| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix potential UAF in nfsd4_cb_getattr_release
Once we drop the delegation reference, the fields embedded in it are no
longer safe to access. Do that last. |
| In the Linux kernel, the following vulnerability has been resolved:
netem: fix return value if duplicate enqueue fails
There is a bug in netem_enqueue() introduced by
commit 5845f706388a ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
that can lead to a use-after-free.
This commit made netem_enqueue() always return NET_XMIT_SUCCESS
when a packet is duplicated, which can cause the parent qdisc's q.qlen
to be mistakenly incremented. When this happens qlen_notify() may be
skipped on the parent during destruction, leaving a dangling pointer
for some classful qdiscs like DRR.
There are two ways for the bug happen:
- If the duplicated packet is dropped by rootq->enqueue() and then
the original packet is also dropped.
- If rootq->enqueue() sends the duplicated packet to a different qdisc
and the original packet is dropped.
In both cases NET_XMIT_SUCCESS is returned even though no packets
are enqueued at the netem qdisc.
The fix is to defer the enqueue of the duplicate packet until after
the original packet has been guaranteed to return NET_XMIT_SUCCESS. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: move stopping keep-alive into nvme_uninit_ctrl()
Commit 4733b65d82bd ("nvme: start keep-alive after admin queue setup")
moves starting keep-alive from nvme_start_ctrl() into
nvme_init_ctrl_finish(), but don't move stopping keep-alive into
nvme_uninit_ctrl(), so keep-alive work can be started and keep pending
after failing to start controller, finally use-after-free is triggered if
nvme host driver is unloaded.
This patch fixes kernel panic when running nvme/004 in case that connection
failure is triggered, by moving stopping keep-alive into nvme_uninit_ctrl().
This way is reasonable because keep-alive is now started in
nvme_init_ctrl_finish(). |
| In the Linux kernel, the following vulnerability has been resolved:
atm: idt77252: prevent use after free in dequeue_rx()
We can't dereference "skb" after calling vcc->push() because the skb
is released. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix possible UAF in ip6_finish_output2()
If skb_expand_head() returns NULL, skb has been freed
and associated dst/idev could also have been freed.
We need to hold rcu_read_lock() to make sure the dst and
associated idev are alive. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent possible UAF in ip6_xmit()
If skb_expand_head() returns NULL, skb has been freed
and the associated dst/idev could also have been freed.
We must use rcu_read_lock() to prevent a possible UAF. |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: Serialise kcm_sendmsg() for the same socket.
syzkaller reported UAF in kcm_release(). [0]
The scenario is
1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.
2. Thread A resumes building skb from kcm->seq_skb but is blocked
by sk_stream_wait_memory()
3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb
and puts the skb to the write queue
4. Thread A faces an error and finally frees skb that is already in the
write queue
5. kcm_release() does double-free the skb in the write queue
When a thread is building a MSG_MORE skb, another thread must not touch it.
Let's add a per-sk mutex and serialise kcm_sendmsg().
[0]:
BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline]
BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline]
BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167
CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x178/0x518 mm/kasan/report.c:488
kasan_report+0xd8/0x138 mm/kasan/report.c:601
__asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
__skb_unlink include/linux/skbuff.h:2366 [inline]
__skb_dequeue include/linux/skbuff.h:2385 [inline]
__skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
__skb_queue_purge include/linux/skbuff.h:3181 [inline]
kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
__sock_release net/socket.c:659 [inline]
sock_close+0xa4/0x1e8 net/socket.c:1421
__fput+0x30c/0x738 fs/file_table.c:376
____fput+0x20/0x30 fs/file_table.c:404
task_work_run+0x230/0x2e0 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x618/0x1f64 kernel/exit.c:871
do_group_exit+0x194/0x22c kernel/exit.c:1020
get_signal+0x1500/0x15ec kernel/signal.c:2893
do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249
do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148
exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Allocated by task 6166:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626
unpoison_slab_object mm/kasan/common.c:314 [inline]
__kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903
__alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641
alloc_skb include/linux/skbuff.h:1296 [inline]
kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
sock_sendmsg+0x220/0x2c0 net/socket.c:768
splice_to_socket+0x7cc/0xd58 fs/splice.c:889
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0xec/0x1d8 fs/splice.c:1164
splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108
do_splice_direct_actor
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Have format file honor EVENT_FILE_FL_FREED
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).
