In the Linux kernel, the following vulnerability has been resolved:
dm: clear cloned request bio pointer when last clone bio completes
Stale rq->bio values have been observed to cause double-initialization of
cloned bios in request-based device-mapper targets, leading to
use-after-free and double-free scenarios.
One such case occurs when using dm-multipath on top of a PCIe NVMe
namespace, where cloned request bios are freed during
blk_complete_request(), but rq->bio is left intact. Subsequent clone
teardown then attempts to free the same bios again via
blk_rq_unprep_clone().
The resulting double-free path looks like:
nvme_pci_complete_batch()
nvme_complete_batch()
blk_mq_end_request_batch()
blk_complete_request() // called on a DM clone request
bio_endio() // first free of all clone bios
...
rq->end_io() // end_clone_request()
dm_complete_request(tio->orig)
dm_softirq_done()
dm_done()
dm_end_request()
blk_rq_unprep_clone() // second free of clone bios
Fix this by clearing the clone request's bio pointer when the last cloned
bio completes, ensuring that later teardown paths do not attempt to free
already-released bios.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Add sanity check for OOB writes at silencing
At silencing the playback URB packets in the implicit fb mode before
the actual playback, we blindly assume that the received packets fit
with the buffer size. But when the setup in the capture stream
differs from the playback stream (e.g. due to the USB core limitation
of max packet size), such an inconsistency may lead to OOB writes to
the buffer, resulting in a crash.
For addressing it, add a sanity check of the transfer buffer size at
prepare_silent_urb(), and stop the data copy if the received data
overflows. Also, report back the transfer error properly from there,
too.
Note that this doesn't fix the root cause of the playback error
itself, but this merely covers the kernel Oops.
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Add bounds check on pat_index to prevent OOB kernel read in madvise
When user provides a bogus pat_index value through the madvise IOCTL, the
xe_pat_index_get_coh_mode() function performs an array access without
validating bounds. This allows a malicious user to trigger an out-of-bounds
kernel read from the xe->pat.table array.
The vulnerability exists because the validation in madvise_args_are_sane()
directly calls xe_pat_index_get_coh_mode(xe, args->pat_index.val) without
first checking if pat_index is within [0, xe->pat.n_entries).
Although xe_pat_index_get_coh_mode() has a WARN_ON to catch this in debug
builds, it still performs the unsafe array access in production kernels.
v2(Matthew Auld)
- Using array_index_nospec() to mitigate spectre attacks when the value
is used
v3(Matthew Auld)
- Put the declarations at the start of the block
(cherry picked from commit 944a3329b05510d55c69c2ef455136e2fc02de29)
In the Linux kernel, the following vulnerability has been resolved:
mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate()
Although it is guided that `#mbox-cells` must be at least 1, there are
many instances of `#mbox-cells = <0>;` in the device tree. If that is
the case and the corresponding mailbox controller does not provide
`fw_xlate` and of_xlate` function pointers, `fw_mbox_index_xlate()` will
be used by default and out-of-bounds accesses could occur due to lack of
bounds check in that function.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/ionic: Fix potential NULL pointer dereference in ionic_query_port
The function ionic_query_port() calls ib_device_get_netdev() without
checking the return value which could lead to NULL pointer dereference,
Fix it by checking the return value and return -ENODEV if the 'ndev' is
NULL.
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: ec_bhf: Fix dma_free_coherent() dma handle
dma_free_coherent() in error path takes priv->rx_buf.alloc_len as
the dma handle. This would lead to improper unmapping of the buffer.
Change the dma handle to priv->rx_buf.alloc_phys.
In the Linux kernel, the following vulnerability has been resolved:
drm/atmel-hlcdc: fix memory leak from the atomic_destroy_state callback
After several commits, the slab memory increases. Some drm_crtc_commit
objects are not freed. The atomic_destroy_state callback only put the
framebuffer. Use the __drm_atomic_helper_plane_destroy_state() function
to put all the objects that are no longer needed.
It has been seen after hours of usage of a graphics application or using
kmemleak:
unreferenced object 0xc63a6580 (size 64):
comm "egt_basic", pid 171, jiffies 4294940784
hex dump (first 32 bytes):
40 50 34 c5 01 00 00 00 ff ff ff ff 8c 65 3a c6 @P4..........e:.
8c 65 3a c6 ff ff ff ff 98 65 3a c6 98 65 3a c6 .e:......e:..e:.
backtrace (crc c25aa925):
kmemleak_alloc+0x34/0x3c
__kmalloc_cache_noprof+0x150/0x1a4
drm_atomic_helper_setup_commit+0x1e8/0x7bc
drm_atomic_helper_commit+0x3c/0x15c
drm_atomic_commit+0xc0/0xf4
drm_atomic_helper_set_config+0x84/0xb8
drm_mode_setcrtc+0x32c/0x810
drm_ioctl+0x20c/0x488
sys_ioctl+0x14c/0xc20
ret_fast_syscall+0x0/0x54
In the Linux kernel, the following vulnerability has been resolved:
media: mtk-mdp: Fix a reference leak bug in mtk_mdp_remove()
In mtk_mdp_probe(), vpu_get_plat_device() increases the reference
count of the returned platform device. Add platform_device_put()
to prevent reference leak.
In the Linux kernel, the following vulnerability has been resolved:
md-cluster: fix NULL pointer dereference in process_metadata_update
The function process_metadata_update() blindly dereferences the 'thread'
pointer (acquired via rcu_dereference_protected) within the wait_event()
macro.
While the code comment states "daemon thread must exist", there is a valid
race condition window during the MD array startup sequence (md_run):
1. bitmap_load() is called, which invokes md_cluster_ops->join().
2. join() starts the "cluster_recv" thread (recv_daemon).
3. At this point, recv_daemon is active and processing messages.
4. However, mddev->thread (the main MD thread) is not initialized until
later in md_run().
If a METADATA_UPDATED message is received from a remote node during this
specific window, process_metadata_update() will be called while
mddev->thread is still NULL, leading to a kernel panic.
To fix this, we must validate the 'thread' pointer. If it is NULL, we
release the held lock (no_new_dev_lockres) and return early, safely
ignoring the update request as the array is not yet fully ready to
process it.