| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Delay module ref count for "enable_event" trigger
Triggers are now delayed from freeing, but can still be triggered until
after the RCU grace period has ended. The freeing of the enable_event data
is put into the private_data_free() callback, but the put of the module
refcount is done immediately.
It is possible that if a module is removed that has an event that would
enable (or disable) it is still active, it can read the data of the module
after it is removed causing a use-after-free bug.
Move the trace_event_put_ref() that releases the module into the delayed
callback so that the module can not be removed until any reference to its
events are finished. |
| In the Linux kernel, the following vulnerability has been resolved:
ublk: wait on ublk_dev_ready() instead of ub->completion
ub->completion is only re-armed by a successful START_USER_RECOVERY. If
the ublk server sends END_USER_RECOVERY without one - e.g. its START
failed with -EBUSY and the error was ignored - the wait is satisfied by
the stale completion of the previous recovery cycle, and the device is
marked LIVE and the requeue list kicked while the FETCH stream is still
running and ubq->canceling is still set. The kick redispatches a
previously requeued request, __ublk_queue_rq_common() sees ->canceling
and parks it again via __ublk_abort_rq(), and after the last FETCH
clears ->canceling nothing ever kicks the requeue list again: the
request is stranded there while holding its tag. If it is the flush
machinery's flush_rq, every subsequent fsync piles up in uninterruptible
sleep and teardown hangs on tag draining. This matches a report of a
lost PREFLUSH with ext4 on top of ublk after daemon crash recovery.
ub->completion is an edge-triggered latch used as a proxy for the level
condition "every queue has fetched all I/O commands", which can regress
(F_BATCH's UNPREP, daemon death) and whose re-arm can be skipped. Drop
it and wait on the real condition instead: the new helper
ublk_wait_dev_ready_and_lock() waits on ublk_dev_ready() via
wait_var_event_interruptible(), woken from ublk_mark_io_ready(), then
re-checks it under ub->mutex, waiting again on regression, and returns
with the mutex held and readiness guaranteed.
Readiness becomes true in the same ub->mutex critical section that
clears the last queue's ->canceling, so END_USER_RECOVERY marks the
device LIVE and kicks the requeue list strictly after ->canceling
clears. The wait stays interruptible, so a server whose daemon died can
still be signalled out. For ublk_ctrl_start_dev() this replaces the
fail-fast -EINVAL on an F_BATCH ready->UNPREP regression with waiting
until the device is ready again. |
| In the Linux kernel, the following vulnerability has been resolved:
arm64: make huge_ptep_get handled unaligned addresses
huge_ptep_get() can be handed a virtual address pointing to the middle
of a contpmd/contpte mapped hugetlb folio (examples of callers are
pagemap_hugetlb_range, page_mapped_in_vma).
The arm64 helper rewalks the pgtables in find_num_contig to answer
whether the huge pte we have maps a contpmd or a contpte hugetlb folio,
and returns CONT_PMDS or CONT_PTES, so that it can collect a/d bits over
the contiguous ptes. We can falsely return CONT_PTES instead of
CONT_PMDS if the addr is not aligned. On systems where CONT_PTES !=
CONT_PMDS (meaning page size is 16K), we could collect excess A/D bit
state, meaning extra work for the kernel. Even worse, we may iterate
beyond the PTE table and dereference a garbage ptep pointer to access
physical memory we don't own. Since the ptep pointer is a linear map
address, we may run off the end of the linear map or into a hole,
dereference a VA not mapped into the kernel pgtables and cause kernel
panic.
Fix this by aligning the pmdp pointer down to a contpmd base before
checking equality with the passed huge pte pointer, to correctly answer
whether the huge pte is the base of a contpmd block. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix stale skb->sk reference on subflow close
The backlog list is updated by mptcp_data_ready() under
mptcp_data_lock(). The cleanup of backlog references to a closing
subflow, however, was performed in mptcp_close_ssk(), before
__mptcp_close_ssk() acquires the ssk lock, and while holding neither
the ssk lock nor mptcp_data_lock().
