| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: netem: account for backlog updates from child qdisc
In general, 'qlen' of any classful qdisc should keep track of the
number of packets that the qdisc itself and all of its children holds.
In case of netem, 'qlen' only accounts for the packets in its internal
tfifo. When netem is used with a child qdisc, the child qdisc can use
'qdisc_tree_reduce_backlog' to inform its parent, netem, about created
or dropped SKBs. This function updates 'qlen' and the backlog statistics
of netem, but netem does not account for changes made by a child qdisc.
'qlen' then indicates the wrong number of packets in the tfifo.
If a child qdisc creates new SKBs during enqueue and informs its parent
about this, netem's 'qlen' value is increased. When netem dequeues the
newly created SKBs from the child, the 'qlen' in netem is not updated.
If 'qlen' reaches the configured sch->limit, the enqueue function stops
working, even though the tfifo is not full.
Reproduce the bug:
Ensure that the sender machine has GSO enabled. Configure netem as root
qdisc and tbf as its child on the outgoing interface of the machine
as follows:
$ tc qdisc add dev <oif> root handle 1: netem delay 100ms limit 100
$ tc qdisc add dev <oif> parent 1:0 tbf rate 50Mbit burst 1542 latency 50ms
Send bulk TCP traffic out via this interface, e.g., by running an iPerf3
client on the machine. Check the qdisc statistics:
$ tc -s qdisc show dev <oif>
Statistics after 10s of iPerf3 TCP test before the fix (note that
netem's backlog > limit, netem stopped accepting packets):
qdisc netem 1: root refcnt 2 limit 1000 delay 100ms
Sent 2767766 bytes 1848 pkt (dropped 652, overlimits 0 requeues 0)
backlog 4294528236b 1155p requeues 0
qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms
Sent 2767766 bytes 1848 pkt (dropped 327, overlimits 7601 requeues 0)
backlog 0b 0p requeues 0
Statistics after the fix:
qdisc netem 1: root refcnt 2 limit 1000 delay 100ms
Sent 37766372 bytes 24974 pkt (dropped 9, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms
Sent 37766372 bytes 24974 pkt (dropped 327, overlimits 96017 requeues 0)
backlog 0b 0p requeues 0
tbf segments the GSO SKBs (tbf_segment) and updates the netem's 'qlen'.
The interface fully stops transferring packets and "locks". In this case,
the child qdisc and tfifo are empty, but 'qlen' indicates the tfifo is at
its limit and no more packets are accepted.
This patch adds a counter for the entries in the tfifo. Netem's 'qlen' is
only decreased when a packet is returned by its dequeue function, and not
during enqueuing into the child qdisc. External updates to 'qlen' are thus
accounted for and only the behavior of the backlog statistics changes. As
in other qdiscs, 'qlen' then keeps track of how many packets are held in
netem and all of its children. As before, sch->limit remains as the
maximum number of packets in the tfifo. The same applies to netem's
backlog statistics. |
| In the Linux kernel, the following vulnerability has been resolved:
media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg
Syzbot reports [1] an uninitialized value issue found by KMSAN in
dib3000_read_reg().
Local u8 rb[2] is used in i2c_transfer() as a read buffer; in case
that call fails, the buffer may end up with some undefined values.
Since no elaborate error handling is expected in dib3000_write_reg(),
simply zero out rb buffer to mitigate the problem.
[1] Syzkaller report
dvb-usb: bulk message failed: -22 (6/0)
=====================================================
BUG: KMSAN: uninit-value in dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
dibusb_dib3000mb_frontend_attach+0x155/0x2f0 drivers/media/usb/dvb-usb/dibusb-mb.c:31
dvb_usb_adapter_frontend_init+0xed/0x9a0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:90 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline]
dvb_usb_device_init+0x25a8/0x3760 drivers/media/usb/dvb-usb/dvb-usb-init.c:310
dibusb_probe+0x46/0x250 drivers/media/usb/dvb-usb/dibusb-mb.c:110
...
Local variable rb created at:
dib3000_read_reg+0x86/0x4e0 drivers/media/dvb-frontends/dib3000mb.c:54
dib3000mb_attach+0x123/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
... |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: at_xdmac: avoid null_prt_deref in at_xdmac_prep_dma_memset
The at_xdmac_memset_create_desc may return NULL, which will lead to a
null pointer dereference. For example, the len input is error, or the
atchan->free_descs_list is empty and memory is exhausted. Therefore, add
check to avoid this. |
| In the Linux kernel, the following vulnerability has been resolved:
mtd: rawnand: fix double free in atmel_pmecc_create_user()
The "user" pointer was converted from being allocated with kzalloc() to
being allocated by devm_kzalloc(). Calling kfree(user) will lead to a
double free. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries/vas: Add close() callback in vas_vm_ops struct
The mapping VMA address is saved in VAS window struct when the
paste address is mapped. This VMA address is used during migration
to unmap the paste address if the window is active. The paste
address mapping will be removed when the window is closed or with
the munmap(). But the VMA address in the VAS window is not updated
with munmap() which is causing invalid access during migration.
