| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Use scratch field in MMIO fragment to hold small write values
When exiting to userspace to service an emulated MMIO write, copy the
to-be-written value to a scratch field in the MMIO fragment if the size
of the data payload is 8 bytes or less, i.e. can fit in a single chunk,
instead of pointing the fragment directly at the source value.
This fixes a class of use-after-free bugs that occur when the emulator
initiates a write using an on-stack, local variable as the source, the
write splits a page boundary, *and* both pages are MMIO pages. Because
KVM's ABI only allows for physically contiguous MMIO requests, accesses
that split MMIO pages are separated into two fragments, and are sent to
userspace one at a time. When KVM attempts to complete userspace MMIO in
response to KVM_RUN after the first fragment, KVM will detect the second
fragment and generate a second userspace exit, and reference the on-stack
variable.
The issue is most visible if the second KVM_RUN is performed by a separate
task, in which case the stack of the initiating task can show up as truly
freed data.
==================================================================
BUG: KASAN: use-after-free in complete_emulated_mmio+0x305/0x420
Read of size 1 at addr ffff888009c378d1 by task syz-executor417/984
CPU: 1 PID: 984 Comm: syz-executor417 Not tainted 5.10.0-182.0.0.95.h2627.eulerosv2r13.x86_64 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace:
dump_stack+0xbe/0xfd
print_address_description.constprop.0+0x19/0x170
__kasan_report.cold+0x6c/0x84
kasan_report+0x3a/0x50
check_memory_region+0xfd/0x1f0
memcpy+0x20/0x60
complete_emulated_mmio+0x305/0x420
kvm_arch_vcpu_ioctl_run+0x63f/0x6d0
kvm_vcpu_ioctl+0x413/0xb20
__se_sys_ioctl+0x111/0x160
do_syscall_64+0x30/0x40
entry_SYSCALL_64_after_hwframe+0x67/0xd1
RIP: 0033:0x42477d
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faa8e6890e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004d7338 RCX: 000000000042477d
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00000000004d7330 R08: 00007fff28d546df R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004d733c
R13: 0000000000000000 R14: 000000000040a200 R15: 00007fff28d54720
The buggy address belongs to the page:
page:0000000029f6a428 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9c37
flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000000 0000000000000000 ffffea0000270dc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888009c37780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888009c37800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888009c37880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888009c37900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888009c37980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
The bug can also be reproduced with a targeted KVM-Unit-Test by hacking
KVM to fill a large on-stack variable in complete_emulated_mmio(), i.e. by
overwrite the data value with garbage.
Limit the use of the scratch fields to 8-byte or smaller accesses, and to
just writes, as larger accesses and reads are not affected thanks to
implementation details in the emulator, but add a sanity check to ensure
those details don't change in the future. Specifically, KVM never uses
on-stack variables for accesses larger that 8 bytes, e.g. uses an operand
in the emulator context, and *al
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: qcom: q6apm: move component registration to unmanaged version
q6apm component registers dais dynamically from ASoC toplology, which
are allocated using device managed version apis. Allocating both
component and dynamic dais using managed version could lead to incorrect
free ordering, dai will be freed while component still holding references
to it.
Fix this issue by moving component to unmanged version so
that the dai pointers are only freeded after the component is removed.
