| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
unicode: free the map after a grace period
generic_ci_d_hash() and generic_ci_d_compare() read sb->s_encoding and
dereference the unicode map while a pathwalk in rcu mode holds nothing
but rcu_read_lock(). The filesystems that use them, ext4, f2fs and
tmpfs, drop the map with utf8_unload() from ->put_super(), which runs
when the last reference to the mount goes away. A lookup that is still
inside such a filesystem at that point reads a freed map.
With a pathwalk held up in utf8_casefold_hash() while the last reference
to a casefolded tmpfs goes away:
BUG: KASAN: slab-use-after-free in utf8nlookup+0x74c/0x950
Read of size 8 at addr ff110001030fe658 by task walker/98
Call Trace:
<TASK>
utf8nlookup+0x74c/0x950
utf8byte+0x160/0x1560
utf8_casefold_hash+0x167/0x230
generic_ci_d_hash+0xdd/0x1c0
link_path_walk+0x11ad/0x1d30
path_lookupat+0x63/0xb00
filename_lookup+0x1f1/0x5b0
vfs_statx+0xd7/0x3b0
[...]
Allocated by task 94:
__kmalloc_cache_noprof+0x249/0x560
utf8_load+0x4e/0x570
shmem_parse_opt_casefold.isra.0+0x92/0x270
[...]
Freed by task 97:
kfree+0x1db/0x5b0
shmem_put_super+0x72/0x170
generic_shutdown_super+0x14c/0x530
kill_anon_super+0x3a/0x60
deactivate_locked_super+0x9c/0xf0
cleanup_mnt+0x9f/0x130
So far that has been hard to hit. umount(2) waits for a grace period
in namespace_unlock() before it drops the mount, so only a mount whose
last reference goes away elsewhere, like the close of a file or a chdir
out of a lazily unmounted directory, can race a walker. So it is
reachable.
Delay the free until a grace period has passed. The map and the data
table it holds a reference to then outlive any pathwalk that found the
superblock before the mount went away. The reference on the data table
module is dropped from the rcu callback as well. utf8-core is built in
whenever CONFIG_UNICODE is set, so there is no module exit that would
have to wait for the callbacks.
Overlayfs points the s_encoding of an overlay at the map of its first
layer without taking a reference of its own. That stays correct. The
layer is held by the overlay, so its map is dropped only after the
overlay is gone. |
| In the Linux kernel, the following vulnerability has been resolved:
watch_queue: Fix note pool publication race in watch_queue_set_size()
There is a race between watch_queue_set_size() and post_one_notification().
watch_queue_set_size() publishes wqueue->notes, notes_bitmap, nr_pages and
nr_notes with plain stores, and post_one_notification() reads them with
plain loads under a different lock, so nothing orders the four stores
against the poster's loads: depending on the build, notes can be stored
last (gcc 14 on x86-64 does this). Since keyctl_watch_key() lets a watch
attach to a queue before it is sized, post_one_notification() can already
be running on another CPU at that moment: it reads nr_notes > 0, passes
its bounds check, and then reads notes while it is still NULL,
dereferencing notes[0].
An unprivileged user triggers this reliably by watching one of its own
keys through a notification pipe and racing ioctl(IOC_WATCH_QUEUE_SET_SIZE)
on that pipe against keyctl(KEYCTL_SETPERM) on the key from another CPU,
triggering:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:post_one_notification.isra.0+0xa2/0x1e0
Call Trace:
__post_watch_notification+0x148/0x180
keyctl_setperm_key+0x119/0x130
do_syscall_64+0x108/0x4c0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Kernel panic - not syncing: Fatal exception in interrupt
Fix this by publishing nr_notes last with smp_store_release(), and by
reading it once with smp_load_acquire() in post_one_notification() before
the bitmap and the page array are touched. A poster that observes a
non-zero nr_notes then also observes the pool behind it; one that observes
zero drops the notification as before. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/kvm: Don't consume async #PF flags on a kernel #PF in NMI context
An async #PF "page not present" event arrives through the #PF vector,
and its reason sits in the per-CPU apf_reason.flags until
__kvm_handle_async_pf() reads and clears it. If an NMI arrives after
the event is injected and before the #PF handler reads the flags, and
the NMI handler itself takes a #PF, that fault reads and clears the
flags belonging to the #PF it interrupted. It then finds interrupts
disabled in the NMI context it interrupted, and panics:
Kernel panic - not syncing: Host injected async #PF in interrupt
disabled region
Call Trace:
<NMI>
panic+0x52/0x60
__kvm_handle_async_pf+0xb0/0xb0
exc_page_fault+0x71/0xb0
asm_exc_page_fault+0x27/0x30
RIP: 0010:__get_user_nocheck_8+0x6/0x20
perf_callchain_user+0x147/0x1a0
get_perf_callchain+0x12d/0x1c0
...