Because that traversal ran without mptcp_data_lock(), concurrent softirq
RX processing on another CPU (subflow_data_ready() -> mptcp_data_ready()
-> __mptcp_add_backlog(), under mptcp_data_lock()) could add a backlog
entry referencing the ssk while the cleanup loop was in progress. Such
an entry could be missed by the cleanup, or the concurrent list update
could corrupt the traversal, leaving skb->sk pointing at the ssk after
it is freed.
A later mptcp_backlog_purge() then dereferences the stale pointer,
triggering a warning in inet_sock_destruct() (ssk->sk_rmem_alloc != 0)
followed by a use-after-free in mptcp_backlog_purge().
Fix this by moving the backlog cleanup into __mptcp_close_ssk(), after
subflow->closing is set to 1 and while the ssk lock is still held,
serialized under mptcp_data_lock(). The cleanup runs only on the push
path (MPTCP_CF_PUSH), where backlog references accumulate; on other
teardown paths the caller already handles cleanup.
With subflow->closing set and mptcp_data_lock() held across the purge,
any concurrent mptcp_data_ready() either completes its enqueue before
the purge runs and is caught, or observes closing=1 and bails out. Once
mptcp_data_unlock() is reached, no new skb referencing the ssk can be
enqueued, so the cleanup is exhaustive.
Remove the unprotected traversal from mptcp_close_ssk() entirely. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/page_vma_mapped: fix device-private PMD handling
Commit 65edfda6f3f2 ("mm/rmap: extend rmap and migration support
device-private entries") introduced the concept of device-private PMD
entries, but did not correctly update the rmap walk code to account for
them.
As a result, when page_vma_mapped_walk() encounters device-private PMD
entries, it takes no action other than to acquire the PMD lock and exit.
However this is highly problematic for two reasons - firstly, device
private entries possess a PFN so check_pmd() needs to be called to ensure
an overlapping PFN range.
Secondly, and more importantly, if PVMW_MIGRATION is set the caller
assumes the returned entry is a migration entry, resulting in memory
corruption when the caller tries to interpret the device private entry as
such.
In addition, commit 146287290023 ("mm/huge_memory: implement
device-private THP splitting") allowed device private PMDs to be split
like THP mappings, but again did not update this code path.
As a result, we might race a PMD split prior to acquiring the PMD lock.
This patch addresses all of these issues by invoking check_pmd(), ensuring
PMVW_MIGRATION is not set and checks whether a split raced us we do for
PMD THP and migration entries.
Instead of checking for a subset of the cases after taking the pmd_lock(),
put device-private along with pmd_trans_huge() and
pmd_is_migration_entry(). Also remove thp_migration_supported() as it is
already guarded by pmd_is_migration_entry().
[[email protected]: fix Raspberry Pi 1 build, per David] |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: avoid auth_enable sysctl UAF during netns teardown
proc_sctp_do_auth() updates the SCTP control socket after changing
net.sctp.auth_enable. The handler gets the per-net SCTP state from
ctl->data, so an already opened sysctl file can still target a network
namespace while that namespace is being torn down.
SCTP previously registered its per-net sysctls from sctp_defaults_init(),
while the control socket is created later from sctp_ctrlsock_init(). This
exposed a window during initialization where auth_enable was writable
before net->sctp.ctl_sock existed, and a teardown window where auth_enable
stayed writable after inet_ctl_sock_destroy() had released the control
socket.
Move the per-net SCTP sysctl registration into sctp_ctrlsock_init() after
sctp_ctl_sock_init() succeeds, and unregister the sysctl table before
destroying the control socket in sctp_ctrlsock_exit(). If sysctl
registration fails after the control socket was created, destroy the
control socket in the same init path.
Make sctp_sysctl_net_unregister() tolerate a missing header and clear the
saved pointer so init-error and exit paths can safely share the unregister
helper. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: close UDP tunnel sockets during netns teardown
proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when
net.sctp.udp_port is set, and stops/restarts them when the sysctl value
changes. The netns exit path does not stop these sockets, so a namespace
can be torn down while its SCTP UDP tunnel sockets are still installed.
Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering
the per-net sysctl table. This prevents new sysctl writes from racing in
while the sockets are being released, and closes the sockets before the
control socket is destroyed. |
| In the Linux kernel, the following vulnerability has been resolved:
ceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps()
ceph_handle_caps() reads snap_trace_len from the wire-format
ceph_mds_caps header and uses it unconditionally to build a fake
end pointer (snaptrace + snaptrace_len) that is later handed to
ceph_update_snap_trace() in the CEPH_CAP_OP_IMPORT case:
snaptrace = h + 1;
snaptrace_len = le32_to_cpu(h->snap_trace_len);
p = snaptrace + snaptrace_len;
...
case CEPH_CAP_OP_IMPORT:
if (snaptrace_len) {
...
if (ceph_update_snap_trace(mdsc, snaptrace,
snaptrace + snaptrace_len,
false, &realm)) { ... }
ceph_update_snap_trace() then decodes a struct ceph_mds_snap_realm
from snaptrace using ceph_decode_need(&p, e, sizeof(*ri), bad)
with the attacker-supplied fake end e == snaptrace + snaptrace_len.
With snaptrace_len == 0xFFFFFFFF the bound check is trivially
satisfied, ri = p reads sizeof(struct ceph_mds_snap_realm) past
the legitimate msg->front buffer, and ri->num_snaps /
ri->num_prior_parent_snaps then drive further out-of-bounds
reads of the encoded snap arrays.
The eleven msg_version >= 2 .. msg_version >= 12 decoder blocks
above the op switch each catch this OOB through their
ceph_decode_*_safe() / ceph_decode_need() helpers, but they sit
behind a hdr.version-gated if, so a malicious or compromised
MDS that sets msg->hdr.version = 1 reaches the IMPORT path with
no version-gated decoder having validated snap_trace_len. The
shape has been present since ceph_handle_caps() was introduced.
Validate snap_trace_len against the message front buffer before
consuming it, using the canonical ceph_decode_need() / ceph_has_room()
helper. The helper bounds the length with subtraction (n <= end - p,
guarded by end >= p) rather than pointer addition, so it is wrap-safe
for the attacker-controlled u32 length on 32-bit builds where
p + snap_trace_len could overflow the address space. This matches the
rest of the ceph decode path (e.g. the pool_ns_len check a few lines
below), and the existing goto bad cleanup already covers this exit
path. |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE
__decode_pg_temp() decodes an user-controlled length but only rejects
values large enough to overflow the allocation; it does not bound it to
CEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and
apply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size
on-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends
an OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack
out-of-bounds write.
An OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer
entries at decode time. The bound is well below the old overflow threshold, so
it also covers the allocation-size overflow the previous check guarded against.
BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds
Write of size 4 ... by task exploit
kasan_report (mm/kasan/report.c:595)
ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)
calc_target (net/ceph/osd_client.c:1638)
__submit_request (net/ceph/osd_client.c:2394)
ceph_osdc_start_request (net/ceph/osd_client.c:2490)
ceph_osdc_call (net/ceph/osd_client.c:5164)
rbd_dev_image_probe (drivers/block/rbd.c:6899)
do_rbd_add (drivers/block/rbd.c:7138)
...
kernel BUG at net/ceph/osdmap.c:2670!
[ idryomov: do the same in __decode_pg_upmap_items() ] |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: Fix multiplication overflow in decode_new_up_state_weight()
If a message of type CEPH_MSG_OSD_MAP contains a (maliciously) corrupted
osdmap, out-of-bounds memory accesses may occur in
decode_new_up_state_weight(). This happens because the bounds check for
the new_state part is based on calculating its length depending on a len
value read from the incoming message. This calculation may overflow
leading to an incorrect bounds check. Subsequently, out-of-bounds reads
may occur when decoding this part.
This patch switches the multiplication to use check_mul_overflow() to
abort processing the osdmap if an overflow occurred. Therefore,
osdmaps/messages containing large values for len that result in a
multiplication overflow are treated as invalid.
[ idryomov: rename new_state_len -> new_state_item_size, formatting ] |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: guard missing CRUSH type name lookup
Localized read selection can walk a parent bucket whose name exists in
the CRUSH map while its type has no matching entry in type_names.
get_immediate_parent() then dereferences a NULL type_cn and passes an
invalid pointer into strcmp(), causing a null-ptr-deref.
Skip such malformed parent buckets unless both the bucket name and type
name metadata are present. This keeps malformed hierarchy data from
crashing locality lookup and safely falls back to "not local".