==================================================================
BUG: KASAN: slab-use-after-free in snd_soc_del_component_unlocked+0x3d4/0x400 [snd_soc_core]
Read of size 8 at addr ffff00084493a6e8 by task kworker/u48:0/3426
Tainted: [W]=WARN
Hardware name: LENOVO 21N2ZC5PUS/21N2ZC5PUS, BIOS N42ET57W (1.31 ) 08/08/2024
Workqueue: pdr_notifier_wq pdr_notifier_work [pdr_interface]
Call trace:
show_stack+0x28/0x7c (C)
dump_stack_lvl+0x60/0x80
print_report+0x160/0x4b4
kasan_report+0xac/0xfc
__asan_report_load8_noabort+0x20/0x34
snd_soc_del_component_unlocked+0x3d4/0x400 [snd_soc_core]
snd_soc_unregister_component_by_driver+0x50/0x88 [snd_soc_core]
devm_component_release+0x30/0x5c [snd_soc_core]
devres_release_all+0x13c/0x210
device_unbind_cleanup+0x20/0x190
device_release_driver_internal+0x350/0x468
device_release_driver+0x18/0x30
bus_remove_device+0x1a0/0x35c
device_del+0x314/0x7f0
device_unregister+0x20/0xbc
apr_remove_device+0x5c/0x7c [apr]
device_for_each_child+0xd8/0x160
apr_pd_status+0x7c/0xa8 [apr]
pdr_notifier_work+0x114/0x240 [pdr_interface]
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20
Allocated by task 77:
kasan_save_stack+0x40/0x68
kasan_save_track+0x20/0x40
kasan_save_alloc_info+0x44/0x58
__kasan_kmalloc+0xbc/0xdc
__kmalloc_node_track_caller_noprof+0x1f4/0x620
devm_kmalloc+0x7c/0x1c8
snd_soc_register_dai+0x50/0x4f0 [snd_soc_core]
soc_tplg_pcm_elems_load+0x55c/0x1eb8 [snd_soc_core]
snd_soc_tplg_component_load+0x4f8/0xb60 [snd_soc_core]
audioreach_tplg_init+0x124/0x1fc [snd_q6apm]
q6apm_audio_probe+0x10/0x1c [snd_q6apm]
snd_soc_component_probe+0x5c/0x118 [snd_soc_core]
soc_probe_component+0x44c/0xaf0 [snd_soc_core]
snd_soc_bind_card+0xad0/0x2370 [snd_soc_core]
snd_soc_register_card+0x3b0/0x4c0 [snd_soc_core]
devm_snd_soc_register_card+0x50/0xc8 [snd_soc_core]
x1e80100_platform_probe+0x208/0x368 [snd_soc_x1e80100]
platform_probe+0xc0/0x188
really_probe+0x188/0x804
__driver_probe_device+0x158/0x358
driver_probe_device+0x60/0x190
__device_attach_driver+0x16c/0x2a8
bus_for_each_drv+0x100/0x194
__device_attach+0x174/0x380
device_initial_probe+0x14/0x20
bus_probe_device+0x124/0x154
deferred_probe_work_func+0x140/0x220
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20
Freed by task 3426:
kasan_save_stack+0x40/0x68
kasan_save_track+0x20/0x40
__kasan_save_free_info+0x4c/0x80
__kasan_slab_free+0x78/0xa0
kfree+0x100/0x4a4
devres_release_all+0x144/0x210
device_unbind_cleanup+0x20/0x190
device_release_driver_internal+0x350/0x468
device_release_driver+0x18/0x30
bus_remove_device+0x1a0/0x35c
device_del+0x314/0x7f0
device_unregister+0x20/0xbc
apr_remove_device+0x5c/0x7c [apr]
device_for_each_child+0xd8/0x160
apr_pd_status+0x7c/0xa8 [apr]
pdr_notifier_work+0x114/0x240 [pdr_interface]
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20 |
| In the Linux kernel, the following vulnerability has been resolved:
mm: blk-cgroup: fix use-after-free in cgwb_release_workfn()
cgwb_release_workfn() calls css_put(wb->blkcg_css) and then later accesses
wb->blkcg_css again via blkcg_unpin_online(). If css_put() drops the last
reference, the blkcg can be freed asynchronously (css_free_rwork_fn ->
blkcg_css_free -> kfree) before blkcg_unpin_online() dereferences the
pointer to access blkcg->online_pin, resulting in a use-after-free:
BUG: KASAN: slab-use-after-free in blkcg_unpin_online (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 block/blk-cgroup.c:1367)
Write of size 4 at addr ff11000117aa6160 by task kworker/71:1/531
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
blkcg_unpin_online (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 block/blk-cgroup.c:1367)
cgwb_release_workfn (mm/backing-dev.c:629)
process_scheduled_works (kernel/workqueue.c:3278 kernel/workqueue.c:3385)
Freed by task 1016:
kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6246 mm/slub.c:6561)
css_free_rwork_fn (kernel/cgroup/cgroup.c:5542)
process_scheduled_works (kernel/workqueue.c:3302 kernel/workqueue.c:3385)
** Stack based on commit 66672af7a095 ("Add linux-next specific files
for 20260410")
I am seeing this crash sporadically in Meta fleet across multiple kernel
versions. A full reproducer is available at:
https://github.com/leitao/debug/blob/main/reproducers/repro_blkcg_uaf.sh
(The race window is narrow. To make it easily reproducible, inject a
msleep(100) between css_put() and blkcg_unpin_online() in
cgwb_release_workfn(). With that delay and a KASAN-enabled kernel, the
reproducer triggers the splat reliably in less than a second.)