The KASAN report shows:
[16386.254991] BUG: KASAN: slab-use-after-free in reconfig_close_windows+0x1a0/0x4e8
[16386.255043] Read of size 8 at addr c00000014a819670 by task drmgr/696928
[16386.255096] CPU: 29 UID: 0 PID: 696928 Comm: drmgr Kdump: loaded Tainted: G B 6.11.0-rc5-nxgzip #2
[16386.255128] Tainted: [B]=BAD_PAGE
[16386.255148] Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1110.00 (NH1110_016) hv:phyp pSeries
[16386.255181] Call Trace:
[16386.255202] [c00000016b297660] [c0000000018ad0ac] dump_stack_lvl+0x84/0xe8 (unreliable)
[16386.255246] [c00000016b297690] [c0000000006e8a90] print_report+0x19c/0x764
[16386.255285] [c00000016b297760] [c0000000006e9490] kasan_report+0x128/0x1f8
[16386.255309] [c00000016b297880] [c0000000006eb5c8] __asan_load8+0xac/0xe0
[16386.255326] [c00000016b2978a0] [c00000000013f898] reconfig_close_windows+0x1a0/0x4e8
[16386.255343] [c00000016b297990] [c000000000140e58] vas_migration_handler+0x3a4/0x3fc
[16386.255368] [c00000016b297a90] [c000000000128848] pseries_migrate_partition+0x4c/0x4c4
...
[16386.256136] Allocated by task 696554 on cpu 31 at 16377.277618s:
[16386.256149] kasan_save_stack+0x34/0x68
[16386.256163] kasan_save_track+0x34/0x80
[16386.256175] kasan_save_alloc_info+0x58/0x74
[16386.256196] __kasan_slab_alloc+0xb8/0xdc
[16386.256209] kmem_cache_alloc_noprof+0x200/0x3d0
[16386.256225] vm_area_alloc+0x44/0x150
[16386.256245] mmap_region+0x214/0x10c4
[16386.256265] do_mmap+0x5fc/0x750
[16386.256277] vm_mmap_pgoff+0x14c/0x24c
[16386.256292] ksys_mmap_pgoff+0x20c/0x348
[16386.256303] sys_mmap+0xd0/0x160
...
[16386.256350] Freed by task 0 on cpu 31 at 16386.204848s:
[16386.256363] kasan_save_stack+0x34/0x68
[16386.256374] kasan_save_track+0x34/0x80
[16386.256384] kasan_save_free_info+0x64/0x10c
[16386.256396] __kasan_slab_free+0x120/0x204
[16386.256415] kmem_cache_free+0x128/0x450
[16386.256428] vm_area_free_rcu_cb+0xa8/0xd8
[16386.256441] rcu_do_batch+0x2c8/0xcf0
[16386.256458] rcu_core+0x378/0x3c4
[16386.256473] handle_softirqs+0x20c/0x60c
[16386.256495] do_softirq_own_stack+0x6c/0x88
[16386.256509] do_softirq_own_stack+0x58/0x88
[16386.256521] __irq_exit_rcu+0x1a4/0x20c
[16386.256533] irq_exit+0x20/0x38
[16386.256544] interrupt_async_exit_prepare.constprop.0+0x18/0x2c
...
[16386.256717] Last potentially related work creation:
[16386.256729] kasan_save_stack+0x34/0x68
[16386.256741] __kasan_record_aux_stack+0xcc/0x12c
[16386.256753] __call_rcu_common.constprop.0+0x94/0xd04
[16386.256766] vm_area_free+0x28/0x3c
[16386.256778] remove_vma+0xf4/0x114
[16386.256797] do_vmi_align_munmap.constprop.0+0x684/0x870
[16386.256811] __vm_munmap+0xe0/0x1f8
[16386.256821] sys_munmap+0x54/0x6c
[16386.256830] system_call_exception+0x1a0/0x4a0
[16386.256841] system_call_vectored_common+0x15c/0x2ec
[16386.256868] The buggy address belongs to the object at c00000014a819670
which belongs to the cache vm_area_struct of size 168
[16386.256887] The buggy address is located 0 bytes inside of
freed 168-byte region [c00000014a819670, c00000014a819718)
[16386.256915] The buggy address belongs to the physical page:
[16386.256928] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14a81
[16386.256950] memcg:c0000000ba430001
[16386.256961] anon flags: 0x43ffff800000000(node=4|zone=0|lastcpupid=0x7ffff)
[16386.256975] page_type: 0xfdffffff(slab)
[16386
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Prevent bad count for tracing_cpumask_write
If a large count is provided, it will trigger a warning in bitmap_parse_user.
Also check zero for it. |
| In the Linux kernel, the following vulnerability has been resolved:
brd: defer automatic disk creation until module initialization succeeds
My colleague Wupeng found the following problems during fault injection:
BUG: unable to handle page fault for address: fffffbfff809d073
PGD 6e648067 P4D 123ec8067 PUD 123ec4067 PMD 100e38067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 5 UID: 0 PID: 755 Comm: modprobe Not tainted 6.12.0-rc3+ #17
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:__asan_load8+0x4c/0xa0
...
