Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
audit: fix possible null-pointer dereference in audit_filter_rules
Fix possible null-pointer dereference in audit_filter_rules.
audit_filter_rules() error: we previously assumed 'ctx' could be null
In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
In commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in
C") kvm_start_guest() became idle_kvm_start_guest(). The old code
allocated a stack frame on the emergency stack, but didn't use the
frame to store anything, and also didn't store anything in its caller's
frame.
idle_kvm_start_guest() on the other hand is written more like a normal C
function, it creates a frame on entry, and also stores CR/LR into its
callers frame (per the ABI). The problem is that there is no caller
frame on the emergency stack.
The emergency stack for a given CPU is allocated with:
paca_ptrs[i]->emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
So emergency_sp actually points to the first address above the emergency
stack allocation for a given CPU, we must not store above it without
first decrementing it to create a frame. This is different to the
regular kernel stack, paca->kstack, which is initialised to point at an
initial frame that is ready to use.
idle_kvm_start_guest() stores the backchain, CR and LR all of which
write outside the allocation for the emergency stack. It then creates a
stack frame and saves the non-volatile registers. Unfortunately the
frame it creates is not large enough to fit the non-volatiles, and so
the saving of the non-volatile registers also writes outside the
emergency stack allocation.
The end result is that we corrupt whatever is at 0-24 bytes, and 112-248
bytes above the emergency stack allocation.
In practice this has gone unnoticed because the memory immediately above
the emergency stack happens to be used for other stack allocations,
either another CPUs mc_emergency_sp or an IRQ stack. See the order of
calls to irqstack_early_init() and emergency_stack_init().
The low addresses of another stack are the top of that stack, and so are
only used if that stack is under extreme pressue, which essentially
never happens in practice - and if it did there's a high likelyhood we'd
crash due to that stack overflowing.
Still, we shouldn't be corrupting someone else's stack, and it is purely
luck that we aren't corrupting something else.
To fix it we save CR/LR into the caller's frame using the existing r1 on
entry, we then create a SWITCH_FRAME_SIZE frame (which has space for
pt_regs) on the emergency stack with the backchain pointing to the
existing stack, and then finally we switch to the new frame on the
emergency stack.
In the Linux kernel, the following vulnerability has been resolved:
mm, slub: fix potential memoryleak in kmem_cache_open()
In error path, the random_seq of slub cache might be leaked. Fix this
by using __kmem_cache_release() to release all the relevant resources.
In the Linux kernel, the following vulnerability has been resolved:
kunit: fix reference count leak in kfree_at_end
The reference counting issue happens in the normal path of
kfree_at_end(). When kunit_alloc_and_get_resource() is invoked, the
function forgets to handle the returned resource object, whose refcount
increased inside, causing a refcount leak.
Fix this issue by calling kunit_alloc_resource() instead of
kunit_alloc_and_get_resource().
Fixed the following when applying:
Shuah Khan <skhan@linuxfoundation.org>
CHECK: Alignment should match open parenthesis
+ kunit_alloc_resource(test, NULL, kfree_res_free, GFP_KERNEL,
(void *)to_free);
In the Linux kernel, the following vulnerability has been resolved:
isdn: mISDN: Fix sleeping function called from invalid context
The driver can call card->isac.release() function from an atomic
context.
Fix this by calling this function after releasing the lock.
The following log reveals it:
[ 44.168226 ] BUG: sleeping function called from invalid context at kernel/workqueue.c:3018
[ 44.168941 ] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 5475, name: modprobe
[ 44.169574 ] INFO: lockdep is turned off.