Fix this by moving blkcg_unpin_online() before css_put(), so the
cgwb's CSS reference keeps the blkcg alive while blkcg_unpin_online()
accesses it. |
| In the Linux kernel, the following vulnerability has been resolved:
media: em28xx: fix use-after-free in em28xx_v4l2_open()
em28xx_v4l2_open() reads dev->v4l2 without holding dev->lock,
creating a race with em28xx_v4l2_init()'s error path and
em28xx_v4l2_fini(), both of which free the em28xx_v4l2 struct
and set dev->v4l2 to NULL under dev->lock.
This race leads to two issues:
- use-after-free in v4l2_fh_init() when accessing vdev->ctrl_handler,
since the video_device is embedded in the freed em28xx_v4l2 struct.
- NULL pointer dereference in em28xx_resolution_set() when accessing
v4l2->norm, since dev->v4l2 has been set to NULL.
Fix this by moving the mutex_lock() before the dev->v4l2 read and
adding a NULL check for dev->v4l2 under the lock. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: 6fire: fix use-after-free on disconnect
In usb6fire_chip_abort(), the chip struct is allocated as the card's
private data (via snd_card_new with sizeof(struct sfire_chip)). When
snd_card_free_when_closed() is called and no file handles are open, the
card and embedded chip are freed synchronously. The subsequent
chip->card = NULL write then hits freed slab memory.
Call trace:
usb6fire_chip_abort sound/usb/6fire/chip.c:59 [inline]
usb6fire_chip_disconnect+0x348/0x358 sound/usb/6fire/chip.c:182
usb_unbind_interface+0x1a8/0x88c drivers/usb/core/driver.c:458
...
hub_event+0x1a04/0x4518 drivers/usb/core/hub.c:5953
Fix by moving the card lifecycle out of usb6fire_chip_abort() and into
usb6fire_chip_disconnect(). The card pointer is saved in a local
before any teardown, snd_card_disconnect() is called first to prevent
new opens, URBs are aborted while chip is still valid, and
snd_card_free_when_closed() is called last so chip is never accessed
after the card may be freed. |
| In the Linux kernel, the following vulnerability has been resolved:
bcache: fix cached_dev.sb_bio use-after-free and crash
In our production environment, we have received multiple crash reports
regarding libceph, which have caught our attention:
```
[6888366.280350] Call Trace:
[6888366.280452] blk_update_request+0x14e/0x370
[6888366.280561] blk_mq_end_request+0x1a/0x130
[6888366.280671] rbd_img_handle_request+0x1a0/0x1b0 [rbd]
[6888366.280792] rbd_obj_handle_request+0x32/0x40 [rbd]
[6888366.280903] __complete_request+0x22/0x70 [libceph]
[6888366.281032] osd_dispatch+0x15e/0xb40 [libceph]
[6888366.281164] ? inet_recvmsg+0x5b/0xd0
[6888366.281272] ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph]
[6888366.281405] ceph_con_process_message+0x79/0x140 [libceph]
[6888366.281534] ceph_con_v1_try_read+0x5d7/0xf30 [libceph]
[6888366.281661] ceph_con_workfn+0x329/0x680 [libceph]
```
After analyzing the coredump file, we found that the address of
dc->sb_bio has been freed. We know that cached_dev is only freed when it
is stopped.
