Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency
In _dwc2_hcd_urb_enqueue(), "urb->hcpriv = NULL" is executed without
holding the lock "hsotg->lock". In _dwc2_hcd_urb_dequeue():
spin_lock_irqsave(&hsotg->lock, flags);
...
if (!urb->hcpriv) {
dev_dbg(hsotg->dev, "## urb->hcpriv is NULL ##\n");
goto out;
}
rc = dwc2_hcd_urb_dequeue(hsotg, urb->hcpriv); // Use urb->hcpriv
...
out:
spin_unlock_irqrestore(&hsotg->lock, flags);
When _dwc2_hcd_urb_enqueue() and _dwc2_hcd_urb_dequeue() are
concurrently executed, the NULL check of "urb->hcpriv" can be executed
before "urb->hcpriv = NULL". After urb->hcpriv is NULL, it can be used
in the function call to dwc2_hcd_urb_dequeue(), which can cause a NULL
pointer dereference.
This possible bug is found by an experimental static analysis tool
developed by myself. This tool analyzes the locking APIs to extract
function pairs that can be concurrently executed, and then analyzes the
instructions in the paired functions to identify possible concurrency
bugs including data races and atomicity violations. The above possible
bug is reported, when my tool analyzes the source code of Linux 6.5.
To fix this possible bug, "urb->hcpriv = NULL" should be executed with
holding the lock "hsotg->lock". After using this patch, my tool never
reports the possible bug, with the kernelconfiguration allyesconfig for
x86_64. Because I have no associated hardware, I cannot test the patch
in runtime testing, and just verify it according to the code logic.
In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: lt8912b: Fix crash on bridge detach
The lt8912b driver, in its bridge detach function, calls
drm_connector_unregister() and drm_connector_cleanup().
drm_connector_unregister() should be called only for connectors
explicitly registered with drm_connector_register(), which is not the
case in lt8912b.
The driver's drm_connector_funcs.destroy hook is set to
drm_connector_cleanup().
Thus the driver should not call either drm_connector_unregister() nor
drm_connector_cleanup() in its lt8912_bridge_detach(), as they cause a
crash on bridge detach:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=00000000858f3000
[0000000000000000] pgd=0800000085918003, p4d=0800000085918003, pud=0800000085431003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in: tidss(-) display_connector lontium_lt8912b tc358768 panel_lvds panel_simple drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks
CPU: 3 PID: 462 Comm: rmmod Tainted: G W 6.5.0-rc2+ #2
Hardware name: Toradex Verdin AM62 on Verdin Development Board (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drm_connector_cleanup+0x78/0x2d4 [drm]
lr : lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]
sp : ffff800082ed3a90
x29: ffff800082ed3a90 x28: ffff0000040c1940 x27: 0000000000000000
x26: 0000000000000000 x25: dead000000000122 x24: dead000000000122
x23: dead000000000100 x22: ffff000003fb6388 x21: 0000000000000000
x20: 0000000000000000 x19: ffff000003fb6260 x18: fffffffffffe56e8
x17: 0000000000000000 x16: 0010000000000000 x15: 0000000000000038
x14: 0000000000000000 x13: ffff800081914b48 x12: 000000000000040e
x11: 000000000000015a x10: ffff80008196ebb8 x9 : ffff800081914b48
x8 : 00000000ffffefff x7 : ffff0000040c1940 x6 : ffff80007aa649d0
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80008159e008
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
drm_connector_cleanup+0x78/0x2d4 [drm]
lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]
drm_bridge_detach+0x44/0x84 [drm]
drm_encoder_cleanup+0x40/0xb8 [drm]
drmm_encoder_alloc_release+0x1c/0x30 [drm]
drm_managed_release+0xac/0x148 [drm]
drm_dev_put.part.0+0x88/0xb8 [drm]
devm_drm_dev_init_release+0x14/0x24 [drm]
devm_action_release+0x14/0x20
release_nodes+0x5c/0x90
devres_release_all+0x8c/0xe0
device_unbind_cleanup+0x18/0x68
device_release_driver_internal+0x208/0x23c
driver_detach+0x4c/0x94
bus_remove_driver+0x70/0xf4
driver_unregister+0x30/0x60
platform_driver_unregister+0x14/0x20
tidss_platform_driver_exit+0x18/0xb2c [tidss]
__arm64_sys_delete_module+0x1a0/0x2b4
invoke_syscall+0x48/0x110
el0_svc_common.constprop.0+0x60/0x10c
do_el0_svc_compat+0x1c/0x40
el0_svc_compat+0x40/0xac
el0t_32_sync_handler+0xb0/0x138
el0t_32_sync+0x194/0x198
Code: 9104a276 f2fbd5b7 aa0203e1 91008af8 (f85c0420)
In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: Fix coverity issue with unintentional integer overflow
1. Instead of multiplying 2 variable of different types. Change to
assign a value of one variable and then multiply the other variable.
