In the Linux kernel, the following vulnerability has been resolved:
scsi: libsas: Fix use-after-free bug in smp_execute_task_sg()
When executing SMP task failed, the smp_execute_task_sg() calls del_timer()
to delete "slow_task->timer". However, if the timer handler
sas_task_internal_timedout() is running, the del_timer() in
smp_execute_task_sg() will not stop it and a UAF will happen. The process
is shown below:
(thread 1) | (thread 2)
smp_execute_task_sg() | sas_task_internal_timedout()
... |
del_timer() |
... | ...
sas_free_task(task) |
kfree(task->slow_task) //FREE|
| task->slow_task->... //USE
Fix by calling del_timer_sync() in smp_execute_task_sg(), which makes sure
the timer handler have finished before the "task->slow_task" is
deallocated.
In the Linux kernel, the following vulnerability has been resolved:
ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()
There is an use-after-free reported by KASAN:
BUG: KASAN: use-after-free in acpi_ut_remove_reference+0x3b/0x82
Read of size 1 at addr ffff888112afc460 by task modprobe/2111
CPU: 0 PID: 2111 Comm: modprobe Not tainted 6.1.0-rc7-dirty
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
Call Trace:
<TASK>
kasan_report+0xae/0xe0
acpi_ut_remove_reference+0x3b/0x82
acpi_ut_copy_iobject_to_iobject+0x3be/0x3d5
acpi_ds_store_object_to_local+0x15d/0x3a0
acpi_ex_store+0x78d/0x7fd
acpi_ex_opcode_1A_1T_1R+0xbe4/0xf9b
acpi_ps_parse_aml+0x217/0x8d5
...
</TASK>
The root cause of the problem is that the acpi_operand_object
is freed when acpi_ut_walk_package_tree() fails in
acpi_ut_copy_ipackage_to_ipackage(), lead to repeated release in
acpi_ut_copy_iobject_to_iobject(). The problem was introduced
by "8aa5e56eeb61" commit, this commit is to fix memory leak in
acpi_ut_copy_iobject_to_iobject(), repeatedly adding remove
operation, lead to "acpi_operand_object" used after free.
Fix it by removing acpi_ut_remove_reference() in
acpi_ut_copy_ipackage_to_ipackage(). acpi_ut_copy_ipackage_to_ipackage()
is called to copy an internal package object into another internal
package object, when it fails, the memory of acpi_operand_object
should be freed by the caller.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix UBSAN shift-out-of-bounds warning
If get_num_sdma_queues or get_num_xgmi_sdma_queues is 0, we end up
doing a shift operation where the number of bits shifted equals
number of bits in the operand. This behaviour is undefined.
Set num_sdma_queues or num_xgmi_sdma_queues to ULLONG_MAX, if the
count is >= number of bits in the operand.
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1472
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix race condition validating r_parent before applying state
Add validation to ensure the cached parent directory inode matches the
directory info in MDS replies. This prevents client-side race conditions
where concurrent operations (e.g. rename) cause r_parent to become stale
between request initiation and reply processing, which could lead to
applying state changes to incorrect directory inodes.
[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to
move CEPH_CAP_PIN reference when r_parent is updated:
When the parent directory lock is not held, req->r_parent can become
stale and is updated to point to the correct inode. However, the
associated CEPH_CAP_PIN reference was not being adjusted. The
CEPH_CAP_PIN is a reference on an inode that is tracked for
accounting purposes. Moving this pin is important to keep the
accounting balanced. When the pin was not moved from the old parent
to the new one, it created two problems: The reference on the old,
stale parent was never released, causing a reference leak.
A reference for the new parent was never acquired, creating the risk
of a reference underflow later in ceph_mdsc_release_request(). This
patch corrects the logic by releasing the pin from the old parent and
acquiring it for the new parent when r_parent is switched. This
ensures reference accounting stays balanced. ]
In the Linux kernel, the following vulnerability has been resolved:
net: phylink: add lock for serializing concurrent pl->phydev writes with resolver
Currently phylink_resolve() protects itself against concurrent
phylink_bringup_phy() or phylink_disconnect_phy() calls which modify
pl->phydev by relying on pl->state_mutex.