perf_event_nmi_handler+0x26/0x50
exc_nmi+0xe8/0x110
RIP: 0010:asm_exc_page_fault+0x0/0x30
</NMI>
The last RIP line shows the NMI landing on the first instruction of
the #PF entry. perf with user call chains takes such a fault: the
sampling NMI walks the user stack with __get_user(), which faults when
a saved frame pointer is not a valid user address or the walk runs off
the top of the stack. The same window exists when KVM, running as an
L1 hypervisor with DELIVERY_AS_PF_VMEXIT, reads the flags itself after
a #PF VM-exit.
The NMI entry code saves and restores CR2 for this nesting, but not the
async #PF reason. Andy Lutomirski described the race, with perf as the
example, when async #PF delivery was reworked in 2020 [1]. Saving and
clearing the flags across the NMI, next to CR2, was discussed there but
not merged.
Since that rework, Linux has stopped setting KVM_ASYNC_PF_SEND_ALWAYS,
so the host delivers "page not present" only for user mode faults and
a kernel-mode fault in NMI context (including kernel-mode #MC and #DB)
cannot be an async page fault. In that case, return without touching
the flags so that the interrupted handler finds them intact.
Tested on v7.3-rc5 in a 4-vCPU, 2 GiB guest restored from a snapshot
whose memory is served on demand through userfaultfd, so that reading
it back takes async #PFs, while every thread samples hardware cycles
with user call chains and points its frame pointer at an unmapped page.
Without this patch the guest panicked as above in 3 of 3 runs. With it,
the guest survived 3 of 3 runs of 60 seconds, and the host counted
148,441 to 153,334 kvm_async_pf_not_present events in the first 20
seconds of each. On 6.18.50 the results were the same: the guest
panicked without the patch and survived with it. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Fix page dirtying in sev_gmem_post_populate()
set_page_dirty() requires that the caller holds some kind of lock to
ensure that the page's mapping does not concurrently go away.
That is not the case for a random page we got from get_user_pages_fast(),
so use set_page_dirty_lock().
[sean: tag for stable] |
| 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 nested state
is freed with the MMU still pointing at the nested MMU, KVM will hit a NULL
pointer deref when attempting to get L1=>L2 EPTP.
BUG: kernel NULL pointer dereference, address: 0000000000000078
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 114a2d067 P4D 111743067 PUD 11141f067 PMD 0
Oops: Oops: 0000 [#1] SMP
CPU: 20 UID: 1000 PID: 1272 Comm: nested_tdp_faul Not tainted 7.3.0-rc4-8c89f11d1a99b-sink-vm #1914 PREEMPTLAZY
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:nested_ept_get_eptp+0xb/0x10 [kvm_intel]
Call Trace:
<TASK>
kvm_mmu_load+0xcd/0x870 [kvm]
kvm_arch_vcpu_ioctl_run+0x18f5/0x1f80 [kvm]
kvm_vcpu_ioctl+0x2c7/0x970 [kvm]
__x64_sys_ioctl+0x90/0xd0
do_syscall_64+0x9c/0x4d0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x47491b
</TASK>
Modules linked in: kvm_intel kvm irqbypass
CR2: 0000000000000078
---[ end trace 0000000000000000 ]---
RIP: 0010:nested_ept_get_eptp+0xb/0x10 [kvm_intel]
[sean: write changelog] |
| 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 longer protects the connector's object
from disappearing. An unprivileged fdinfo read racing the final detach
can consequently call igrab(NULL):
BUG: KASAN: null-ptr-deref in igrab+0x24/0x100
Write of size 4 at addr 0000000000000148
Call Trace:
igrab+0x24/0x100
inotify_show_fdinfo+0x1dc/0x5e0
seq_show+0x397/0x690
Set a DESTROYING flag under conn->lock before starting the walk, and
reject new marks on that connector with -ENOENT. The existing add-mark
error paths undo the temporary group-list entry and the backend's watch
allocation. Do not wait for teardown while holding the group mutex,
which the destroyer needs. Once the old connector is detached, an add
can install a fresh connector as before.