Call Trace:
<TASK>
blkdev_put_whole+0x41/0x70
bdev_release+0x1a3/0x250
blkdev_release+0x11/0x20
__fput+0x1d7/0x4a0
task_work_run+0xfc/0x180
syscall_exit_to_user_mode+0x1de/0x1f0
do_syscall_64+0x6b/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
loop_init() is calling loop_add() after __register_blkdev() succeeds and
is ignoring disk_add() failure from loop_add(), for loop_add() failure
is not fatal and successfully created disks are already visible to
bdev_open().
brd_init() is currently calling brd_alloc() before __register_blkdev()
succeeds and is releasing successfully created disks when brd_init()
returns an error. This can cause UAF for the latter two case:
case 1:
T1:
modprobe brd
brd_init
brd_alloc(0) // success
add_disk
disk_scan_partitions
bdev_file_open_by_dev // alloc file
fput // won't free until back to userspace
brd_alloc(1) // failed since mem alloc error inject
// error path for modprobe will release code segment
// back to userspace
__fput
blkdev_release
bdev_release
blkdev_put_whole
bdev->bd_disk->fops->release // fops is freed now, UAF!
case 2:
T1: T2:
modprobe brd
brd_init
brd_alloc(0) // success
open(/dev/ram0)
brd_alloc(1) // fail
// error path for modprobe
close(/dev/ram0)
...
/* UAF! */
bdev->bd_disk->fops->release
Fix this problem by following what loop_init() does. Besides,
reintroduce brd_devices_mutex to help serialize modifications to
brd_list. |
| In the Linux kernel, the following vulnerability has been resolved:
net: defer final 'struct net' free in netns dismantle
Ilya reported a slab-use-after-free in dst_destroy [1]
Issue is in xfrm6_net_init() and xfrm4_net_init() :
They copy xfrm[46]_dst_ops_template into net->xfrm.xfrm[46]_dst_ops.
But net structure might be freed before all the dst callbacks are
called. So when dst_destroy() calls later :
if (dst->ops->destroy)
dst->ops->destroy(dst);
dst->ops points to the old net->xfrm.xfrm[46]_dst_ops, which has been freed.
See a relevant issue fixed in :
ac888d58869b ("net: do not delay dst_entries_add() in dst_release()")
A fix is to queue the 'struct net' to be freed after one
another cleanup_net() round (and existing rcu_barrier())
[1]
BUG: KASAN: slab-use-after-free in dst_destroy (net/core/dst.c:112)
Read of size 8 at addr ffff8882137ccab0 by task swapper/37/0
Dec 03 05:46:18 kernel:
CPU: 37 UID: 0 PID: 0 Comm: swapper/37 Kdump: loaded Not tainted 6.12.0 #67
Hardware name: Red Hat KVM/RHEL, BIOS 1.16.1-1.el9 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:124)
print_address_description.constprop.0 (mm/kasan/report.c:378)
? dst_destroy (net/core/dst.c:112)
print_report (mm/kasan/report.c:489)
? dst_destroy (net/core/dst.c:112)
? kasan_addr_to_slab (mm/kasan/common.c:37)
kasan_report (mm/kasan/report.c:603)
? dst_destroy (net/core/dst.c:112)
? rcu_do_batch (kernel/rcu/tree.c:2567)
dst_destroy (net/core/dst.c:112)
rcu_do_batch (kernel/rcu/tree.c:2567)
? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491)
? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406)
rcu_core (kernel/rcu/tree.c:2825)
handle_softirqs (kernel/softirq.c:554)
__irq_exit_rcu (kernel/softirq.c:589 kernel/softirq.c:428 kernel/softirq.c:637)
irq_exit_rcu (kernel/softirq.c:651)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049)
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702)
RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:743)
Code: 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 6e ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 0f 00 2d c7 c9 27 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90
RSP: 0018:ffff888100d2fe00 EFLAGS: 00000246
RAX: 00000000001870ed RBX: 1ffff110201a5fc2 RCX: ffffffffb61a3e46
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb3d4d123
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed11c7e1835d
R10: ffff888e3f0c1aeb R11: 0000000000000000 R12: 0000000000000000
R13: ffff888100d20000 R14: dffffc0000000000 R15: 0000000000000000
? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:148)
? cpuidle_idle_call (kernel/sched/idle.c:186)
default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118)
cpuidle_idle_call (kernel/sched/idle.c:186)
? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168)
? lock_release (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5848)
? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59)
do_idle (kernel/sched/idle.c:326)
cpu_startup_entry (kernel/sched/idle.c:423 (discriminator 1))
start_secondary (arch/x86/kernel/smpboot.c:202 arch/x86/kernel/smpboot.c:282)
? __pfx_start_secondary (arch/x86/kernel/smpboot.c:232)
? soft_restart_cpu (arch/x86/kernel/head_64.S:452)
common_startup_64 (arch/x86/kernel/head_64.S:414)
</TASK>
Dec 03 05:46:18 kernel:
Allocated by task 12184:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69)
__kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345)
kmem_cache_alloc_noprof (mm/slub.c:4085 mm/slub.c:4134 mm/slub.c:4141)
copy_net_ns (net/core/net_namespace.c:421 net/core/net_namespace.c:480)
create_new_namespaces
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: fix LED ID check in led_tg_check()
Syzbot has reported the following BUG detected by KASAN:
BUG: KASAN: slab-out-of-bounds in strlen+0x58/0x70
Read of size 1 at addr ffff8881022da0c8 by task repro/5879
...