2. Add a int variable for multiplier calculation instead of calculating
different types multiplier with dma_addr_t variable directly.
In the Linux kernel, the following vulnerability has been resolved:
clk: mediatek: clk-mt7629: Add check for mtk_alloc_clk_data
Add the check for the return value of mtk_alloc_clk_data() in order to
avoid NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
perf: hisi: Fix use-after-free when register pmu fails
When we fail to register the uncore pmu, the pmu context may not been
allocated. The error handing will call cpuhp_state_remove_instance()
to call uncore pmu offline callback, which migrate the pmu context.
Since that's liable to lead to some kind of use-after-free.
Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been failed to register.
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Bail out early if the request AUX area is out of bound
When perf-record with a large AUX area, e.g 4GB, it fails with:
#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
failed to mmap with 12 (Cannot allocate memory)
and it reveals a WARNING with __alloc_pages():
------------[ cut here ]------------
WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248
Call trace:
__alloc_pages+0x1ec/0x248
__kmalloc_large_node+0xc0/0x1f8
__kmalloc_node+0x134/0x1e8
rb_alloc_aux+0xe0/0x298
perf_mmap+0x440/0x660
mmap_region+0x308/0x8a8
do_mmap+0x3c0/0x528
vm_mmap_pgoff+0xf4/0x1b8
ksys_mmap_pgoff+0x18c/0x218
__arm64_sys_mmap+0x38/0x58
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0x58/0x188
do_el0_svc+0x34/0x50
el0_svc+0x34/0x108
el0t_64_sync_handler+0xb8/0xc0
el0t_64_sync+0x1a4/0x1a8
'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to
maintains AUX trace pages. The allocated page for this array is physically
contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the
size of pointer array crosses the limitation set by MAX_ORDER, it reveals a
WARNING.
So bail out early with -ENOMEM if the request AUX area is out of bound,
e.g.:
#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
failed to mmap with 12 (Cannot allocate memory)
In the Linux kernel, the following vulnerability has been resolved:
locking/ww_mutex/test: Fix potential workqueue corruption
In some cases running with the test-ww_mutex code, I was seeing
odd behavior where sometimes it seemed flush_workqueue was
returning before all the work threads were finished.
Often this would cause strange crashes as the mutexes would be
freed while they were being used.
Looking at the code, there is a lifetime problem as the
controlling thread that spawns the work allocates the
"struct stress" structures that are passed to the workqueue
threads. Then when the workqueue threads are finished,
they free the stress struct that was passed to them.
Unfortunately the workqueue work_struct node is in the stress
struct. Which means the work_struct is freed before the work
thread returns and while flush_workqueue is waiting.
It seems like a better idea to have the controlling thread
both allocate and free the stress structures, so that we can
be sure we don't corrupt the workqueue by freeing the structure
prematurely.
So this patch reworks the test to do so, and with this change
I no longer see the early flush_workqueue returns.
In the Linux kernel, the following vulnerability has been resolved:
nbd: fix uaf in nbd_open
Commit 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and
blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set
disk->private_data as NULL as before. UAF may be triggered in nbd_open()
if someone tries to open nbd device right after nbd_put() since nbd has
been free in nbd_dev_remove().
Fix this by implementing ->free_disk and free private data in it.
In the Linux kernel, the following vulnerability has been resolved:
fbdev: imsttfb: fix a resource leak in probe
I've re-written the error handling but the bug is that if init_imstt()
fails we need to call iounmap(par->cmap_regs).