[ idryomov: add WARN_ON_ONCE ] |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: refresh auth->authorizer_buf{,_len} after authorizer update
ceph_x_create_authorizer() caches au->buf->vec.iov_base and
au->buf->vec.iov_len in struct ceph_auth_handshake. These
cached values are then used by the messenger connect code when
sending the authorizer.
ceph_x_update_authorizer() can rebuild the authorizer when a newer
service ticket is available. If the rebuilt authorizer no longer
fits in the existing buffer, ceph_x_build_authorizer() drops its
reference to au->buf and allocates a new one. If this is the final
reference, ceph_buffer_put() frees the old ceph_buffer and its
vec.iov_base, but auth->authorizer_buf still points at that freed
memory.
A subsequent msgr1 reconnect can therefore queue the stale pointer
and trigger a KASAN slab-use-after-free in _copy_from_iter() while
tcp_sendmsg() copies the authorizer.
Refresh auth->authorizer_buf and auth->authorizer_buf_len after a
successful authorizer rebuild so the messenger sends the current
buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: Reject monmaps advertising zero monitors
A message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a
monitor to the client. This monmap contains information about the
existing monitors in the cluster. Currently, a monmap indicating that
there are zero monitors in the cluster is treated as valid. However, it
is impossible to have zero monitors in the cluster and still receive a
valid monmap from a monitor. Therefore, such a monmap must be corrupted
and should be treated as invalid. Furthermore, a monmap with a monitor
count of zero can subsequently crash the client when attempting to open
a session with a monitor in __open_session(). This happens because the
"BUG_ON(monc->monmap->num_mon < 1)" assertion in pick_new_mon() is
triggered.
This patch extends a check in ceph_monmap_decode() to also reject
arriving mon_maps with num_mon == 0 rather than only with
num_mon > CEPH_MAX_MON.
[ idryomov: drop "log output for unusual values of num_mon" part ] |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: reject zero bucket types in crush_decode
CRUSH bucket type 0 is reserved for devices. The mapper relies on
that invariant and uses type 0 to identify leaf devices.
If crush_decode() accepts a bucket with type 0, a malformed CRUSH map
can make the mapper treat a negative bucket ID as a device and pass it
to is_out(), which then indexes the OSD weight array with a negative
value.
Reject zero bucket types while decoding the CRUSH map so the invalid
state never reaches the mapper. |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: remove debugfs files before client teardown
ceph_destroy_client() tears down the monitor client before removing
the per-client debugfs files. A concurrent read of the monmap debugfs
file can enter monmap_show() after ceph_monc_stop() has freed
monc->monmap, triggering a use-after-free.
Remove the debugfs files before stopping the OSD and monitor clients.
debugfs_remove() drains active handlers and prevents new accesses, so
the debugfs callbacks can no longer race the rest of client teardown. |
| In the Linux kernel, the following vulnerability has been resolved:
amt: fix use-after-free in AMT delayed works
When an AMT device is removed, pending delayed works can still access
the freed amt_dev structure, which may result in kernel crashes or
memory corruption.
amt_dev_stop() cancels req_wq and discovery_wq with
cancel_delayed_work_sync(), but these works can be scheduled again
from event_wq after the cancellation. This allows delayed works to
access the freed amt_dev structure after the netdev has been released.
The following is a simple race scenario:
CPU0 CPU1
amt_dev_stop()
cancel_delayed_work_sync()
amt_event_work()
mod_delayed_work(req_wq)
free netdev
req_wq accesses freed amt_dev
Use disable_delayed_work_sync() in amt_dev_stop() to prevent req_wq and
discovery_wq from being queued again and wait for running work items
to complete.
The delayed works are disabled after initialization in
amt_newlink() and enabled only when the device is successfully opened.
This keeps the delayed work lifecycle synchronized with the lifetime
of the AMT device. |
| In the Linux kernel, the following vulnerability has been resolved:
fs: preserve ACL_DONT_CACHE state in forget_cached_acl()
The ACL_DONT_CACHE state is meant to be a constant state for the inode
for filesystems that want to opt out of posix acl caching.
Commit facd61053cff1 ("fuse: fixes after adapting to new posix acl api")
used this facility to opt out of posix acl caching for fuse inodes with
fuse server that does not negotiate FUSE_POSIX_ACL (fc->posix_acl).