Call Trace:
<TASK>
dump_stack_lvl+0x241/0x360
? __pfx_dump_stack_lvl+0x10/0x10
? __pfx__printk+0x10/0x10
? _printk+0xd5/0x120
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x183/0x530
print_report+0x169/0x550
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x45f/0x530
? __phys_addr+0xba/0x170
? strlen+0x58/0x70
kasan_report+0x143/0x180
? strlen+0x58/0x70
strlen+0x58/0x70
kstrdup+0x20/0x80
led_tg_check+0x18b/0x3c0
xt_check_target+0x3bb/0xa40
? __pfx_xt_check_target+0x10/0x10
? stack_depot_save_flags+0x6e4/0x830
? nft_target_init+0x174/0xc30
nft_target_init+0x82d/0xc30
? __pfx_nft_target_init+0x10/0x10
? nf_tables_newrule+0x1609/0x2980
? nf_tables_newrule+0x1609/0x2980
? rcu_is_watching+0x15/0xb0
? nf_tables_newrule+0x1609/0x2980
? nf_tables_newrule+0x1609/0x2980
? __kmalloc_noprof+0x21a/0x400
nf_tables_newrule+0x1860/0x2980
? __pfx_nf_tables_newrule+0x10/0x10
? __nla_parse+0x40/0x60
nfnetlink_rcv+0x14e5/0x2ab0
? __pfx_validate_chain+0x10/0x10
? __pfx_nfnetlink_rcv+0x10/0x10
? __lock_acquire+0x1384/0x2050
? netlink_deliver_tap+0x2e/0x1b0
? __pfx_lock_release+0x10/0x10
? netlink_deliver_tap+0x2e/0x1b0
netlink_unicast+0x7f8/0x990
? __pfx_netlink_unicast+0x10/0x10
? __virt_addr_valid+0x183/0x530
? __check_object_size+0x48e/0x900
netlink_sendmsg+0x8e4/0xcb0
? __pfx_netlink_sendmsg+0x10/0x10
? aa_sock_msg_perm+0x91/0x160
? __pfx_netlink_sendmsg+0x10/0x10
__sock_sendmsg+0x223/0x270
____sys_sendmsg+0x52a/0x7e0
? __pfx_____sys_sendmsg+0x10/0x10
__sys_sendmsg+0x292/0x380
? __pfx___sys_sendmsg+0x10/0x10
? lockdep_hardirqs_on_prepare+0x43d/0x780
? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
? exc_page_fault+0x590/0x8c0
? do_syscall_64+0xb6/0x230
do_syscall_64+0xf3/0x230
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
</TASK>
Since an invalid (without '\0' byte at all) byte sequence may be passed
from userspace, add an extra check to ensure that such a sequence is
rejected as possible ID and so never passed to 'kstrdup()' and further. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: Fix use-after-free of kernel socket in cleanup_bearer().
syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]
When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().
tipc_exit_net() waits for such works to finish by checking
tipc_net(net)->wq_count. However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.
Let's move the decrement after releasing the socket in
cleanup_bearer().
[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
sk_alloc+0x438/0x608
inet_create+0x4c8/0xcb0
__sock_create+0x350/0x6b8
sock_create_kern+0x58/0x78
udp_sock_create4+0x68/0x398
udp_sock_create+0x88/0xc8
tipc_udp_enable+0x5e8/0x848
__tipc_nl_bearer_enable+0x84c/0xed8
tipc_nl_bearer_enable+0x38/0x60
genl_family_rcv_msg_doit+0x170/0x248
genl_rcv_msg+0x400/0x5b0
netlink_rcv_skb+0x1dc/0x398
genl_rcv+0x44/0x68
netlink_unicast+0x678/0x8b0
netlink_sendmsg+0x5e4/0x898
____sys_sendmsg+0x500/0x830
[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
udp_hashslot include/net/udp.h:85 [inline]
udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
__sock_release net/socket.c:658 [inline]
sock_release+0xa0/0x210 net/socket.c:686
cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
kthread+0x531/0x6b0 kernel/kthread.c:389
ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244
Uninit was created at:
slab_free_hook mm/slub.c:2269 [inline]
slab_free mm/slub.c:4580 [inline]
kmem_cache_free+0x207/0xc40 mm/slub.c:4682
net_free net/core/net_namespace.c:454 [inline]
cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
kthread+0x531/0x6b0 kernel/kthread.c:389
ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244
CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer |
| In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Add architecture specific huge_pte_clear()
When executing mm selftests run_vmtests.sh, there is such an error:
BUG: Bad page state in process uffd-unit-tests pfn:00000
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
flags: 0xffff0000002000(reserved|node=0|zone=0|lastcpupid=0xffff)
raw: 00ffff0000002000 ffffbf0000000008 ffffbf0000000008 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Modules linked in: snd_seq_dummy snd_seq snd_seq_device rfkill vfat fat
virtio_balloon efi_pstore virtio_net pstore net_failover failover fuse
nfnetlink virtio_scsi virtio_gpu virtio_dma_buf dm_multipath efivarfs
CPU: 2 UID: 0 PID: 1913 Comm: uffd-unit-tests Not tainted 6.12.0 #184
Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
Stack : 900000047c8ac000 0000000000000000 9000000000223a7c 900000047c8ac000
900000047c8af690 900000047c8af698 0000000000000000 900000047c8af7d8
900000047c8af7d0 900000047c8af7d0 900000047c8af5b0 0000000000000001
0000000000000001 900000047c8af698 10b3c7d53da40d26 0000010000000000
0000000000000022 0000000fffffffff fffffffffe000000 ffff800000000000
000000000000002f 0000800000000000 000000017a6d4000 90000000028f8940
0000000000000000 0000000000000000 90000000025aa5e0 9000000002905000
0000000000000000 90000000028f8940 ffff800000000000 0000000000000000
0000000000000000 0000000000000000 9000000000223a94 000000012001839c
00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
...