Since sb_bio is a part of struct cached_dev, rather than an alloc every
time. If the device is stopped while writing to the superblock, the
released address will be accessed at endio.
This patch hopes to wait for sb_write to complete in cached_dev_free.
It should be noted that we analyzed the cause of the problem, then tell
all details to the QWEN and adopted the modifications it made. |
| In the Linux kernel, the following vulnerability has been resolved:
media: as102: fix to not free memory after the device is registered in as102_usb_probe()
In as102_usb driver, the following race condition occurs:
```
CPU0 CPU1
as102_usb_probe()
kzalloc(); // alloc as102_dev_t
....
usb_register_dev();
fd = sys_open("/path/to/dev"); // open as102 fd
....
usb_deregister_dev();
....
kfree(); // free as102_dev_t
....
sys_close(fd);
as102_release() // UAF!!
as102_usb_release()
kfree(); // DFB!!
```
When a USB character device registered with usb_register_dev() is later
unregistered (via usb_deregister_dev() or disconnect), the device node is
removed so new open() calls fail. However, file descriptors that are
already open do not go away immediately: they remain valid until the last
reference is dropped and the driver's .release() is invoked.
In as102, as102_usb_probe() calls usb_register_dev() and then, on an
error path, does usb_deregister_dev() and frees as102_dev_t right away.
If userspace raced a successful open() before the deregistration, that
open FD will later hit as102_release() --> as102_usb_release() and access
or free as102_dev_t again, occur a race to use-after-free and
double-free vuln.
The fix is to never kfree(as102_dev_t) directly once usb_register_dev()
has succeeded. After deregistration, defer freeing memory to .release().
In other words, let release() perform the last kfree when the final open
FD is closed. |
| In the Linux kernel, the following vulnerability has been resolved:
media: hackrf: fix to not free memory after the device is registered in hackrf_probe()
In hackrf driver, the following race condition occurs:
```
CPU0 CPU1
hackrf_probe()
kzalloc(); // alloc hackrf_dev
....
v4l2_device_register();
....
fd = sys_open("/path/to/dev"); // open hackrf fd
....
v4l2_device_unregister();
....
kfree(); // free hackrf_dev
....
sys_ioctl(fd, ...);
v4l2_ioctl();
video_is_registered() // UAF!!
....
sys_close(fd);
v4l2_release() // UAF!!
hackrf_video_release()
kfree(); // DFB!!
```
When a V4L2 or video device is unregistered, the device node is removed so
new open() calls are blocked.
However, file descriptors that are already open-and any in-flight I/O-do
not terminate immediately; they remain valid until the last reference is
dropped and the driver's release() is invoked.
Therefore, freeing device memory on the error path after hackrf_probe()
has registered dev it will lead to a race to use-after-free vuln, since
those already-open handles haven't been released yet.
And since release() free memory too, race to use-after-free and
double-free vuln occur.
To prevent this, if device is registered from probe(), it should be
modified to free memory only through release() rather than calling
kfree() directly. |
| In the Linux kernel, the following vulnerability has been resolved:
can: raw: fix ro->uniq use-after-free in raw_rcv()
raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.
Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.
[mkl: applied manually] |
| In the Linux kernel, the following vulnerability has been resolved:
driver core: platform: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.
Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.