This closes the insertion race for all object types using the common
connector teardown, without changing the mark reference or SRCU lifetime
rules. |
| 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
dereferences a NULL s_fs_info, the freed sbi or the destroyed percpu
counters.
With a pathwalk held up in ext4_get_link() while the last reference
goes away:
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
RIP: 0010:ext4_getblk+0xf0/0x640
Call Trace:
<TASK>
ext4_get_link+0x26c/0x410
pick_link+0xf96/0x1780
step_into_slowpath+0x9b8/0x1250
path_lookupat+0x484/0xb00
filename_lookup+0x1f1/0x5b0
vfs_statx+0xd7/0x3b0
vfs_fstatat+0x4d/0x90
__do_sys_newfstatat+0xa0/0x100
do_syscall_64+0x10e/0x5e0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
So far that has been hard to hit. umount(2) waits for a grace period in
namespace_unlock() before it drops the mount, so only a mount whose last
reference goes away elsewhere, like the close of a file or a chdir out of
a lazily unmounted directory, can race a walker.
Keep sb->s_fs_info and free the sbi together with the extent status
counters after a grace period. Split the counters out of
ext4_es_unregister_shrinker() for that. The shrinker still gets wasted
in ext4_put_super(), the counters go with the sbi. |
| 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 gone.
With a pathwalk held up in tracefs_d_revalidate() while the dentry goes
away:
BUG: KASAN: slab-use-after-free in tracefs_d_revalidate+0x76/0x90
Read of size 1 at addr ff1100010152d8d0 by task walker/97
Call Trace:
<TASK>
tracefs_d_revalidate+0x76/0x90
lookup_fast+0x320/0x640
path_lookupat+0x160/0xb00
filename_lookup+0x1f1/0x5b0
vfs_statx+0xd7/0x3b0
vfs_fstatat+0x4d/0x90
__do_sys_newfstatat+0xa0/0x100
do_syscall_64+0x10e/0x5e0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[...]
Allocated by task 1:
__kmalloc_cache_noprof+0x249/0x560
eventfs_create_dir+0x7a/0x590
event_create_dir+0x2fb/0xcf0
trace_add_event_call+0xbf/0x150
[...]
Freed by task 11:
kfree+0x1db/0x5b0
srcu_invoke_callbacks+0x3a3/0x620
process_one_work+0x937/0x1810
worker_thread+0x4f1/0xd60
Before commit 8e556432477e ("eventfs: Use SRCU for freeing
eventfs_inodes") release_ei() used call_rcu(), which covered the walker,
while eventfs_iterate() needs the SRCU grace period. Wait for both and
chain call_rcu() from the SRCU callback. |
| 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_ns() and never dropped the
mount. Commit 7229d74e5e8c ("ipc: create_ipc_ns: drop mqueue mount on
sysctl setup failure") tried to fix that with a mntput() but that
doesn't help for a long-term mount.
Use kern_unmount(). free_ipc() open-codes the same thing for a namespace
that made it. |
| 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 walker/99
Call Trace:
<TASK>
ntfs_nls_to_utf16+0x752/0x940
ntfs_d_hash+0x22b/0x500
link_path_walk+0x11ad/0x1d30
path_lookupat+0x63/0xb00
filename_lookup+0x1f1/0x5b0
vfs_statx+0xd7/0x3b0
[...]
Allocated by task 95:
__kmalloc_cache_noprof+0x249/0x560
ntfs_init_fs_context+0x2db/0x5a0
alloc_fs_context+0x52e/0xc70
[...]