Call Trace:
[<9000000000223a94>] show_stack+0x5c/0x180
[<9000000001c3fd64>] dump_stack_lvl+0x6c/0xa0
[<900000000056aa08>] bad_page+0x1a0/0x1f0
[<9000000000574978>] free_unref_folios+0xbf0/0xd20
[<90000000004e65cc>] folios_put_refs+0x1a4/0x2b8
[<9000000000599a0c>] free_pages_and_swap_cache+0x164/0x260
[<9000000000547698>] tlb_batch_pages_flush+0xa8/0x1c0
[<9000000000547f30>] tlb_finish_mmu+0xa8/0x218
[<9000000000543cb8>] exit_mmap+0x1a0/0x360
[<9000000000247658>] __mmput+0x78/0x200
[<900000000025583c>] do_exit+0x43c/0xde8
[<9000000000256490>] do_group_exit+0x68/0x110
[<9000000000256554>] sys_exit_group+0x1c/0x20
[<9000000001c413b4>] do_syscall+0x94/0x130
[<90000000002216d8>] handle_syscall+0xb8/0x158
Disabling lock debugging due to kernel taint
BUG: non-zero pgtables_bytes on freeing mm: -16384
On LoongArch system, invalid huge pte entry should be invalid_pte_table
or a single _PAGE_HUGE bit rather than a zero value. And it should be
the same with invalid pmd entry, since pmd_none() is called by function
free_pgd_range() and pmd_none() return 0 by huge_pte_clear(). So single
_PAGE_HUGE bit is also treated as a valid pte table and free_pte_range()
will be called in free_pmd_range().
free_pmd_range()
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
free_pte_range(tlb, pmd, addr);
} while (pmd++, addr = next, addr != end);
Here invalid_pte_table is used for both invalid huge pte entry and
pmd entry. |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()
Syzbot reported that when searching for records in a directory where the
inode's i_size is corrupted and has a large value, memory access outside
the folio/page range may occur, or a use-after-free bug may be detected if
KASAN is enabled.
This is because nilfs_last_byte(), which is called by nilfs_find_entry()
and others to calculate the number of valid bytes of directory data in a
page from i_size and the page index, loses the upper 32 bits of the 64-bit
size information due to an inappropriate type of local variable to which
the i_size value is assigned.
This caused a large byte offset value due to underflow in the end address
calculation in the calling nilfs_find_entry(), resulting in memory access
that exceeds the folio/page size.
Fix this issue by changing the type of the local variable causing the bit
loss from "unsigned int" to "u64". The return value of nilfs_last_byte()
is also of type "unsigned int", but it is truncated so as not to exceed
PAGE_SIZE and no bit loss occurs, so no change is required. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix out-of-bounds access in 'dcn21_link_encoder_create'
An issue was identified in the dcn21_link_encoder_create function where
an out-of-bounds access could occur when the hpd_source index was used
to reference the link_enc_hpd_regs array. This array has a fixed size
and the index was not being checked against the array's bounds before
accessing it.
This fix adds a conditional check to ensure that the hpd_source index is
within the valid range of the link_enc_hpd_regs array. If the index is
out of bounds, the function now returns NULL to prevent undefined
behavior.