Note that calling match() from __driver_attach() without the device lock
held is intentional. [1] |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btintel: serialize btintel_hw_error() with hci_req_sync_lock
btintel_hw_error() issues two __hci_cmd_sync() calls (HCI_OP_RESET
and Intel exception-info retrieval) without holding
hci_req_sync_lock(). This lets it race against
hci_dev_do_close() -> btintel_shutdown_combined(), which also runs
__hci_cmd_sync() under the same lock. When both paths manipulate
hdev->req_status/req_rsp concurrently, the close path may free the
response skb first, and the still-running hw_error path hits a
slab-use-after-free in kfree_skb().
Wrap the whole recovery sequence in hci_req_sync_lock/unlock so it
is serialized with every other synchronous HCI command issuer.
Below is the data race report and the kasan report:
BUG: data-race in __hci_cmd_sync_sk / btintel_shutdown_combined
read of hdev->req_rsp at net/bluetooth/hci_sync.c:199
by task kworker/u17:1/83:
__hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200
__hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223
btintel_hw_error+0x114/0x670 drivers/bluetooth/btintel.c:254
hci_error_reset+0x348/0xa30 net/bluetooth/hci_core.c:1030
write/free by task ioctl/22580:
btintel_shutdown_combined+0xd0/0x360
drivers/bluetooth/btintel.c:3648
hci_dev_close_sync+0x9ae/0x2c10 net/bluetooth/hci_sync.c:5246
hci_dev_do_close+0x232/0x460 net/bluetooth/hci_core.c:526
BUG: KASAN: slab-use-after-free in
sk_skb_reason_drop+0x43/0x380 net/core/skbuff.c:1202
Read of size 4 at addr ffff888144a738dc
by task kworker/u17:1/83:
__hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200
__hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223
btintel_hw_error+0x186/0x670 drivers/bluetooth/btintel.c:260 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Do not skip unrelated mode changes in DSC validation
Starting with commit 17ce8a6907f7 ("drm/amd/display: Add dsc pre-validation in
atomic check"), amdgpu resets the CRTC state mode_changed flag to false when
recomputing the DSC configuration results in no timing change for a particular
stream.
However, this is incorrect in scenarios where a change in MST/DSC configuration
happens in the same KMS commit as another (unrelated) mode change. For example,
the integrated panel of a laptop may be configured differently (e.g., HDR
enabled/disabled) depending on whether external screens are attached. In this
case, plugging in external DP-MST screens may result in the mode_changed flag
being dropped incorrectly for the integrated panel if its DSC configuration
did not change during precomputation in pre_validate_dsc().
At this point, however, dm_update_crtc_state() has already created new streams
for CRTCs with DSC-independent mode changes. In turn,
amdgpu_dm_commit_streams() will never release the old stream, resulting in a
memory leak. amdgpu_dm_atomic_commit_tail() will never acquire a reference to
the new stream either, which manifests as a use-after-free when the stream gets
disabled later on:
BUG: KASAN: use-after-free in dc_stream_release+0x25/0x90 [amdgpu]
Write of size 4 at addr ffff88813d836524 by task kworker/9:9/29977
Workqueue: events drm_mode_rmfb_work_fn
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0xa0
print_address_description.constprop.0+0x88/0x320
? dc_stream_release+0x25/0x90 [amdgpu]
print_report+0xfc/0x1ff
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x225/0x4e0
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_report+0xe1/0x180
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_check_range+0x125/0x200
dc_stream_release+0x25/0x90 [amdgpu]
dc_state_destruct+0x14d/0x5c0 [amdgpu]
dc_state_release.part.0+0x4e/0x130 [amdgpu]
dm_atomic_destroy_state+0x3f/0x70 [amdgpu]
drm_atomic_state_default_clear+0x8ee/0xf30
? drm_mode_object_put.part.0+0xb1/0x130
__drm_atomic_state_free+0x15c/0x2d0
atomic_remove_fb+0x67e/0x980
Since there is no reliable way of figuring out whether a CRTC has unrelated
mode changes pending at the time of DSC validation, remember the value of the
mode_changed flag from before the point where a CRTC was marked as potentially
affected by a change in DSC configuration. Reset the mode_changed flag to this
earlier value instead in pre_validate_dsc().
