KVM: nVMX: Reset MMU back to the root MMU if loading L2 state fails for !VM-Entry
In the Linux kernel, the following vulnerability has been resolved:
KVM: nVMX: Reset MMU back to the root MMU if loading L2 state fails for !VM-Entry
Reset the vCPU's MMU pointer back to the root MMU if loading L2 state fails
in the "not from VM-Entry" case, i.e. when emulating RSM or handling
KVM_SET_NESTED_STATE. Failure to unwind the MMU pointer results in KVM
trying to run L1 with a nested MMU, and is especially problematic if the
vCPU manages to free its nested state before the VM crashes. Constructing
the root for a nested EPT MMU goes through vmcs12, which is dynamically
allocated/freed when nVMX is enabled/disabled. And so if the
fsnotify: prevent mark additions during connector teardown
In the Linux kernel, the following vulnerability has been resolved:
fsnotify: prevent mark additions during connector teardown
fsnotify_destroy_marks() keeps a reference to its current mark while it
drops conn->lock to destroy the mark. This stabilizes the forward-walk
cursor, but does not prevent a new mark from being inserted before it.
For example, an inotify watch re-added after IN_IGNORED sorts before the
old, detached mark for the same group. The walk can miss the replacement
and then detach the entire connector from the object.
The replacement is still on its group's marks_list and, for inotify, in
the watch IDR. The group mutex no
In the Linux kernel, the following vulnerability has been resolved:
ext4: free the sbi after a grace period
ext4_get_link() follows a symlink that keeps its target in a data block
in rcu pathwalk mode with ext4_getblk(EXT4_GET_BLOCKS_CACHED_NOWAIT).
That reads s_mount_state in the ASSERT() of ext4_getblk() and again in
ext4_es_lookup_extent(), and the lookup bumps the extent status hit or
miss counter, all through sb->s_fs_info.
ext4_put_super() destroys those counters, clears sb->s_fs_info and frees
the sbi without waiting for a grace period. A pathwalk that is still in
ext4_get_link() when the last reference to the mount goes away then
d
eventfs: Free the eventfs_inode after an rcu grace period too
In the Linux kernel, the following vulnerability has been resolved:
eventfs: Free the eventfs_inode after an rcu grace period too
tracefs_d_revalidate() reads ->is_freed of the eventfs_inode that
dentry->d_fsdata points to, and ->d_revalidate() is called in rcu
pathwalk mode with nothing but rcu_read_lock() held. The dentry itself
stays around for such a walker, but tracefs_d_release() drops its
reference to the eventfs_inode when the dentry is killed, and
release_ei() then frees it after a grace period of eventfs_srcu. An
SRCU grace period doesn't wait for rcu_read_lock() sections, so the
walker can read an eventfs_inode that is already go
ipc: drop the mqueue mount with kern_unmount() on setup failure
In the Linux kernel, the following vulnerability has been resolved:
ipc: drop the mqueue mount with kern_unmount() on setup failure
mq_init_ns() creates the mqueue mount with fc_mount_longterm(), so its
->mnt_ns is MNT_NS_INTERNAL. When setting up the mqueue or ipc sysctls
or msg_init_ns() fails afterwards, create_ipc_ns() drops it with a plain
mntput(). With ->mnt_ns set that takes the fast path of
mntput_no_expire(). The count drops to zero and nothing ever kills the
mount, so the mount and the mqueue superblock are leaked.
Commit dc55e35f9e81 ("ipc: Store mqueue sysctls in the ipc namespace")
added the first failure path after mq_init_n
In the Linux kernel, the following vulnerability has been resolved:
ntfs3: free the sbi after a grace period
If the "nocase" mount option ntfs3 uses custom hash and dentry compare
functions. Both access ntfs3 superblock private information in rcu
pathwalk. ntfs_put_super() and ntfs3_kill_sb() drop the info without any
rcu delay. A lookup that's still inside the filesystem when the last
reference to the mount is dropped causes a UAF. With a pathwalk held up
in ntfs_d_hash() while the last reference to the mount goes away:
BUG: KASAN: slab-use-after-free in ntfs_nls_to_utf16+0x752/0x940
Read of size 8 at addr ff1100010453c850 by task wal
namespace: a mount that copy_tree() leaves out can't take over a lock
In the Linux kernel, the following vulnerability has been resolved:
namespace: a mount that copy_tree() leaves out can't take over a lock
Since commit c62a4766937e ("move_mount: transfer MNT_LOCKED") a mount
can be moved beneath a locked mount. The lock moves from the old cover
to the new mount which takes over the job of hiding what's under it and
the old cover can be unmounted. That works as long as the new mount
stays. But the caller picks the new mount and copy_tree() leaves a
mount of a mount namespace file out of every copy made without
CL_COPY_MNT_NS_FILE, together with everything mounted on it, and never
looks at MNT_LOCKED. unshare
In the Linux kernel, the following vulnerability has been resolved:
futex: Fix mm reuse handling for FUT_OFF_MMSHARED
A FUT_OFF_MMSHARED futex is a shared futex that refers to an MM.