Freed by task 98:
kfree+0x1db/0x5b0
deactivate_locked_super+0x9c/0xf0
cleanup_mnt+0x9f/0x130
task_work_run+0x131/0x250
The bug is currently masked by the grace period in namespace_unlock()
for umount(2). Keep the necessary information until the filesystem
private info is freed and free it with an rcu delay.
ntfs3_free_sbi() now runs from an rcu callback and drops the upcase
table via ntfs_put_shared(). So switch s_shared_lock over to
spin_lock_bh(). Otherwise the callback can deadlock against a task
holding the lock on the same cpu. |
| 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(CLONE_NEWNS) and mount propagation make
such copies.
So a task that is root in its own user namespace gets rid of a locked
cover on a file without a race and without touching the filesystem
below it. It makes a child with a mount namespace of its own, binds the
child's /proc/<pid>/ns/mnt beneath the cover with MOVE_MOUNT_BENEATH,
which hands the lock to that bind, and calls unshare(CLONE_NEWNS). The
new mount namespace has nothing on the file. That's the usual way to
mask a single file, a bind of /dev/null or of an empty file. With a
bind of an ordinary file the file stays covered.
copy_tree() already refuses to leave out a locked unbindable mount with
-EPERM since commit df7342b24018 ("mount: Don't allow copying
MNT_UNBINDABLE|MNT_LOCKED mounts"). Do the same for a locked mount of a
mount namespace file. That also covers a tree copied with
CL_COPY_MNT_NS_FILE and attached into a mount namespace of another user
namespace where lock_mnt_tree() locks it. Note that unshare(CLONE_NEWNS)
and clone(CLONE_NEWNS) fail with EPERM from such a mount namespace from
then on. The mount can't be left out and it can't be unmounted.
And refuse to move a mount of a mount namespace file beneath a locked
mount in the first place. Otherwise the task ends up with a mount it
can't unmount and an unshare() that fails for good.
Chris also found a second mount that goes away by itself, a clone of an
automounted mount that shrink_submounts() took along with its parent.
Commit f78ddcc87224 ("namespace: never expire a locked mount") took
care of that one.
Chris's reproducer is appended. Mode nsfile reads SECRET after the
unshare() on 7.3-rc7, with this patch the move_mount() fails with
EINVAL and the file stays covered. nsfile-control uses an ordinary file
and reads MASK both ways.
// SPDX-License-Identifier: GPL-2.0
/*
* Get rid of a locked cover with MOVE_MOUNT_BENEATH.
*
* The "admin" (root) makes a tmpfs W:
* W/D file, holds SECRET, covered by a bind of a file with MASK
* W/Dd/inner file, holds SECRET, Dd is covered by a bind of a directory
* whose "inner" holds MASK
* W/own directory of uid 1000 with the file "mine" and the
* directory "minedir", whose "inner" holds MINE
* W/dbg debugfs, mode 755. dbg/tracing is an automount point
* The "attacker" is uid 1000. It enters a new user namespace with a new mount
* namespace, so W and both covers are locked there.
*
* usage: prog MODE
* plain put a bind of own/mine beneath the cover of D, unmount the cover
* nsfile put a bind of the mount namespace file of a child beneath the
* cover of D, then unshare(CLONE_NEWNS)
* nsfile-control the same with a bind of own/mine
* shrink put a bind of the automounted tracefs beneath the cover of Dd,
* unmount the cover, put a tmpfs beneath W, call umount(W), which fails
* shrink-control the same with a bind of own/minedir
* The environment variable AUTOMOUNT_DIR names another automount point for "shrink".
*/
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
---truncated--- |
| 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-threaded processes typically implicitly use FUT_OFF_MMSHARED by
setting clear_child_tid such that it points into anonymous memory, which
causes mm_release() in a multi-threaded mm to perform FUTEX_WAKE.) |
| 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 in that mapping.
Check the selected per-CPU register page before taking its reference and
return VM_FAULT_SIGBUS if it is absent. |
| 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. |
| 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 CONFIG_INIT_STACK_ALL_ZERO
the wild load becomes a NULL dereference at offset 0xa0
(&trans->cm_handle_connect) in the iw_cm_wq workqueue.