The problem is that in phylink_resolve(), pl->state_mutex is in a lock
inversion state with pl->phydev->lock. So pl->phydev->lock needs to be
acquired prior to pl->state_mutex. But that requires dereferencing
pl->phydev in the first place, and without pl->state_mutex, that is
racy.
Hence the reason for the extra lock. Currently it is redundant, but it
will serve a functional purpose once mutex_lock(&phy->lock) will be
moved outside of the mutex_lock(&pl->state_mutex) section.
Another alternative considered would have been to let phylink_resolve()
acquire the rtnl_mutex, which is also held when phylink_bringup_phy()
and phylink_disconnect_phy() are called. But since phylink_disconnect_phy()
runs under rtnl_lock(), it would deadlock with phylink_resolve() when
calling flush_work(&pl->resolve). Additionally, it would have been
undesirable because it would have unnecessarily blocked many other call
paths as well in the entire kernel, so the smaller-scoped lock was
preferred.
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work
The brcmf_btcoex_detach() only shuts down the btcoex timer, if the
flag timer_on is false. However, the brcmf_btcoex_timerfunc(), which
runs as timer handler, sets timer_on to false. This creates critical
race conditions:
1.If brcmf_btcoex_detach() is called while brcmf_btcoex_timerfunc()
is executing, it may observe timer_on as false and skip the call to
timer_shutdown_sync().
2.The brcmf_btcoex_timerfunc() may then reschedule the brcmf_btcoex_info
worker after the cancel_work_sync() has been executed, resulting in
use-after-free bugs.
The use-after-free bugs occur in two distinct scenarios, depending on
the timing of when the brcmf_btcoex_info struct is freed relative to
the execution of its worker thread.
Scenario 1: Freed before the worker is scheduled
The brcmf_btcoex_info is deallocated before the worker is scheduled.
A race condition can occur when schedule_work(&bt_local->work) is
called after the target memory has been freed. The sequence of events
is detailed below:
CPU0 | CPU1
brcmf_btcoex_detach | brcmf_btcoex_timerfunc
| bt_local->timer_on = false;
if (cfg->btcoex->timer_on) |
... |
cancel_work_sync(); |
... |
kfree(cfg->btcoex); // FREE |
| schedule_work(&bt_local->work); // USE
Scenario 2: Freed after the worker is scheduled
The brcmf_btcoex_info is freed after the worker has been scheduled
but before or during its execution. In this case, statements within
the brcmf_btcoex_handler() — such as the container_of macro and
subsequent dereferences of the brcmf_btcoex_info object will cause
a use-after-free access. The following timeline illustrates this
scenario:
CPU0 | CPU1
brcmf_btcoex_detach | brcmf_btcoex_timerfunc
| bt_local->timer_on = false;
if (cfg->btcoex->timer_on) |
... |
cancel_work_sync(); |
... | schedule_work(); // Reschedule
|
kfree(cfg->btcoex); // FREE | brcmf_btcoex_handler() // Worker
/* | btci = container_of(....); // USE
The kfree() above could | ...
also occur at any point | btci-> // USE
during the worker's execution|
*/ |
To resolve the race conditions, drop the conditional check and call
timer_shutdown_sync() directly. It can deactivate the timer reliably,
regardless of its current state. Once stopped, the timer_on state is
then set to false.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: don't reset unchangable mount option in f2fs_remount()
syzbot reports a bug as below:
general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942
Call Trace:
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
__raw_write_lock include/linux/rwlock_api_smp.h:209 [inline]
_raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300
__drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100
f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116
f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664
f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838
vfs_fallocate+0x54b/0x6b0 fs/open.c:324
ksys_fallocate fs/open.c:347 [inline]
__do_sys_fallocate fs/open.c:355 [inline]
__se_sys_fallocate fs/open.c:353 [inline]
__x64_sys_fallocate+0xbd/0x100 fs/open.c:353
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is race condition as below:
- since it tries to remount rw filesystem, so that do_remount won't
call sb_prepare_remount_readonly to block fallocate, there may be race
condition in between remount and fallocate.