References:
[ 65.920507] ------------[ cut here ]------------
[ 65.920510] UBSAN: array-index-out-of-bounds in drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn21/dcn21_resource.c:1312:29
[ 65.920519] index 7 is out of range for type 'dcn10_link_enc_hpd_registers [5]'
[ 65.920523] CPU: 3 PID: 1178 Comm: modprobe Tainted: G OE 6.8.0-cleanershaderfeatureresetasdntipmi200nv2132 #13
[ 65.920525] Hardware name: AMD Majolica-RN/Majolica-RN, BIOS WMJ0429N_Weekly_20_04_2 04/29/2020
[ 65.920527] Call Trace:
[ 65.920529] <TASK>
[ 65.920532] dump_stack_lvl+0x48/0x70
[ 65.920541] dump_stack+0x10/0x20
[ 65.920543] __ubsan_handle_out_of_bounds+0xa2/0xe0
[ 65.920549] dcn21_link_encoder_create+0xd9/0x140 [amdgpu]
[ 65.921009] link_create+0x6d3/0xed0 [amdgpu]
[ 65.921355] create_links+0x18a/0x4e0 [amdgpu]
[ 65.921679] dc_create+0x360/0x720 [amdgpu]
[ 65.921999] ? dmi_matches+0xa0/0x220
[ 65.922004] amdgpu_dm_init+0x2b6/0x2c90 [amdgpu]
[ 65.922342] ? console_unlock+0x77/0x120
[ 65.922348] ? dev_printk_emit+0x86/0xb0
[ 65.922354] dm_hw_init+0x15/0x40 [amdgpu]
[ 65.922686] amdgpu_device_init+0x26a8/0x33a0 [amdgpu]
[ 65.922921] amdgpu_driver_load_kms+0x1b/0xa0 [amdgpu]
[ 65.923087] amdgpu_pci_probe+0x1b7/0x630 [amdgpu]
[ 65.923087] local_pci_probe+0x4b/0xb0
[ 65.923087] pci_device_probe+0xc8/0x280
[ 65.923087] really_probe+0x187/0x300
[ 65.923087] __driver_probe_device+0x85/0x130
[ 65.923087] driver_probe_device+0x24/0x110
[ 65.923087] __driver_attach+0xac/0x1d0
[ 65.923087] ? __pfx___driver_attach+0x10/0x10
[ 65.923087] bus_for_each_dev+0x7d/0xd0
[ 65.923087] driver_attach+0x1e/0x30
[ 65.923087] bus_add_driver+0xf2/0x200
[ 65.923087] driver_register+0x64/0x130
[ 65.923087] ? __pfx_amdgpu_init+0x10/0x10 [amdgpu]
[ 65.923087] __pci_register_driver+0x61/0x70
[ 65.923087] amdgpu_init+0x7d/0xff0 [amdgpu]
[ 65.923087] do_one_initcall+0x49/0x310
[ 65.923087] ? kmalloc_trace+0x136/0x360
[ 65.923087] do_init_module+0x6a/0x270
[ 65.923087] load_module+0x1fce/0x23a0
[ 65.923087] init_module_from_file+0x9c/0xe0
[ 65.923087] ? init_module_from_file+0x9c/0xe0
[ 65.923087] idempotent_init_module+0x179/0x230
[ 65.923087] __x64_sys_finit_module+0x5d/0xa0
[ 65.923087] do_syscall_64+0x76/0x120
[ 65.923087] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 65.923087] RIP: 0033:0x7f2d80f1e88d
[ 65.923087] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 b5 0f 00 f7 d8 64 89 01 48
[ 65.923087] RSP: 002b:00007ffc7bc1aa78 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 65.923087] RAX: ffffffffffffffda RBX: 0000564c9c1db130 RCX: 00007f2d80f1e88d
[ 65.923087] RDX: 0000000000000000 RSI: 0000564c9c1e5480 RDI: 000000000000000f
[ 65.923087] RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000002
[ 65.923087] R10: 000000000000000f R11: 0000000000000246 R12: 0000564c9c1e5480
[ 65.923087] R13: 0000564c9c1db260 R14: 0000000000000000 R15: 0000564c9c1e54b0
[ 65.923087] </TASK>
[ 65.923927] ---[ end trace ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: inet: do not leave a dangling sk pointer in inet_create()
sock_init_data() attaches the allocated sk object to the provided sock
object. If inet_create() fails later, the sk object is freed, but the
sock object retains the dangling pointer, which may create use-after-free
later.
Clear the sk pointer in the sock object on error. |
| In the Linux kernel, the following vulnerability has been resolved:
net: inet6: do not leave a dangling sk pointer in inet6_create()
sock_init_data() attaches the allocated sk pointer to the provided sock
object. If inet6_create() fails later, the sk object is released, but the
sock object retains the dangling sk pointer, which may cause use-after-free
later.
Clear the sock sk pointer on error. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: make sure exp active before svc_export_show
The function `e_show` was called with protection from RCU. This only
ensures that `exp` will not be freed. Therefore, the reference count for
`exp` can drop to zero, which will trigger a refcount use-after-free
warning when `exp_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `exp` remains active.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 819 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120
...