It is possible for a process to wait on a shared futex with a different MM
because a FUT_OFF_INODE waiter can be requeued onto a FUT_OFF_MMSHARED
futex by another process.
This can cause FUT_OFF_MMSHARED waiters on a freed MM to consume
wakeups intended for a newly allocated MM at the same address.
Fix it by keying FUT_OFF_MMSHARED using a unique 64-bit per-MM ID.
Leave private futexes as before to avoid influencing the performance of the
hotpath.
(Multi-thre
In the Linux kernel, the following vulnerability has been resolved:
mshv_vtl: Check per-CPU register page before mmap
Register-page setup is optional for each CPU. If allocation or
registration fails, mshv_vtl_configure_reg_page() warns and leaves that
CPU's reg_page NULL, but initial context setup continues successfully.
Meanwhile, successful setup on another CPU sets the global
mshv_has_reg_page flag.
mshv_vtl_fault() checks this global flag before selecting the requested
CPU's register page. With mixed setup results across online CPUs, the
check passes even for a CPU with no register page, reaching
get_page(NULL) when userspace faults i
net/sched: fix use-after-free in __tcf_action_put()
In the Linux kernel, the following vulnerability has been resolved:
net/sched: fix use-after-free in __tcf_action_put()
__tcf_action_put() decrements the reference count before decrementing the
binding count. Another thread can free the action between these operations,
causing the binding-count update to access freed memory. KASAN reports it
as:
BUG: KASAN: slab-use-after-free in __tcf_action_put+0x327/0x340
Write of size 4 at addr ff11000000d46420 by task tc-put-pause/64
Hold the action IDR mutex across both counter updates and IDR removal,
keeping cleanup outside the lock.
net: rds: fix uninitialized trans dereference in CM event handler
In the Linux kernel, the following vulnerability has been resolved:
net: rds: fix uninitialized trans dereference in CM event handler
rds_rdma_cm_event_handler_cmn() assigns trans only when the RDMA
device is an InfiniBand CA (RDMA_NODE_IB_CA). On any other device
type, e.g. an iWARP RNIC such as siw, trans stays uninitialized, but
the event switch dereferences it: unconditionally in the
RDMA_CM_EVENT_CONNECT_REQUEST case via trans->cm_handle_connect(),
and (with a connection context) in the ROUTE_RESOLVED and
ESTABLISHED cases.
An RDS listener on an iWARP device therefore crashes the kernel as
soon as a connect request arrives: with CONF
sctp: revalidate output stream after association connect wait
In the Linux kernel, the following vulnerability has been resolved:
sctp: revalidate output stream after association connect wait
When message interleaving is enabled, the first send waits for association
establishment before building its data chunks. The wait drops the socket
lock, and handshake processing can reduce the output stream count to the
peer-advertised inbound stream count. sctp_stream_init() then frees the
extension of every removed stream.
The sender resumes with the stream that it checked before the wait. If the
peer removed that stream, sctp_outq_tail() later dereferences its NULL
extension. Fatal-oops policies then pan
spi: imx: fix slab corruption from undersized DMA bounce buffers
In the Linux kernel, the following vulnerability has been resolved:
spi: imx: fix slab corruption from undersized DMA bounce buffers
Since commit faa8e404ad8e ("spi: imx: support dynamic burst length for
ECSPI DMA mode"), the driver allocates its private DMA TX/RX buffers
with kzalloc(dma_len), where dma_len is only rounded up to 4 bytes, but
maps, syncs and unmaps them with DMA_CACHE_ALIGNED_LEN(dma_len), i.e.
rounded up to the cache line size. As a result, the DMA API operates on
memory beyond the end of the allocation.