The commit also takes care to gate the forget_all_cached_acls() call in
fuse_set_acl() on fc->posix_acl because there is no need for it, but
there are other placed in fuse code which call forget_all_cached_acls()
unconditional to fc->posix_acl and those cause the loss of the
ACL_DONT_CACHE state.
This is not only a functional bug. Properly timed, a get_acl() from this
fuse filesystem can return a stale cached value, as was observed in tests,
because set_acl() does not invalidate the unintentional acl cache.
We could fix this in fuse, but it actually makes no sense for the vfs
helper forget_cached_acl() to invalidate the ACL_DONT_CACHE state, so
let it not do that to fix fuse and future users of ACL_DONT_CACHE. |
| In the Linux kernel, the following vulnerability has been resolved:
fscrypt: Add missing superblock check in find_or_insert_direct_key()
The legacy 'fscrypt_direct_keys' table caches master keys that are used
by v1 encryption policies that have FSCRYPT_POLICY_FLAG_DIRECT_KEY.
It's just a global table for all filesystems (since the keys can be
provided by the legacy process-subscribed keyrings mechanism, which
makes it difficult to reuse super_block::s_master_keys).
The entries in it ('struct fscrypt_direct_key') do contain a super_block
pointer, though, for passing to fscrypt_destroy_inline_crypt_key() when
the last inode that references the key is evicted.
However, when finding the fscrypt_direct_key for an inode, we weren't
actually comparing the super_block pointer. As a result, inodes with
different super_blocks could point to the same fscrypt_direct_key. That
could extend the lifetime of a fscrypt_direct_key beyond the
super_block it points to, causing a use-after-free later.
Fix this by creating distinct fscrypt_direct_key structs for distinct
super_block structs.
Note that this problem doesn't exist in the v2 policy equivalent
("per-mode keys"), since the data structures there are per super_block. |
| In the Linux kernel, the following vulnerability has been resolved:
fscrypt: Avoid dynamic allocation in fscrypt_get_devices()
When a blk_crypto_key starts being used or is evicted, fs/crypto/ calls
fscrypt_get_devices() to get the filesystem's list of block devices,
then iterates over them and calls blk_crypto_config_supported(),
blk_crypto_start_using_key(), or blk_crypto_evict_key() on each one.
Currently, the block device pointers are placed in a dynamically
allocated array. This dynamic allocation is problematic because:
- It can fail, especially at the fscrypt_destroy_inline_crypt_key() call
site when it's invoked for inode eviction under direct reclaim.
- fscrypt_destroy_inline_crypt_key() doesn't handle the failure. It
just zeroizes and frees the blk_crypto_key without calling
blk_crypto_evict_key(). That causes a use-after-free.
For now, let's fix this in the straightforward and easily-backportable
way by switching to an on-stack array. Currently the fscrypt
multi-device functionality is used only by f2fs, which has a hardcoded
limit of 8 block devices. An on-stack array works fine for that.
(Of course, this solution won't scale up to large number of block
devices. For that we'd need a different solution, like moving the block
device iteration into the filesystem. Or in the case of btrfs, which
will only support blk-crypto-fallback, we should make it just call
blk-crypto-fallback directly, so the block devices won't be needed.) |
| In the Linux kernel, the following vulnerability has been resolved:
iomap: fix out-of-bounds bitmap_set() with zero-length range
ifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk
as (off + len - 1) >> i_blkbits. When off is 0 and len is 0, the
unsigned subtraction underflows to SIZE_MAX, producing a huge
last_blk and nr_blks value that causes bitmap_set() to write far
beyond the ifs->state allocation.
Regarding ifs_set_range_uptodate(), it is temporarily safe because len
cannot be passed in as 0. However, for ifs_set_range_dirty() this is
reachable from __iomap_write_end(): when copy_folio_from_iter_atomic()
returns 0 (e.g. user buffer fault) and the folio is already uptodate,
the guard at the top of __iomap_write_end() does not trigger because
!folio_test_uptodate() is false, and iomap_set_range_dirty() is called
with copied == 0.
Add a !len guard to both functions before the computation, so that a
zero-length range is a no-op. |
