an infinite loop.
This results in the kernel log being flooded with "bad smb2 signature"
messages and high CPU usage.
This patch fixes the issue by changing the return value from
SERVER_HANDLER_CONTINUE to SERVER_HANDLER_ABORT. This ensures that
the processing loop terminates immediately rather than attempting to
continue from an invalidated offset.
In the Linux kernel, the following vulnerability has been resolved:
bus: fsl-mc: fix use-after-free in driver_override_show()
The driver_override_show() function reads the driver_override string
without holding the device_lock. However, driver_override_store() uses
driver_set_override(), which modifies and frees the string while holding
the device_lock.
This can result in a concurrent use-after-free if the string is freed
by the store function while being read by the show function.
Fix this by holding the device_lock around the read operation.
In the Linux kernel, the following vulnerability has been resolved:
crypto: omap - Allocate OMAP_CRYPTO_FORCE_COPY scatterlists correctly
The existing allocation of scatterlists in omap_crypto_copy_sg_lists()
was allocating an array of scatterlist pointers, not scatterlist objects,
resulting in a 4x too small allocation.
Use sizeof(*new_sg) to get the correct object size.
In the Linux kernel, the following vulnerability has been resolved:
PCI: endpoint: Avoid creating sub-groups asynchronously
The asynchronous creation of sub-groups by a delayed work could lead to a
NULL pointer dereference when the driver directory is removed before the
work completes.
The crash can be easily reproduced with the following commands:
# cd /sys/kernel/config/pci_ep/functions/pci_epf_test
# for i in {1..20}; do mkdir test && rmdir test; done
BUG: kernel NULL pointer dereference, address: 0000000000000088
...
Call Trace:
configfs_register_group+0x3d/0x190
pci_epf_cfs_work+0x41/0x110
process_one_work+0x18f/0x350
worker_thread+0x25a/0x3a0
Fix this issue by using configfs_add_default_group() API which does not
have the deadlock problem as configfs_register_group() and does not require
the delayed work handler.
[mani: slightly reworded the description and added stable list]
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: fix slab-out-of-bounds in rtl8xxxu_sta_add
The driver does not set hw->sta_data_size, which causes mac80211 to
allocate insufficient space for driver private station data in
__sta_info_alloc(). When rtl8xxxu_sta_add() accesses members of
struct rtl8xxxu_sta_info through sta->drv_priv, this results in a
slab-out-of-bounds write.
KASAN report on RISC-V (VisionFive 2) with RTL8192EU adapter:
BUG: KASAN: slab-out-of-bounds in rtl8xxxu_sta_add+0x31c/0x346
Write of size 8 at addr ffffffd6d3e9ae88 by task kworker/u16:0/12
Set hw->sta_data_size to sizeof(struct rtl8xxxu_sta_info) during
probe, similar to how hw->vif_data_size is configured. This ensures
mac80211 allocates sufficient space for the driver's per-station
private data.
Tested on StarFive VisionFive 2 v1.2A board.