Security Vulnerabilities - CVEs Published In July 2024
In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()
Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().
It looks up `stt` from tablefd, but then continues to use it after doing
fdput() on the returned fd. After the fdput() the tablefd is free to be
closed by another thread. The close calls kvm_spapr_tce_release() and
then release_spapr_tce_table() (via call_rcu()) which frees `stt`.
Although there are calls to rcu_read_lock() in
kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent
the UAF, because `stt` is used outside the locked regions.
With an artifcial delay after the fdput() and a userspace program which
triggers the race, KASAN detects the UAF:
BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505
CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1
Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV
Call Trace:
dump_stack_lvl+0xb4/0x108 (unreliable)
print_report+0x2b4/0x6ec
kasan_report+0x118/0x2b0
__asan_load4+0xb8/0xd0
kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
kvm_vfio_set_attr+0x524/0xac0 [kvm]
kvm_device_ioctl+0x144/0x240 [kvm]
sys_ioctl+0x62c/0x1810
system_call_exception+0x190/0x440
system_call_vectored_common+0x15c/0x2ec
...
Freed by task 0:
...
kfree+0xec/0x3e0
release_spapr_tce_table+0xd4/0x11c [kvm]
rcu_core+0x568/0x16a0
handle_softirqs+0x23c/0x920
do_softirq_own_stack+0x6c/0x90
do_softirq_own_stack+0x58/0x90
__irq_exit_rcu+0x218/0x2d0
irq_exit+0x30/0x80
arch_local_irq_restore+0x128/0x230
arch_local_irq_enable+0x1c/0x30
cpuidle_enter_state+0x134/0x5cc
cpuidle_enter+0x6c/0xb0
call_cpuidle+0x7c/0x100
do_idle+0x394/0x410
cpu_startup_entry+0x60/0x70
start_secondary+0x3fc/0x410
start_secondary_prolog+0x10/0x14
Fix it by delaying the fdput() until `stt` is no longer in use, which
is effectively the entire function. To keep the patch minimal add a call
to fdput() at each of the existing return paths. Future work can convert
the function to goto or __cleanup style cleanup.
With the fix in place the test case no longer triggers the UAF.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: wext: add extra SIOCSIWSCAN data check
In 'cfg80211_wext_siwscan()', add extra check whether number of
channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed
IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix XDP program unloading while removing the driver
The commit 6533e558c650 ("i40e: Fix reset path while removing
the driver") introduced a new PF state "__I40E_IN_REMOVE" to block
modifying the XDP program while the driver is being removed.
Unfortunately, such a change is useful only if the ".ndo_bpf()"
callback was called out of the rmmod context because unloading the
existing XDP program is also a part of driver removing procedure.
In other words, from the rmmod context the driver is expected to
unload the XDP program without reporting any errors. Otherwise,
the kernel warning with callstack is printed out to dmesg.
Example failing scenario:
1. Load the i40e driver.
2. Load the XDP program.
3. Unload the i40e driver (using "rmmod" command).
The example kernel warning log:
[ +0.004646] WARNING: CPU: 94 PID: 10395 at net/core/dev.c:9290 unregister_netdevice_many_notify+0x7a9/0x870
[...]
[ +0.010959] RIP: 0010:unregister_netdevice_many_notify+0x7a9/0x870
[...]
[ +0.002726] Call Trace:
[ +0.002457] <TASK>
[ +0.002119] ? __warn+0x80/0x120
[ +0.003245] ? unregister_netdevice_many_notify+0x7a9/0x870
[ +0.005586] ? report_bug+0x164/0x190
[ +0.003678] ? handle_bug+0x3c/0x80
[ +0.003503] ? exc_invalid_op+0x17/0x70
[ +0.003846] ? asm_exc_invalid_op+0x1a/0x20
[ +0.004200] ? unregister_netdevice_many_notify+0x7a9/0x870
[ +0.005579] ? unregister_netdevice_many_notify+0x3cc/0x870
[ +0.005586] unregister_netdevice_queue+0xf7/0x140
[ +0.004806] unregister_netdev+0x1c/0x30
[ +0.003933] i40e_vsi_release+0x87/0x2f0 [i40e]
[ +0.004604] i40e_remove+0x1a1/0x420 [i40e]
[ +0.004220] pci_device_remove+0x3f/0xb0
[ +0.003943] device_release_driver_internal+0x19f/0x200
[ +0.005243] driver_detach+0x48/0x90
[ +0.003586] bus_remove_driver+0x6d/0xf0
[ +0.003939] pci_unregister_driver+0x2e/0xb0
[ +0.004278] i40e_exit_module+0x10/0x5f0 [i40e]
[ +0.004570] __do_sys_delete_module.isra.0+0x197/0x310
[ +0.005153] do_syscall_64+0x85/0x170
[ +0.003684] ? syscall_exit_to_user_mode+0x69/0x220
[ +0.004886] ? do_syscall_64+0x95/0x170
[ +0.003851] ? exc_page_fault+0x7e/0x180
[ +0.003932] entry_SYSCALL_64_after_hwframe+0x71/0x79
[ +0.005064] RIP: 0033:0x7f59dc9347cb
[ +0.003648] Code: 73 01 c3 48 8b 0d 65 16 0c 00 f7 d8 64 89 01 48 83
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 35 16 0c 00 f7 d8 64 89 01 48
[ +0.018753] RSP: 002b:00007ffffac99048 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ +0.007577] RAX: ffffffffffffffda RBX: 0000559b9bb2f6e0 RCX: 00007f59dc9347cb
[ +0.007140] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000559b9bb2f748
[ +0.007146] RBP: 00007ffffac99070 R08: 1999999999999999 R09: 0000000000000000
[ +0.007133] R10: 00007f59dc9a5ac0 R11: 0000000000000206 R12: 0000000000000000
[ +0.007141] R13: 00007ffffac992d8 R14: 0000559b9bb2f6e0 R15: 0000000000000000
[ +0.007151] </TASK>
[ +0.002204] ---[ end trace 0000000000000000 ]---
Fix this by checking if the XDP program is being loaded or unloaded.