(cherry picked from commit cc7c7121ae082b7b82891baa7280f1ff2608f22b) |
| In the Linux kernel, the following vulnerability has been resolved:
net: add proper RCU protection to /proc/net/ptype
Yin Fengwei reported an RCU stall in ptype_seq_show() and provided
a patch.
Real issue is that ptype_seq_next() and ptype_seq_show() violate
RCU rules.
ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev
to get device name without any barrier.
At the same time, concurrent writers can remove a packet_type structure
(which is correctly freed after an RCU grace period) and clear pt->dev
without an RCU grace period.
Define ptype_iter_state to carry a dev pointer along seq_net_private:
struct ptype_iter_state {
struct seq_net_private p;
struct net_device *dev; // added in this patch
};
We need to record the device pointer in ptype_get_idx() and
ptype_seq_next() so that ptype_seq_show() is safe against
concurrent pt->dev changes.
We also need to add full RCU protection in ptype_seq_next().
(Missing READ_ONCE() when reading list.next values)
Many thanks to Dong Chenchen for providing a repro. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic
The decompress_io_ctx may be released asynchronously after
I/O completion. If this file is deleted immediately after read,
and the kworker of processing post_read_wq has not been executed yet
due to high workloads, It is possible that the inode(f2fs_inode_info)
is evicted and freed before it is used f2fs_free_dic.
The UAF case as below:
Thread A Thread B
- f2fs_decompress_end_io
- f2fs_put_dic
- queue_work
add free_dic work to post_read_wq
- do_unlink
- iput
- evict
- call_rcu
This file is deleted after read.
Thread C kworker to process post_read_wq
- rcu_do_batch
- f2fs_free_inode
- kmem_cache_free
inode is freed by rcu
- process_scheduled_works
- f2fs_late_free_dic
- f2fs_free_dic
- f2fs_release_decomp_mem
read (dic->inode)->i_compress_algorithm
This patch store compress_algorithm and sbi in dic to avoid inode UAF.
In addition, the previous solution is deprecated in [1] may cause system hang.
[1] https://lore.kernel.org/all/c36ab955-c8db-4a8b-a9d0-f07b5f426c3f@kernel.org |
| In the Linux kernel, the following vulnerability has been resolved:
padata: Fix pd UAF once and for all
There is a race condition/UAF in padata_reorder that goes back
to the initial commit. A reference count is taken at the start
of the process in padata_do_parallel, and released at the end in
padata_serial_worker.
This reference count is (and only is) required for padata_replace
to function correctly. If padata_replace is never called then
there is no issue.
In the function padata_reorder which serves as the core of padata,
as soon as padata is added to queue->serial.list, and the associated
spin lock released, that padata may be processed and the reference
count on pd would go away.
Fix this by getting the next padata before the squeue->serial lock
is released.
In order to make this possible, simplify padata_reorder by only
calling it once the next padata arrives. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix use-after-free in vhci_flush()
syzbot reported use-after-free in vhci_flush() without repro. [0]
From the splat, a thread close()d a vhci file descriptor while
its device was being used by iotcl() on another thread.
Once the last fd refcnt is released, vhci_release() calls
hci_unregister_dev(), hci_free_dev(), and kfree() for struct
vhci_data, which is set to hci_dev->dev->driver_data.
The problem is that there is no synchronisation after unlinking
hdev from hci_dev_list in hci_unregister_dev(). There might be
another thread still accessing the hdev which was fetched before
the unlink operation.
We can use SRCU for such synchronisation.
Let's run hci_dev_reset() under SRCU and wait for its completion
in hci_unregister_dev().