All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.
A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them. The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.
This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:
In one console run:
# cd tools/testing/selftests/user_events
# while true; do ./ftrace_test; done
And in another console run:
# cd /sys/kernel/tracing/
# while true; do cat events/user_events/__test_event/format; done 2>/dev/null
With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.
After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: vhci-hcd: Do not drop references before new references are gained
At a few places the driver carries stale pointers
to references that can still be used. Make sure that does not happen.
This strictly speaking closes ZDI-CAN-22273, though there may be
similar races in the driver. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix CT entry update leaks of modify header context
The cited commit allocates a new modify header to replace the old
one when updating CT entry. But if failed to allocate a new one, eg.
exceed the max number firmware can support, modify header will be
an error pointer that will trigger a panic when deallocating it. And
the old modify header point is copied to old attr. When the old
attr is freed, the old modify header is lost.
Fix it by restoring the old attr to attr when failed to allocate a
new modify header context. So when the CT entry is freed, the right
modify header context will be freed. And the panic of accessing
error pointer is also fixed. |
| In the Linux kernel, the following vulnerability has been resolved:
cgroup/cpuset: Prevent UAF in proc_cpuset_show()
An UAF can happen when /proc/cpuset is read as reported in [1].
This can be reproduced by the following methods:
1.add an mdelay(1000) before acquiring the cgroup_lock In the
cgroup_path_ns function.
2.$cat /proc/<pid>/cpuset repeatly.
3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/
$umount /sys/fs/cgroup/cpuset/ repeatly.
The race that cause this bug can be shown as below:
(umount) | (cat /proc/<pid>/cpuset)
css_release | proc_cpuset_show
css_release_work_fn | css = task_get_css(tsk, cpuset_cgrp_id);
css_free_rwork_fn | cgroup_path_ns(css->cgroup, ...);
cgroup_destroy_root | mutex_lock(&cgroup_mutex);
rebind_subsystems |
cgroup_free_root |
| // cgrp was freed, UAF
| cgroup_path_ns_locked(cgrp,..);
When the cpuset is initialized, the root node top_cpuset.css.cgrp
will point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will
allocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated
&cgroup_root.cgrp. When the umount operation is executed,
top_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp.
The problem is that when rebinding to cgrp_dfl_root, there are cases
where the cgroup_root allocated by setting up the root for cgroup v1
is cached. This could lead to a Use-After-Free (UAF) if it is
subsequently freed. The descendant cgroups of cgroup v1 can only be
freed after the css is released. However, the css of the root will never
be released, yet the cgroup_root should be freed when it is unmounted.
This means that obtaining a reference to the css of the root does
not guarantee that css.cgrp->root will not be freed.
Fix this problem by using rcu_read_lock in proc_cpuset_show().
As cgroup_root is kfree_rcu after commit d23b5c577715
("cgroup: Make operations on the cgroup root_list RCU safe"),
css->cgroup won't be freed during the critical section.
To call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to
replace task_get_css with task_css.
[1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/iwcm: Fix a use-after-free related to destroying CM IDs
iw_conn_req_handler() associates a new struct rdma_id_private (conn_id) with
an existing struct iw_cm_id (cm_id) as follows:
conn_id->cm_id.iw = cm_id;
cm_id->context = conn_id;
cm_id->cm_handler = cma_iw_handler;
rdma_destroy_id() frees both the cm_id and the struct rdma_id_private. Make
sure that cm_work_handler() does not trigger a use-after-free by only
freeing of the struct rdma_id_private after all pending work has finished. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: fix crashes from deferred split racing folio migration
Even on 6.10-rc6, I've been seeing elusive "Bad page state"s (often on
flags when freeing, yet the flags shown are not bad: PG_locked had been
set and cleared??), and VM_BUG_ON_PAGE(page_ref_count(page) == 0)s from
deferred_split_scan()'s folio_put(), and a variety of other BUG and WARN
symptoms implying double free by deferred split and large folio migration.