Call Trace:
<TASK>
e_show+0x20b/0x230 [nfsd]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix usage slab after free
[ +0.000021] BUG: KASAN: slab-use-after-free in drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched]
[ +0.000027] Read of size 8 at addr ffff8881b8605f88 by task amd_pci_unplug/2147
[ +0.000023] CPU: 6 PID: 2147 Comm: amd_pci_unplug Not tainted 6.10.0+ #1
[ +0.000016] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020
[ +0.000016] Call Trace:
[ +0.000008] <TASK>
[ +0.000009] dump_stack_lvl+0x76/0xa0
[ +0.000017] print_report+0xce/0x5f0
[ +0.000017] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched]
[ +0.000019] ? srso_return_thunk+0x5/0x5f
[ +0.000015] ? kasan_complete_mode_report_info+0x72/0x200
[ +0.000016] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched]
[ +0.000019] kasan_report+0xbe/0x110
[ +0.000015] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched]
[ +0.000023] __asan_report_load8_noabort+0x14/0x30
[ +0.000014] drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched]
[ +0.000020] ? srso_return_thunk+0x5/0x5f
[ +0.000013] ? __kasan_check_write+0x14/0x30
[ +0.000016] ? __pfx_drm_sched_entity_flush+0x10/0x10 [gpu_sched]
[ +0.000020] ? srso_return_thunk+0x5/0x5f
[ +0.000013] ? __kasan_check_write+0x14/0x30
[ +0.000013] ? srso_return_thunk+0x5/0x5f
[ +0.000013] ? enable_work+0x124/0x220
[ +0.000015] ? __pfx_enable_work+0x10/0x10
[ +0.000013] ? srso_return_thunk+0x5/0x5f
[ +0.000014] ? free_large_kmalloc+0x85/0xf0
[ +0.000016] drm_sched_entity_destroy+0x18/0x30 [gpu_sched]
[ +0.000020] amdgpu_vce_sw_fini+0x55/0x170 [amdgpu]
[ +0.000735] ? __kasan_check_read+0x11/0x20
[ +0.000016] vce_v4_0_sw_fini+0x80/0x110 [amdgpu]
[ +0.000726] amdgpu_device_fini_sw+0x331/0xfc0 [amdgpu]
[ +0.000679] ? mutex_unlock+0x80/0xe0
[ +0.000017] ? __pfx_amdgpu_device_fini_sw+0x10/0x10 [amdgpu]
[ +0.000662] ? srso_return_thunk+0x5/0x5f
[ +0.000014] ? __kasan_check_write+0x14/0x30
[ +0.000013] ? srso_return_thunk+0x5/0x5f
[ +0.000013] ? mutex_unlock+0x80/0xe0
[ +0.000016] amdgpu_driver_release_kms+0x16/0x80 [amdgpu]
[ +0.000663] drm_minor_release+0xc9/0x140 [drm]
[ +0.000081] drm_release+0x1fd/0x390 [drm]
[ +0.000082] __fput+0x36c/0xad0
[ +0.000018] __fput_sync+0x3c/0x50
[ +0.000014] __x64_sys_close+0x7d/0xe0
[ +0.000014] x64_sys_call+0x1bc6/0x2680
[ +0.000014] do_syscall_64+0x70/0x130
[ +0.000014] ? srso_return_thunk+0x5/0x5f
[ +0.000014] ? irqentry_exit_to_user_mode+0x60/0x190
[ +0.000015] ? srso_return_thunk+0x5/0x5f
[ +0.000014] ? irqentry_exit+0x43/0x50
[ +0.000012] ? srso_return_thunk+0x5/0x5f
[ +0.000013] ? exc_page_fault+0x7c/0x110
[ +0.000015] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ +0.000014] RIP: 0033:0x7ffff7b14f67
[ +0.000013] Code: ff e8 0d 16 02 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 73 ba f7 ff
[ +0.000026] RSP: 002b:00007fffffffe378 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
[ +0.000019] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffff7b14f67
[ +0.000014] RDX: 0000000000000000 RSI: 00007ffff7f6f47a RDI: 0000000000000003
[ +0.000014] RBP: 00007fffffffe3a0 R08: 0000555555569890 R09: 0000000000000000
[ +0.000014] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffffffe5c8
[ +0.000013] R13: 00005555555552a9 R14: 0000555555557d48 R15: 00007ffff7ffd040
[ +0.000020] </TASK>
[ +0.000016] Allocated by task 383 on cpu 7 at 26.880319s:
[ +0.000014] kasan_save_stack+0x28/0x60
[ +0.000008] kasan_save_track+0x18/0x70
[ +0.000007] kasan_save_alloc_info+0x38/0x60
[ +0.000007] __kasan_kmalloc+0xc1/0xd0
[ +0.000007] kmalloc_trace_noprof+0x180/0x380
[ +0.000007] drm_sched_init+0x411/0xec0 [gpu_sched]
[ +0.000012] amdgpu_device_init+0x695f/0xa610 [amdgpu]
[ +0.000658] amdgpu_driver_load_kms+0x1a/0x120 [amdgpu]
[ +0.000662] amdgpu_pci_p
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
hfsplus: don't query the device logical block size multiple times
Devices block sizes may change. One of these cases is a loop device by
using ioctl LOOP_SET_BLOCK_SIZE.
While this may cause other issues like IO being rejected, in the case of
hfsplus, it will allocate a block by using that size and potentially write
out-of-bounds when hfsplus_read_wrapper calls hfsplus_submit_bio and the
latter function reads a different io_size.
Using a new min_io_size initally set to sb_min_blocksize works for the
purposes of the original fix, since it will be set to the max between
HFSPLUS_SECTOR_SIZE and the first seen logical block size. We still use the
max between HFSPLUS_SECTOR_SIZE and min_io_size in case the latter is not
initialized.
Tested by mounting an hfsplus filesystem with loop block sizes 512, 1024
and 4096.