Then, block only loading a new program while "__I40E_IN_REMOVE" is set.
Also, move testing "__I40E_IN_REMOVE" flag to the beginning of XDP_SETUP
callback to avoid unnecessary operations and checks.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
skmsg: Skip zero length skb in sk_msg_recvmsg
When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, the following kernel panic occurs:
[...]
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G OE 6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
... ...
ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
PRMD: 0000000c (PPLV0 +PIE +PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
BADV: 0000000000000040
PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160
Code: ...
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
.text @ 0x9000000003710000
.data @ 0x9000000004d70000
.bss @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
[...]
This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.
This crash is because a NULL pointer is passed to page_address() in the
sk_msg_recvmsg(). Due to the different implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on x86 platform. So this bug was hidden on x86 platform
for a while, but now it is exposed on Loongarch platform. The root cause
is that a zero length skb (skb->len == 0) was put on the queue.
This zero length skb is a TCP FIN packet, which was sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():
shutdown(p1, SHUT_WR);
In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.
And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.
To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
filelock: fix potential use-after-free in posix_lock_inode
Light Hsieh reported a KASAN UAF warning in trace_posix_lock_inode().
The request pointer had been changed earlier to point to a lock entry
that was added to the inode's list. However, before the tracepoint could
fire, another task raced in and freed that lock.
Fix this by moving the tracepoint inside the spinlock, which should
ensure that this doesn't happen.
CVSS Score
7.0
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: cyclic allocation of msg_id to avoid reuse
Reusing the msg_id after a maliciously completed reopen request may cause
a read request to remain unprocessed and result in a hung, as shown below:
t1 | t2 | t3
-------------------------------------------------
cachefiles_ondemand_select_req
cachefiles_ondemand_object_is_close(A)
cachefiles_ondemand_set_object_reopening(A)
queue_work(fscache_object_wq, &info->work)
ondemand_object_worker
cachefiles_ondemand_init_object(A)
cachefiles_ondemand_send_req(OPEN)
// get msg_id 6
wait_for_completion(&req_A->done)
cachefiles_ondemand_daemon_read
// read msg_id 6 req_A
cachefiles_ondemand_get_fd
copy_to_user
// Malicious completion msg_id 6
copen 6,-1
cachefiles_ondemand_copen
complete(&req_A->done)
// will not set the object to close
// because ondemand_id && fd is valid.
// ondemand_object_worker() is done
// but the object is still reopening.
// new open req_B
cachefiles_ondemand_init_object(B)
cachefiles_ondemand_send_req(OPEN)
// reuse msg_id 6
process_open_req
copen 6,A.size
// The expected failed copen was executed successfully
Expect copen to fail, and when it does, it closes fd, which sets the
object to close, and then close triggers reopen again. However, due to
msg_id reuse resulting in a successful copen, the anonymous fd is not
closed until the daemon exits. Therefore read requests waiting for reopen
to complete may trigger hung task.
