Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
IB/mlx5: Fix init stage error handling to avoid double free of same QP and UAF
In the unlikely event that workqueue allocation fails and returns NULL in
mlx5_mkey_cache_init(), delete the call to
mlx5r_umr_resource_cleanup() (which frees the QP) in
mlx5_ib_stage_post_ib_reg_umr_init(). This will avoid attempted double
free of the same QP when __mlx5_ib_add() does its cleanup.
Resolves a splat:
Syzkaller reported a UAF in ib_destroy_qp_user
workqueue: Failed to create a rescuer kthread for wq "mkey_cache": -EINTR
infiniband mlx5_0: mlx5_mkey_cache_init:981:(pid 1642):
failed to create work queue
infiniband mlx5_0: mlx5_ib_stage_post_ib_reg_umr_init:4075:(pid 1642):
mr cache init failed -12
==================================================================
BUG: KASAN: slab-use-after-free in ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073)
Read of size 8 at addr ffff88810da310a8 by task repro_upstream/1642
Call Trace:
<TASK>
kasan_report (mm/kasan/report.c:590)
ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073)
mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198)
__mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4178)
mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
...
</TASK>
Allocated by task 1642:
__kmalloc (./include/linux/kasan.h:198 mm/slab_common.c:1026
mm/slab_common.c:1039)
create_qp (./include/linux/slab.h:603 ./include/linux/slab.h:720
./include/rdma/ib_verbs.h:2795 drivers/infiniband/core/verbs.c:1209)
ib_create_qp_kernel (drivers/infiniband/core/verbs.c:1347)
mlx5r_umr_resource_init (drivers/infiniband/hw/mlx5/umr.c:164)
mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4070)
__mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168)
mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
...
Freed by task 1642:
__kmem_cache_free (mm/slub.c:1826 mm/slub.c:3809 mm/slub.c:3822)
ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2112)
mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198)
mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4076
drivers/infiniband/hw/mlx5/main.c:4065)
__mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168)
mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
...
In the Linux kernel, the following vulnerability has been resolved:
f2fs: compress: fix to avoid use-after-free on dic
Call trace:
__memcpy+0x128/0x250
f2fs_read_multi_pages+0x940/0xf7c
f2fs_mpage_readpages+0x5a8/0x624
f2fs_readahead+0x5c/0x110
page_cache_ra_unbounded+0x1b8/0x590
do_sync_mmap_readahead+0x1dc/0x2e4
filemap_fault+0x254/0xa8c
f2fs_filemap_fault+0x2c/0x104
__do_fault+0x7c/0x238
do_handle_mm_fault+0x11bc/0x2d14
do_mem_abort+0x3a8/0x1004
el0_da+0x3c/0xa0
el0t_64_sync_handler+0xc4/0xec
el0t_64_sync+0x1b4/0x1b8
In f2fs_read_multi_pages(), once f2fs_decompress_cluster() was called if
we hit cached page in compress_inode's cache, dic may be released, it needs
break the loop rather than continuing it, in order to avoid accessing
invalid dic pointer.
In the Linux kernel, the following vulnerability has been resolved:
padata: Fix refcnt handling in padata_free_shell()
In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead
to system UAF (Use-After-Free) issues. Due to the lengthy analysis of
the pcrypt_aead01 function call, I'll describe the problem scenario
using a simplified model:
Suppose there's a user of padata named `user_function` that adheres to
the padata requirement of calling `padata_free_shell` after `serial()`
has been invoked, as demonstrated in the following code:
```c
struct request {
struct padata_priv padata;
struct completion *done;
};
void parallel(struct padata_priv *padata) {
do_something();
}
void serial(struct padata_priv *padata) {
struct request *request = container_of(padata,
struct request,
padata);
complete(request->done);
}
void user_function() {
DECLARE_COMPLETION(done)
padata->parallel = parallel;
padata->serial = serial;
padata_do_parallel();
wait_for_completion(&done);
padata_free_shell();
}
```
In the corresponding padata.c file, there's the following code:
```c
static void padata_serial_worker(struct work_struct *serial_work) {
...
cnt = 0;
while (!list_empty(&local_list)) {
...
padata->serial(padata);
cnt++;
}
local_bh_enable();
if (refcount_sub_and_test(cnt, &pd->refcnt))
padata_free_pd(pd);
}
```
Because of the high system load and the accumulation of unexecuted
softirq at this moment, `local_bh_enable()` in padata takes longer
to execute than usual. Subsequently, when accessing `pd->refcnt`,
`pd` has already been released by `padata_free_shell()`, resulting
in a UAF issue with `pd->refcnt`.
The fix is straightforward: add `refcount_dec_and_test` before calling
`padata_free_pd` in `padata_free_shell`.
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:
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).