6.7 commit 9bcef5973e31 ("mm: memcg: fix split queue list crash when large
folio migration") was right to fix the memcg-dependent locking broken in
85ce2c517ade ("memcontrol: only transfer the memcg data for migration"),
but missed a subtlety of deferred_split_scan(): it moves folios to its own
local list to work on them without split_queue_lock, during which time
folio->_deferred_list is not empty, but even the "right" lock does nothing
to secure the folio and the list it is on.
Fortunately, deferred_split_scan() is careful to use folio_try_get(): so
folio_migrate_mapping() can avoid the race by folio_undo_large_rmappable()
while the old folio's reference count is temporarily frozen to 0 - adding
such a freeze in the !mapping case too (originally, folio lock and
unmapping and no swap cache left an anon folio unreachable, so no freezing
was needed there: but the deferred split queue offers a way to reach it). |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: fix race between delayed_work() and ceph_monc_stop()
The way the delayed work is handled in ceph_monc_stop() is prone to
races with mon_fault() and possibly also finish_hunting(). Both of
these can requeue the delayed work which wouldn't be canceled by any of
the following code in case that happens after cancel_delayed_work_sync()
runs -- __close_session() doesn't mess with the delayed work in order
to avoid interfering with the hunting interval logic. This part was
missed in commit b5d91704f53e ("libceph: behave in mon_fault() if
cur_mon < 0") and use-after-free can still ensue on monc and objects
that hang off of it, with monc->auth and monc->monmap being
particularly susceptible to quickly being reused.
To fix this:
- clear monc->cur_mon and monc->hunting as part of closing the session
in ceph_monc_stop()
- bail from delayed_work() if monc->cur_mon is cleared, similar to how
it's done in mon_fault() and finish_hunting() (based on monc->hunting)
- call cancel_delayed_work_sync() after the session is closed |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix double free err_addr pointer warnings
In amdgpu_umc_bad_page_polling_timeout, the amdgpu_umc_handle_bad_pages
will be run many times so that double free err_addr in some special case.
So set the err_addr to NULL to avoid the warnings. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: unconditionally flush pending work before notifier
syzbot reports:
KASAN: slab-uaf in nft_ctx_update include/net/netfilter/nf_tables.h:1831
KASAN: slab-uaf in nft_commit_release net/netfilter/nf_tables_api.c:9530
KASAN: slab-uaf int nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597
Read of size 2 at addr ffff88802b0051c4 by task kworker/1:1/45
[..]
Workqueue: events nf_tables_trans_destroy_work
Call Trace:
nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline]
nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline]
nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597
Problem is that the notifier does a conditional flush, but its possible
that the table-to-be-removed is still referenced by transactions being
processed by the worker, so we need to flush unconditionally.
We could make the flush_work depend on whether we found a table to delete
in nf-next to avoid the flush for most cases.
AFAICS this problem is only exposed in nf-next, with
commit e169285f8c56 ("netfilter: nf_tables: do not store nft_ctx in transaction objects"),
with this commit applied there is an unconditional fetch of
table->family which is whats triggering the above splat. |
| In the Linux kernel, the following vulnerability has been resolved:
net: rswitch: Avoid use-after-free in rswitch_poll()
The use-after-free is actually in rswitch_tx_free(), which is inlined in
rswitch_poll(). Since `skb` and `gq->skbs[gq->dirty]` are in fact the
same pointer, the skb is first freed using dev_kfree_skb_any(), then the
value in skb->len is used to update the interface statistics.
Let's move around the instructions to use skb->len before the skb is
freed.
This bug is trivial to reproduce using KFENCE. It will trigger a splat
every few packets. A simple ARP request or ICMP echo request is enough. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix remap of arena.
The bpf arena logic didn't account for mremap operation. Add a refcnt for
multiple mmap events to prevent use-after-free in arena_vm_close. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mana: Fix possible double free in error handling path
When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), callback function adev_release
calls kfree(madev). We shouldn't call kfree(madev) again
in the error handling path. Set 'madev' to NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: avoid double free special payload
If a discard request needs to be retried, and that retry may fail before
a new special payload is added, a double free will result. Clear the
RQF_SPECIAL_LOAD when the request is cleaned. |