To avoid this issue, allocate the msg_id cyclically to avoid reusing the
msg_id for a very short duration of time.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: wait for ondemand_object_worker to finish when dropping object
When queuing ondemand_object_worker() to re-open the object,
cachefiles_object is not pinned. The cachefiles_object may be freed when
the pending read request is completed intentionally and the related
erofs is umounted. If ondemand_object_worker() runs after the object is
freed, it will incur use-after-free problem as shown below.
process A processs B process C process D
cachefiles_ondemand_send_req()
// send a read req X
// wait for its completion
// close ondemand fd
cachefiles_ondemand_fd_release()
// set object as CLOSE
cachefiles_ondemand_daemon_read()
// set object as REOPENING
queue_work(fscache_wq, &info->ondemand_work)
// close /dev/cachefiles
cachefiles_daemon_release
cachefiles_flush_reqs
complete(&req->done)
// read req X is completed
// umount the erofs fs
cachefiles_put_object()
// object will be freed
cachefiles_ondemand_deinit_obj_info()
kmem_cache_free(object)
// both info and object are freed
ondemand_object_worker()
When dropping an object, it is no longer necessary to reopen the object,
so use cancel_work_sync() to cancel or wait for ondemand_object_worker()
to finish.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
vfio/pci: Init the count variable in collecting hot-reset devices
The count variable is used without initialization, it results in mistakes
in the device counting and crashes the userspace if the get hot reset info
path is triggered.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix ufshcd_abort_one racing issue
When ufshcd_abort_one is racing with the completion ISR, the completed tag
of the request's mq_hctx pointer will be set to NULL by ISR. Return
success when request is completed by ISR because ufshcd_abort_one does not
need to do anything.
The racing flow is:
Thread A
ufshcd_err_handler step 1
...
ufshcd_abort_one
ufshcd_try_to_abort_task
ufshcd_cmd_inflight(true) step 3
ufshcd_mcq_req_to_hwq
blk_mq_unique_tag
rq->mq_hctx->queue_num step 5
Thread B
ufs_mtk_mcq_intr(cq complete ISR) step 2
scsi_done
...
__blk_mq_free_request
rq->mq_hctx = NULL; step 4
Below is KE back trace.
ufshcd_try_to_abort_task: cmd at tag 41 not pending in the device.
ufshcd_try_to_abort_task: cmd at tag=41 is cleared.
Aborting tag 41 / CDB 0x28 succeeded
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194
pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14
lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40 [ufs_mediatek_mod_ise]
do_mem_abort+0x58/0x118
el1_abort+0x3c/0x5c
el1h_64_sync_handler+0x54/0x90
el1h_64_sync+0x68/0x6c
blk_mq_unique_tag+0x8/0x14
ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise]
process_one_work+0x208/0x4fc
worker_thread+0x228/0x438
kthread+0x104/0x1d4
ret_from_fork+0x10/0x20
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix ufshcd_clear_cmd racing issue
When ufshcd_clear_cmd is racing with the completion ISR, the completed tag
of the request's mq_hctx pointer will be set to NULL by the ISR. And
ufshcd_clear_cmd's call to ufshcd_mcq_req_to_hwq will get NULL pointer KE.
Return success when the request is completed by ISR because sq does not
need cleanup.
The racing flow is:
Thread A
ufshcd_err_handler step 1
ufshcd_try_to_abort_task
ufshcd_cmd_inflight(true) step 3
ufshcd_clear_cmd
...
ufshcd_mcq_req_to_hwq
blk_mq_unique_tag
rq->mq_hctx->queue_num step 5
Thread B
ufs_mtk_mcq_intr(cq complete ISR) step 2
scsi_done
...
__blk_mq_free_request
rq->mq_hctx = NULL; step 4
Below is KE back trace:
ufshcd_try_to_abort_task: cmd pending in the device. tag = 6
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194
pc : [0xffffffd589679bf8] blk_mq_unique_tag+0x8/0x14
lr : [0xffffffd5862f95b4] ufshcd_mcq_sq_cleanup+0x6c/0x1cc [ufs_mediatek_mod_ise]
Workqueue: ufs_eh_wq_0 ufshcd_err_handler [ufs_mediatek_mod_ise]
Call trace:
dump_backtrace+0xf8/0x148
show_stack+0x18/0x24
dump_stack_lvl+0x60/0x7c
dump_stack+0x18/0x3c
mrdump_common_die+0x24c/0x398 [mrdump]
ipanic_die+0x20/0x34 [mrdump]
notify_die+0x80/0xd8
die+0x94/0x2b8
__do_kernel_fault+0x264/0x298
do_page_fault+0xa4/0x4b8
do_translation_fault+0x38/0x54
do_mem_abort+0x58/0x118
el1_abort+0x3c/0x5c
el1h_64_sync_handler+0x54/0x90
el1h_64_sync+0x68/0x6c
blk_mq_unique_tag+0x8/0x14
ufshcd_clear_cmd+0x34/0x118 [ufs_mediatek_mod_ise]
ufshcd_try_to_abort_task+0x2c8/0x5b4 [ufs_mediatek_mod_ise]
ufshcd_err_handler+0xa7c/0xfa8 [ufs_mediatek_mod_ise]
process_one_work+0x208/0x4fc
worker_thread+0x228/0x438
kthread+0x104/0x1d4
ret_from_fork+0x10/0x20
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29