The produced KASAN report before the fix looks like this:
[ 419.944641] ==================================================================
[ 419.945655] BUG: KASAN: slab-use-after-free in hfsplus_read_wrapper+0x659/0xa0a
[ 419.946703] Read of size 2 at addr ffff88800721fc00 by task repro/10678
[ 419.947612]
[ 419.947846] CPU: 0 UID: 0 PID: 10678 Comm: repro Not tainted 6.12.0-rc5-00008-gdf56e0f2f3ca #84
[ 419.949007] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
[ 419.950035] Call Trace:
[ 419.950384] <TASK>
[ 419.950676] dump_stack_lvl+0x57/0x78
[ 419.951212] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.951830] print_report+0x14c/0x49e
[ 419.952361] ? __virt_addr_valid+0x267/0x278
[ 419.952979] ? kmem_cache_debug_flags+0xc/0x1d
[ 419.953561] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.954231] kasan_report+0x89/0xb0
[ 419.954748] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.955367] hfsplus_read_wrapper+0x659/0xa0a
[ 419.955948] ? __pfx_hfsplus_read_wrapper+0x10/0x10
[ 419.956618] ? do_raw_spin_unlock+0x59/0x1a9
[ 419.957214] ? _raw_spin_unlock+0x1a/0x2e
[ 419.957772] hfsplus_fill_super+0x348/0x1590
[ 419.958355] ? hlock_class+0x4c/0x109
[ 419.958867] ? __pfx_hfsplus_fill_super+0x10/0x10
[ 419.959499] ? __pfx_string+0x10/0x10
[ 419.960006] ? lock_acquire+0x3e2/0x454
[ 419.960532] ? bdev_name.constprop.0+0xce/0x243
[ 419.961129] ? __pfx_bdev_name.constprop.0+0x10/0x10
[ 419.961799] ? pointer+0x3f0/0x62f
[ 419.962277] ? __pfx_pointer+0x10/0x10
[ 419.962761] ? vsnprintf+0x6c4/0xfba
[ 419.963178] ? __pfx_vsnprintf+0x10/0x10
[ 419.963621] ? setup_bdev_super+0x376/0x3b3
[ 419.964029] ? snprintf+0x9d/0xd2
[ 419.964344] ? __pfx_snprintf+0x10/0x10
[ 419.964675] ? lock_acquired+0x45c/0x5e9
[ 419.965016] ? set_blocksize+0x139/0x1c1
[ 419.965381] ? sb_set_blocksize+0x6d/0xae
[ 419.965742] ? __pfx_hfsplus_fill_super+0x10/0x10
[ 419.966179] mount_bdev+0x12f/0x1bf
[ 419.966512] ? __pfx_mount_bdev+0x10/0x10
[ 419.966886] ? vfs_parse_fs_string+0xce/0x111
[ 419.967293] ? __pfx_vfs_parse_fs_string+0x10/0x10
[ 419.967702] ? __pfx_hfsplus_mount+0x10/0x10
[ 419.968073] legacy_get_tree+0x104/0x178
[ 419.968414] vfs_get_tree+0x86/0x296
[ 419.968751] path_mount+0xba3/0xd0b
[ 419.969157] ? __pfx_path_mount+0x10/0x10
[ 419.969594] ? kmem_cache_free+0x1e2/0x260
[ 419.970311] do_mount+0x99/0xe0
[ 419.970630] ? __pfx_do_mount+0x10/0x10
[ 419.971008] __do_sys_mount+0x199/0x1c9
[ 419.971397] do_syscall_64+0xd0/0x135
[ 419.971761] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 419.972233] RIP: 0033:0x7c3cb812972e
[ 419.972564] Code: 48 8b 0d f5 46 0d 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 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c2 46 0d 00 f7 d8 64 89 01 48
[ 419.974371] RSP: 002b:00007ffe30632548 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
[ 419.975048] RAX: ffffffffffffffda RBX: 00007ffe306328d8 RCX: 00007c3cb812972e
[ 419.975701] RDX: 0000000020000000 RSI: 0000000020000c80 RDI:
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/modes: Avoid divide by zero harder in drm_mode_vrefresh()
drm_mode_vrefresh() is trying to avoid divide by zero
by checking whether htotal or vtotal are zero. But we may
still end up with a div-by-zero of vtotal*htotal*... |
| In the Linux kernel, the following vulnerability has been resolved:
Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet
If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is
fully initialized, we can hit the panic below:
hv_utils: Registering HyperV Utility Driver
hv_vmbus: registering driver hv_utils
...
BUG: kernel NULL pointer dereference, address: 0000000000000000
CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1
RIP: 0010:hv_pkt_iter_first+0x12/0xd0
Call Trace:
...
vmbus_recvpacket
hv_kvp_onchannelcallback
vmbus_on_event
tasklet_action_common
tasklet_action
handle_softirqs
irq_exit_rcu
sysvec_hyperv_stimer0
</IRQ>
<TASK>
asm_sysvec_hyperv_stimer0
...
kvp_register_done
hvt_op_read
vfs_read
ksys_read
__x64_sys_read
This can happen because the KVP/VSS channel callback can be invoked
even before the channel is fully opened:
1) as soon as hv_kvp_init() -> hvutil_transport_init() creates
/dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and
register itself to the driver by writing a message KVP_OP_REGISTER1 to the
file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and
reading the file for the driver's response, which is handled by
hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done().
2) the problem with kvp_register_done() is that it can cause the
channel callback to be called even before the channel is fully opened,
and when the channel callback is starting to run, util_probe()->
vmbus_open() may have not initialized the ringbuffer yet, so the
callback can hit the panic of NULL pointer dereference.
To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in
__vmbus_open(), just before the first hv_ringbuffer_init(), and then we
unload and reload the driver hv_utils, and run the daemon manually within
the 10 seconds.
Fix the panic by reordering the steps in util_probe() so the char dev
entry used by the KVP or VSS daemon is not created until after
vmbus_open() has completed. This reordering prevents the race condition
from happening. |