- in f2fs_remount(), default_options() will reset mount option to default
one, and then update it based on result of parse_options(), so there is
a hole which race condition can happen.
Thread A Thread B
- f2fs_fill_super
- parse_options
- clear_opt(READ_EXTENT_CACHE)
- f2fs_remount
- default_options
- set_opt(READ_EXTENT_CACHE)
- f2fs_fallocate
- f2fs_insert_range
- f2fs_drop_extent_tree
- __drop_extent_tree
- __may_extent_tree
- test_opt(READ_EXTENT_CACHE) return true
- write_lock(&et->lock) access NULL pointer
- parse_options
- clear_opt(READ_EXTENT_CACHE)
In the Linux kernel, the following vulnerability has been resolved:
mfd: arizona: Use pm_runtime_resume_and_get() to prevent refcnt leak
In arizona_clk32k_enable(), we should use pm_runtime_resume_and_get()
as pm_runtime_get_sync() will increase the refcnt even when it
returns an error.
In the Linux kernel, the following vulnerability has been resolved:
scsi: ses: Handle enclosure with just a primary component gracefully
This reverts commit 3fe97ff3d949 ("scsi: ses: Don't attach if enclosure
has no components") and introduces proper handling of case where there are
no detected secondary components, but primary component (enumerated in
num_enclosures) does exist. That fix was originally proposed by Ding Hui
<dinghui@sangfor.com.cn>.
Completely ignoring devices that have one primary enclosure and no
secondary one results in ses_intf_add() bailing completely
scsi 2:0:0:254: enclosure has no enumerated components
scsi 2:0:0:254: Failed to bind enclosure -12ven in valid configurations such
even on valid configurations with 1 primary and 0 secondary enclosures as
below:
# sg_ses /dev/sg0
3PARdata SES 3321
Supported diagnostic pages:
Supported Diagnostic Pages [sdp] [0x0]
Configuration (SES) [cf] [0x1]
Short Enclosure Status (SES) [ses] [0x8]
# sg_ses -p cf /dev/sg0
3PARdata SES 3321
Configuration diagnostic page:
number of secondary subenclosures: 0
generation code: 0x0
enclosure descriptor list
Subenclosure identifier: 0 [primary]
relative ES process id: 0, number of ES processes: 1
number of type descriptor headers: 1
enclosure logical identifier (hex): 20000002ac02068d
enclosure vendor: 3PARdata product: VV rev: 3321
type descriptor header and text list
Element type: Unspecified, subenclosure id: 0
number of possible elements: 1
The changelog for the original fix follows
=====
We can get a crash when disconnecting the iSCSI session,
the call trace like this:
[ffff00002a00fb70] kfree at ffff00000830e224
[ffff00002a00fba0] ses_intf_remove at ffff000001f200e4
[ffff00002a00fbd0] device_del at ffff0000086b6a98
[ffff00002a00fc50] device_unregister at ffff0000086b6d58
[ffff00002a00fc70] __scsi_remove_device at ffff00000870608c
[ffff00002a00fca0] scsi_remove_device at ffff000008706134
[ffff00002a00fcc0] __scsi_remove_target at ffff0000087062e4
[ffff00002a00fd10] scsi_remove_target at ffff0000087064c0
[ffff00002a00fd70] __iscsi_unbind_session at ffff000001c872c4
[ffff00002a00fdb0] process_one_work at ffff00000810f35c
[ffff00002a00fe00] worker_thread at ffff00000810f648
[ffff00002a00fe70] kthread at ffff000008116e98
In ses_intf_add, components count could be 0, and kcalloc 0 size scomp,
but not saved in edev->component[i].scratch
In this situation, edev->component[0].scratch is an invalid pointer,
when kfree it in ses_intf_remove_enclosure, a crash like above would happen
The call trace also could be other random cases when kfree cannot catch
the invalid pointer
We should not use edev->component[] array when the components count is 0
We also need check index when use edev->component[] array in
ses_enclosure_data_process
=====
In the Linux kernel, the following vulnerability has been resolved:
firewire: net: fix use after free in fwnet_finish_incoming_packet()
The netif_rx() function frees the skb so we can't dereference it to
save the skb->len.