GCC masks the bug in default builds by folding the uninitialized
load into &rds_ib_transport; Clang-built kernels take the real
uninitialized path and oops.
The active side can land on a non-IB device too: the id that
rds_ib_conn_path_connect() creates is not restricted to a node type,
so rdma_resolve_addr() binds it to whichever device serves the local
address, and an iWARP RNIC on the same netdev qualifies. The crash
there is different: resolving a route on an iWARP id never fills in
cm_id->route.path_rec, and the ROUTE_RESOLVED case writes
path_rec[0].sl before it calls into the transport.
The iWARP transport was dropped long ago and IB is the only
transport left, so make that explicit: initialize trans to
&rds_ib_transport at declaration, drop the conditional assignment,
reject a connect request that arrives on a non-IB device, and drop a
connection whose address resolved to one instead of resolving a
route on it. The rejection is limited to RDMA_CM_EVENT_CONNECT_REQUEST
on purpose: a non-zero return from the handler makes rdma_cm destroy
the id the event was delivered on, which is right for the request's
freshly created id but would free a connection id that RDS still owns
for any other event. On the active side the id stays ic->i_cm_id and
the connection's shutdown destroys it, so that case returns 0.
[achender: reject only on RDMA_CM_EVENT_CONNECT_REQUEST instead of
bailing out for every event on a non-IB device, so that rdma_cm does
not destroy connection ids RDS still tracks; drop a connection whose
address resolved to a non-IB device before a route is resolved on it;
changelog adjusted] |
| 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 panic the host.
KASAN: null-ptr-deref in range [0x38-0x3f]
RIP: sctp_outq_tail+0x49e/0xaa0
Call Trace:
sctp_primitive_SEND
sctp_sendmsg_to_asoc
sctp_sendmsg
A range check alone is insufficient. Stream reconfiguration can grow the
output count again while the lock is released without recreating extensions
freed by the earlier shrink. The stream can then be in range while its
extension remains NULL. The send-buffer wait has the same issue.
Factor the range and extension checks into a helper and repeat both after
each send-path wait that drops the socket lock. Once the lock is
reacquired, the validation remains stable through data creation and
queueing.
If validation fails after the connect wait, the auto-created association is
already established. Return ESRCH so the existing caller path keeps it
under state-machine ownership instead of freeing it directly, which would
leave protocol, counter and socket state inconsistent. |
| 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 refcount_t warnings
triggered from rpmsg_recv_done() in virtio_rpmsg_bus:
refcount_t: addition on 0; use-after-free.
refcount_t: underflow; use-after-free.
refcount_t: saturated; leaking memory.
Leading finally to an "Unable to handle kernel paging request" oops.
Reproducing this problem took between 30 minutes and roughly 30 hours
under the same workload.
Hardware watchpoints on the refcount of a struct rpmsg_endpoint showed
it was overwritten from 2 to 1 by __pi_memcpy_generic() in the
irq/155-spi2.0 thread. Additionally it was found that a "normal"
rpmsg_recv_done() took 11µs +/-2µs from its kref_get to kref_put. In
the error case the same sequence took about 215µs +/-10µs. Based on
this, an LLM was used to identify the size mismatch fixed here.
Allocate the buffers with DMA_CACHE_ALIGNED_LEN(dma_len) so they cover
the full mapped length, and use the same length for
dma_sync_single_for_cpu() to stay consistent with map and unmap.
With this patch applied, the same workload ran for more than 200 hours
without the problem reproducing. |
| 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 dereferenced as a kernel stacktrace pointer in
get_field_size() and trace_stack().
Furthermore, checking strstr(hist_field->type, "long[") is insufficient
because tracepoint fields defined with __bitmask() or __rel_bitmask()
also have type "__data_loc unsigned long[]" or "__rel_loc unsigned
long[]", whilst create_hist_field() treats them as 4-byte scalar values
without HIST_FIELD_FL_STACKTRACE.
Propagate HIST_FIELD_FL_STACKTRACE to variable references and field
variables (whilst excluding variable aliases from per-element
stacktrace capture), and reject any mismatch between
HIST_FIELD_FL_STACKTRACE and field->is_stack in check_synth_field(). |
| 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. |
| 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. |