This was observed on a custom i.MX8MP platform with an mcp251xfd CAN
controller under heavy RPMSG load, as a series of
tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields
In the Linux kernel, the following vulnerability has been resolved:
tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields
In check_synth_field(), when a synthetic event field is a stacktrace
(field->is_stack) and the histogram field is not a "long[" stacktrace
array, validation falls through to the generic size and signedness
comparison.
Because parse_synth_field() sets a stacktrace field's type to
"__data_loc unsigned long[]", its size is sizeof(u64) and
synth_field_signed() marks it as signed. Consequently, any 8-byte
signed scalar histogram field passes the fallback check, and its scalar
value is subsequently
gpio: shared: fix use-after-free bug when adding shared proxies
In the Linux kernel, the following vulnerability has been resolved:
gpio: shared: fix use-after-free bug when adding shared proxies
The GPIO lookup table can stay alive for longer than the kobject whose
name string's address we're assigning to lookup->dev_id. Fix a potential
UAF by duplicating the string.
i2c: viai2c-wmt: Fix clock leak in wmt_i2c_probe()
In the Linux kernel, the following vulnerability has been resolved:
i2c: viai2c-wmt: Fix clock leak in wmt_i2c_probe()
In wmt_i2c_probe(), i2c->clk is acquired using of_clk_get(). If any
subsequent operation fails or when the module is unloaded, the clock
reference count is never decremented via clk_put(), leading to a
resource leak.
Switch to devm_clk_get() so that the clock is automatically managed
and released.
ring-buffer: Do not show buffer_meta for CPUs without a buffer
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Do not show buffer_meta for CPUs without a buffer
The per_cpu/cpuN/buffer_meta files are created for every possible CPU,
but buffer->buffers[cpu] is only allocated once that CPU comes online.
Reading the file of a CPU that never came online dereferences a NULL
cpu_buffer in rbm_start().
Fail the open with -ENODEV when the CPU has no buffer, as the other
per CPU ring buffer interfaces do.
ring-buffer: Fix the sub-buffer array base in rb_meta_subbuf_idx()
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Fix the sub-buffer array base in rb_meta_subbuf_idx()
On a persistent ring buffer, rb_meta_subbuf_idx() can return an index one
sub-buffer too high. rb_setup_ids_meta_page() then fills subbuf_ids[]
shifted by one and leaves subbuf_ids[0] NULL, which __rb_map_vma()
dereferences when userspace maps trace_pipe_raw. rb_update_meta_reader()
writes two such indices into meta->buffers[], which rb_cpu_meta_valid()
would reject on the next boot, discarding the previous boot's trace.
A CPU's sub-buffer array starts after its meta header and the nr_subbufs
integers tha
ring-buffer: Fix false warning in ring_buffer_map_get_reader()
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Fix false warning in ring_buffer_map_get_reader()
The mmap reader can warn when it catches up with a writer that is still
committing events. rb_get_reader_page() returns NULL in this case, but
ring_buffer_map_get_reader() treats that result as an error.
The initial rb_per_cpu_empty() check filters out an empty buffer, but it
does not guarantee that the next reader page has committed data. Writers
do not take reader_lock and can advance commit_page before publishing the
committed length on the new page. rb_get_reader_page() can swap to that
page, catch up with
scsi: bsg: Pass reply_len to bsg_setup_queue() to fit UFS ARPMB replies
In the Linux kernel, the following vulnerability has been resolved:
scsi: bsg: Pass reply_len to bsg_setup_queue() to fit UFS ARPMB replies
bsg-lib allocates a 96-byte (SCSI_SENSE_BUFFERSIZE) reply buffer per
job, but struct ufs_rpmb_reply is 104 bytes: a 40-byte struct
ufs_bsg_reply followed by a 64-byte EHS. When an Advanced RPMB command
returns an EHS, ufshcd_advanced_rpmb_req_handler() copies it right after
the 40-byte header and writes 8 bytes past the end of the buffer.
Let each BSG transport pass its reply buffer size to bsg_setup_queue()
and have ufs_bsg request sizeof(struct ufs_rpmb_reply), so the full
reply reaches user space. O