Another option would be to restore hci_dev->destruct(), which was
removed in commit 587ae086f6e4 ("Bluetooth: Remove unused
hci-destruct cb"). However, this would not be a good solution, as
we should not run hci_unregister_dev() while there are in-flight
ioctl() requests, which could lead to another data-race KCSAN splat.
Note that other drivers seem to have the same problem, for exmaple,
virtbt_remove().
[0]:
BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline]
BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937
Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718
CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xd2/0x2b0 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline]
skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937
skb_queue_purge include/linux/skbuff.h:3368 [inline]
vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69
hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline]
hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592
sock_do_ioctl+0xd9/0x300 net/socket.c:1190
sock_ioctl+0x576/0x790 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf5b98e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929
RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009
RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528
</TASK>
Allocated by task 6535:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635
misc_open+0x2bc/0x330 drivers/char/misc.c:161
chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
do_dentry_open+0xdf0/0x1970 fs/open.c:964
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/name
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix use-after free in init error and remove paths
devm_blk_crypto_profile_init() registers a cleanup handler to run when
the associated (platform-) device is being released. For UFS, the
crypto private data and pointers are stored as part of the ufs_hba's
data structure 'struct ufs_hba::crypto_profile'. This structure is
allocated as part of the underlying ufshcd and therefore Scsi_host
allocation.
During driver release or during error handling in ufshcd_pltfrm_init(),
this structure is released as part of ufshcd_dealloc_host() before the
(platform-) device associated with the crypto call above is released.
Once this device is released, the crypto cleanup code will run, using
the just-released 'struct ufs_hba::crypto_profile'. This causes a
use-after-free situation:
Call trace:
kfree+0x60/0x2d8 (P)
kvfree+0x44/0x60
blk_crypto_profile_destroy_callback+0x28/0x70
devm_action_release+0x1c/0x30
release_nodes+0x6c/0x108
devres_release_all+0x98/0x100
device_unbind_cleanup+0x20/0x70
really_probe+0x218/0x2d0
In other words, the initialisation code flow is:
platform-device probe
ufshcd_pltfrm_init()
ufshcd_alloc_host()
scsi_host_alloc()
allocation of struct ufs_hba
creation of scsi-host devices
devm_blk_crypto_profile_init()
devm registration of cleanup handler using platform-device
and during error handling of ufshcd_pltfrm_init() or during driver
removal:
ufshcd_dealloc_host()
scsi_host_put()
put_device(scsi-host)
release of struct ufs_hba
put_device(platform-device)
crypto cleanup handler
To fix this use-after free, change ufshcd_alloc_host() to register a
devres action to automatically cleanup the underlying SCSI device on
ufshcd destruction, without requiring explicit calls to
ufshcd_dealloc_host(). This way:
* the crypto profile and all other ufs_hba-owned resources are
destroyed before SCSI (as they've been registered after)
* a memleak is plugged in tc-dwc-g210-pci.c remove() as a
side-effect
* EXPORT_SYMBOL_GPL(ufshcd_dealloc_host) can be removed fully as
it's not needed anymore
* no future drivers using ufshcd_alloc_host() could ever forget
adding the cleanup |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: Avoid a bad reference count on CPU node
In the parse_perf_domain function, if the call to
of_parse_phandle_with_args returns an error, then the reference to the
CPU device node that was acquired at the start of the function would not
be properly decremented.
Address this by declaring the variable with the __free(device_node)
cleanup attribute. |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: efifb: Register sysfs groups through driver core
The driver core can register and cleanup sysfs groups already.
Make use of that functionality to simplify the error handling and
cleanup.
Also avoid a UAF race during unregistering where the sysctl attributes
were usable after the info struct was freed. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix potential UAF in smb2_is_valid_oplock_break()
Skip sessions that are being teared down (status == SES_EXITING) to
avoid UAF. |