In the Linux kernel, the following vulnerability has been resolved:
drivers: perf: Do not broadcast to other cpus when starting a counter
This command:
$ perf record -e cycles:k -e instructions:k -c 10000 -m 64M dd if=/dev/zero of=/dev/null count=1000
gives rise to this kernel warning:
[ 444.364395] WARNING: CPU: 0 PID: 104 at kernel/smp.c:775 smp_call_function_many_cond+0x42c/0x436
[ 444.364515] Modules linked in:
[ 444.364657] CPU: 0 PID: 104 Comm: perf-exec Not tainted 6.6.0-rc6-00051-g391df82e8ec3-dirty #73
[ 444.364771] Hardware name: riscv-virtio,qemu (DT)
[ 444.364868] epc : smp_call_function_many_cond+0x42c/0x436
[ 444.364917] ra : on_each_cpu_cond_mask+0x20/0x32
[ 444.364948] epc : ffffffff8009f9e0 ra : ffffffff8009fa5a sp : ff20000000003800
[ 444.364966] gp : ffffffff81500aa0 tp : ff60000002b83000 t0 : ff200000000038c0
[ 444.364982] t1 : ffffffff815021f0 t2 : 000000000000001f s0 : ff200000000038b0
[ 444.364998] s1 : ff60000002c54d98 a0 : ff60000002a73940 a1 : 0000000000000000
[ 444.365013] a2 : 0000000000000000 a3 : 0000000000000003 a4 : 0000000000000100
[ 444.365029] a5 : 0000000000010100 a6 : 0000000000f00000 a7 : 0000000000000000
[ 444.365044] s2 : 0000000000000000 s3 : ffffffffffffffff s4 : ff60000002c54d98
[ 444.365060] s5 : ffffffff81539610 s6 : ffffffff80c20c48 s7 : 0000000000000000
[ 444.365075] s8 : 0000000000000000 s9 : 0000000000000001 s10: 0000000000000001
[ 444.365090] s11: ffffffff80099394 t3 : 0000000000000003 t4 : 00000000eac0c6e6
[ 444.365104] t5 : 0000000400000000 t6 : ff60000002e010d0
[ 444.365120] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
[ 444.365226] [<ffffffff8009f9e0>] smp_call_function_many_cond+0x42c/0x436
[ 444.365295] [<ffffffff8009fa5a>] on_each_cpu_cond_mask+0x20/0x32
[ 444.365311] [<ffffffff806e90dc>] pmu_sbi_ctr_start+0x7a/0xaa
[ 444.365327] [<ffffffff806e880c>] riscv_pmu_start+0x48/0x66
[ 444.365339] [<ffffffff8012111a>] perf_adjust_freq_unthr_context+0x196/0x1ac
[ 444.365356] [<ffffffff801237aa>] perf_event_task_tick+0x78/0x8c
[ 444.365368] [<ffffffff8003faf4>] scheduler_tick+0xe6/0x25e
[ 444.365383] [<ffffffff8008a042>] update_process_times+0x80/0x96
[ 444.365398] [<ffffffff800991ec>] tick_sched_handle+0x26/0x52
[ 444.365410] [<ffffffff800993e4>] tick_sched_timer+0x50/0x98
[ 444.365422] [<ffffffff8008a6aa>] __hrtimer_run_queues+0x126/0x18a
[ 444.365433] [<ffffffff8008b350>] hrtimer_interrupt+0xce/0x1da
[ 444.365444] [<ffffffff806cdc60>] riscv_timer_interrupt+0x30/0x3a
[ 444.365457] [<ffffffff8006afa6>] handle_percpu_devid_irq+0x80/0x114
[ 444.365470] [<ffffffff80065b82>] generic_handle_domain_irq+0x1c/0x2a
[ 444.365483] [<ffffffff8045faec>] riscv_intc_irq+0x2e/0x46
[ 444.365497] [<ffffffff808a9c62>] handle_riscv_irq+0x4a/0x74
[ 444.365521] [<ffffffff808aa760>] do_irq+0x7c/0x7e
[ 444.365796] ---[ end trace 0000000000000000 ]---
That's because the fix in commit 3fec323339a4 ("drivers: perf: Fix panic
in riscv SBI mmap support") was wrong since there is no need to broadcast
to other cpus when starting a counter, that's only needed in mmap when
the counters could have already been started on other cpus, so simply
remove this broadcast.