[ 44.169899 ] irq event stamp: 0
[ 44.170160 ] hardirqs last enabled at (0): [<0000000000000000>] 0x0
[ 44.170627 ] hardirqs last disabled at (0): [<ffffffff814209ed>] copy_process+0x132d/0x3e00
[ 44.171240 ] softirqs last enabled at (0): [<ffffffff81420a1a>] copy_process+0x135a/0x3e00
[ 44.171852 ] softirqs last disabled at (0): [<0000000000000000>] 0x0
[ 44.172318 ] Preemption disabled at:
[ 44.172320 ] [<ffffffffa009b0a9>] nj_release+0x69/0x500 [netjet]
[ 44.174441 ] Call Trace:
[ 44.174630 ] dump_stack_lvl+0xa8/0xd1
[ 44.174912 ] dump_stack+0x15/0x17
[ 44.175166 ] ___might_sleep+0x3a2/0x510
[ 44.175459 ] ? nj_release+0x69/0x500 [netjet]
[ 44.175791 ] __might_sleep+0x82/0xe0
[ 44.176063 ] ? start_flush_work+0x20/0x7b0
[ 44.176375 ] start_flush_work+0x33/0x7b0
[ 44.176672 ] ? trace_irq_enable_rcuidle+0x85/0x170
[ 44.177034 ] ? kasan_quarantine_put+0xaa/0x1f0
[ 44.177372 ] ? kasan_quarantine_put+0xaa/0x1f0
[ 44.177711 ] __flush_work+0x11a/0x1a0
[ 44.177991 ] ? flush_work+0x20/0x20
[ 44.178257 ] ? lock_release+0x13c/0x8f0
[ 44.178550 ] ? __kasan_check_write+0x14/0x20
[ 44.178872 ] ? do_raw_spin_lock+0x148/0x360
[ 44.179187 ] ? read_lock_is_recursive+0x20/0x20
[ 44.179530 ] ? __kasan_check_read+0x11/0x20
[ 44.179846 ] ? do_raw_spin_unlock+0x55/0x900
[ 44.180168 ] ? ____kasan_slab_free+0x116/0x140
[ 44.180505 ] ? _raw_spin_unlock_irqrestore+0x41/0x60
[ 44.180878 ] ? skb_queue_purge+0x1a3/0x1c0
[ 44.181189 ] ? kfree+0x13e/0x290
[ 44.181438 ] flush_work+0x17/0x20
[ 44.181695 ] mISDN_freedchannel+0xe8/0x100
[ 44.182006 ] isac_release+0x210/0x260 [mISDNipac]
[ 44.182366 ] nj_release+0xf6/0x500 [netjet]
[ 44.182685 ] nj_remove+0x48/0x70 [netjet]
[ 44.182989 ] pci_device_remove+0xa9/0x250
In the Linux kernel, the following vulnerability has been resolved:
mm, slub: fix potential use-after-free in slab_debugfs_fops
When sysfs_slab_add failed, we shouldn't call debugfs_slab_add() for s
because s will be freed soon. And slab_debugfs_fops will use s later
leading to a use-after-free.
In the Linux kernel, the following vulnerability has been resolved:
drm: mxsfb: Fix NULL pointer dereference crash on unload
The mxsfb->crtc.funcs may already be NULL when unloading the driver,
in which case calling mxsfb_irq_disable() via drm_irq_uninstall() from
mxsfb_unload() leads to NULL pointer dereference.
Since all we care about is masking the IRQ and mxsfb->base is still
valid, just use that to clear and mask the IRQ.
In the Linux kernel, the following vulnerability has been resolved:
ice: fix locking for Tx timestamp tracking flush
Commit 4dd0d5c33c3e ("ice: add lock around Tx timestamp tracker flush")
added a lock around the Tx timestamp tracker flow which is used to
cleanup any left over SKBs and prepare for device removal.
This lock is problematic because it is being held around a call to
ice_clear_phy_tstamp. The clear function takes a mutex to send a PHY
write command to firmware. This could lead to a deadlock if the mutex
actually sleeps, and causes the following warning on a kernel with
preemption debugging enabled:
[ 715.419426] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:573
[ 715.427900] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3100, name: rmmod
[ 715.435652] INFO: lockdep is turned off.
[ 715.439591] Preemption disabled at:
[ 715.439594] [<0000000000000000>] 0x0
[ 715.446678] CPU: 52 PID: 3100 Comm: rmmod Tainted: G W OE 5.15.0-rc4+ #42 bdd7ec3018e725f159ca0d372ce8c2c0e784891c
[ 715.458058] Hardware name: Intel Corporation S2600STQ/S2600STQ, BIOS SE5C620.86B.02.01.0010.010620200716 01/06/2020
[ 715.468483] Call Trace:
[ 715.470940] dump_stack_lvl+0x6a/0x9a
[ 715.474613] ___might_sleep.cold+0x224/0x26a
[ 715.478895] __mutex_lock+0xb3/0x1440
[ 715.482569] ? stack_depot_save+0x378/0x500
[ 715.486763] ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.494979] ? kfree+0xc1/0x520
[ 715.498128] ? mutex_lock_io_nested+0x12a0/0x12a0
[ 715.502837] ? kasan_set_free_info+0x20/0x30
[ 715.507110] ? __kasan_slab_free+0x10b/0x140
[ 715.511385] ? slab_free_freelist_hook+0xc7/0x220
[ 715.516092] ? kfree+0xc1/0x520
[ 715.519235] ? ice_deinit_lag+0x16c/0x220 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.527359] ? ice_remove+0x1cf/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.535133] ? pci_device_remove+0xab/0x1d0
[ 715.539318] ? __device_release_driver+0x35b/0x690
[ 715.544110] ? driver_detach+0x214/0x2f0
[ 715.548035] ? bus_remove_driver+0x11d/0x2f0
[ 715.552309] ? pci_unregister_driver+0x26/0x250
[ 715.556840] ? ice_module_exit+0xc/0x2f [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.564799] ? __do_sys_delete_module.constprop.0+0x2d8/0x4e0
[ 715.570554] ? do_syscall_64+0x3b/0x90
[ 715.574303] ? entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 715.579529] ? start_flush_work+0x542/0x8f0
[ 715.583719] ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.591923] ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.599960] ? wait_for_completion_io+0x250/0x250
[ 715.604662] ? lock_acquire+0x196/0x200
[ 715.608504] ? do_raw_spin_trylock+0xa5/0x160
[ 715.612864] ice_sbq_rw_reg+0x1e6/0x2f0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.620813] ? ice_reset+0x130/0x130 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.628497] ? __debug_check_no_obj_freed+0x1e8/0x3c0
[ 715.633550] ? trace_hardirqs_on+0x1c/0x130
[ 715.637748] ice_write_phy_reg_e810+0x70/0xf0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.646220] ? do_raw_spin_trylock+0xa5/0x160
[ 715.650581] ? ice_ptp_release+0x910/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.658797] ? ice_ptp_release+0x255/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.667013] ice_clear_phy_tstamp+0x2c/0x110 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.675403] ice_ptp_release+0x408/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.683440] ice_remove+0x560/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d]
[ 715.691037] ? _raw_spin_unlock_irqrestore+0x46/0x73
[ 715.696005] pci_device_remove+0xab/0x1d0
[ 715.700018] __device_release_driver+0x35b/0x690
[ 715.704637] driver_detach+0x214/0x2f0
[ 715.708389] bus_remove_driver+0x11d/0x2f0
[ 715.712489] pci_unregister_driver+0x26/0x250
[ 71
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Fix host stage-2 PGD refcount
The KVM page-table library refcounts the pages of concatenated stage-2
PGDs individually. However, when running KVM in protected mode, the
host's stage-2 PGD is currently managed by EL2 as a single high-order
compound page, which can cause the refcount of the tail pages to reach 0
when they shouldn't, hence corrupting the page-table.
Fix this by introducing a new hyp_split_page() helper in the EL2 page
allocator (matching the kernel's split_page() function), and make use of
it from host_s2_zalloc_pages_exact().
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
Currently, when the rule related to IDLETIMER is added, idletimer_tg timer
structure is initialized by kmalloc on executing idletimer_tg_create
function. However, in this process timer->timer_type is not defined to
a specific value. Thus, timer->timer_type has garbage value and it occurs
kernel panic. So, this commit fixes the panic by initializing
timer->timer_type using kzalloc instead of kmalloc.
Test commands:
# iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test
$ cat /sys/class/xt_idletimer/timers/test
Killed
Splat looks like:
BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70
Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917
CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
dump_stack_lvl+0x6e/0x9c
kasan_report.cold+0x112/0x117
? alarm_expires_remaining+0x49/0x70
__asan_load8+0x86/0xb0
alarm_expires_remaining+0x49/0x70
idletimer_tg_show+0xe5/0x19b [xt_IDLETIMER 11219304af9316a21bee5ba9d58f76a6b9bccc6d]
dev_attr_show+0x3c/0x60
sysfs_kf_seq_show+0x11d/0x1f0
? device_remove_bin_file+0x20/0x20
kernfs_seq_show+0xa4/0xb0
seq_read_iter+0x29c/0x750
kernfs_fop_read_iter+0x25a/0x2c0
? __fsnotify_parent+0x3d1/0x570
? iov_iter_init+0x70/0x90
new_sync_read+0x2a7/0x3d0
? __x64_sys_llseek+0x230/0x230
? rw_verify_area+0x81/0x150
vfs_read+0x17b/0x240
ksys_read+0xd9/0x180
? vfs_write+0x460/0x460
? do_syscall_64+0x16/0xc0
? lockdep_hardirqs_on+0x79/0x120
__x64_sys_read+0x43/0x50
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0cdc819142
Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007fff28eee5b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f0cdc819142
RDX: 0000000000020000 RSI: 00007f0cdc032000 RDI: 0000000000000003
RBP: 00007f0cdc032000 R08: 00007f0cdc031010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 00005607e9ee31f0
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000