| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()
syzbot reported the splat below without a repro.
In the splat, a single thread calling bt_accept_dequeue() freed sk
and touched it after that.
The root cause would be the racy l2cap_sock_cleanup_listen() call
added by the cited commit.
bt_accept_dequeue() is called under lock_sock() except for
l2cap_sock_release().
Two threads could see the same socket during the list iteration
in bt_accept_dequeue():
CPU1 CPU2 (close())
---- ----
sock_hold(sk) sock_hold(sk);
lock_sock(sk) <-- block close()
sock_put(sk)
bt_accept_unlink(sk)
sock_put(sk) <-- refcnt by bt_accept_enqueue()
release_sock(sk)
lock_sock(sk)
sock_put(sk)
bt_accept_unlink(sk)
sock_put(sk) <-- last refcnt
bt_accept_unlink(sk) <-- UAF
Depending on the timing, the other thread could show up in the
"Freed by task" part.
Let's call l2cap_sock_cleanup_listen() under lock_sock() in
l2cap_sock_release().
[0]:
BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115
Read of size 4 at addr ffff88803b7eb1c4 by task syz.5.3276/16995
CPU: 3 UID: 0 PID: 16995 Comm: syz.5.3276 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115
spin_lock_bh include/linux/spinlock.h:356 [inline]
release_sock+0x21/0x220 net/core/sock.c:3746
bt_accept_dequeue+0x505/0x600 net/bluetooth/af_bluetooth.c:312
l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1451
l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1425
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x3ff/0xb70 fs/file_table.c:468
task_work_run+0x14d/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2accf8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb6cb1378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000426fb RCX: 00007f2accf8ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f2acd1b7da0 R08: 0000000000000001 R09: 00000012b6cb166f
R10: 0000001b30e20000 R11: 0000000000000246 R12: 00007f2acd1b609c
R13: 00007f2acd1b6090 R14: ffffffffffffffff R15: 00007ffdb6cb1490
</TASK>
Allocated by task 5326:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4365 [inline]
__kmalloc_nopro
---truncated--- |
| MONAI (Medical Open Network for AI) is an AI toolkit for health care imaging. In versions up to and including 1.5.0, in `model_dict = torch.load(full_path, map_location=torch.device(device), weights_only=True)` in monai/bundle/scripts.py , `weights_only=True` is loaded securely. However, insecure loading methods still exist elsewhere in the project, such as when loading checkpoints. This is a common practice when users want to reduce training time and costs by loading pre-trained models downloaded from other platforms. Loading a checkpoint containing malicious content can trigger a deserialization vulnerability, leading to code execution. As of time of publication, no known fixed versions are available. |
| In the Linux kernel, the following vulnerability has been resolved:
ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog
The ptp_ocp_detach() only shuts down the watchdog timer if it is
pending. However, if the timer handler is already running, the
timer_delete_sync() is not called. This leads to race conditions
where the devlink that contains the ptp_ocp is deallocated while
the timer handler is still accessing it, resulting in use-after-free
bugs. The following details one of the race scenarios.
(thread 1) | (thread 2)
ptp_ocp_remove() |
ptp_ocp_detach() | ptp_ocp_watchdog()
if (timer_pending(&bp->watchdog))| bp = timer_container_of()
timer_delete_sync() |
|
devlink_free(devlink) //free |
| bp-> //use
Resolve this by unconditionally calling timer_delete_sync() to ensure
the timer is reliably deactivated, preventing any access after free. |
| In the Linux kernel, the following vulnerability has been resolved:
eth: mlx4: Fix IS_ERR() vs NULL check bug in mlx4_en_create_rx_ring
Replace NULL check with IS_ERR() check after calling page_pool_create()
since this function returns error pointers (ERR_PTR).
Using NULL check could lead to invalid pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
BUG: kernel NULL pointer dereference, address: 00000000000002ec
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
...
Call Trace:
<TASK>
smcr_buf_map_link+0x211/0x2a0 [smc]
__smc_buf_create+0x522/0x970 [smc]
smc_buf_create+0x3a/0x110 [smc]
smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
smc_listen_find_device+0x1dd/0x2b0 [smc]
smc_listen_work+0x30f/0x580 [smc]
process_one_work+0x18c/0x340
worker_thread+0x242/0x360
kthread+0xe7/0x220
ret_from_fork+0x13a/0x160
ret_from_fork_asm+0x1a/0x30
</TASK>
If the software RoCE device is used, ibdev->dma_device is a null pointer.
As a result, the problem occurs. Null pointer detection is added to
prevent problems. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: ti: am65-cpsw-nuss: Fix null pointer dereference for ndev
In the TX completion packet stage of TI SoCs with CPSW2G instance, which
has single external ethernet port, ndev is accessed without being
initialized if no TX packets have been processed. It results into null
pointer dereference, causing kernel to crash. Fix this by having a check
on the number of TX packets which have been processed. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: fix NULL access of tx->in_use in ice_ptp_ts_irq
The E810 device has support for a "low latency" firmware interface to
access and read the Tx timestamps. This interface does not use the standard
Tx timestamp logic, due to the latency overhead of proxying sideband
command requests over the firmware AdminQ.
The logic still makes use of the Tx timestamp tracking structure,
ice_ptp_tx, as it uses the same "ready" bitmap to track which Tx
timestamps complete.
Unfortunately, the ice_ptp_ts_irq() function does not check if the tracker
is initialized before its first access. This results in NULL dereference or
use-after-free bugs similar to the following:
[245977.278756] BUG: kernel NULL pointer dereference, address: 0000000000000000
[245977.278774] RIP: 0010:_find_first_bit+0x19/0x40
[245977.278796] Call Trace:
[245977.278809] ? ice_misc_intr+0x364/0x380 [ice]
This can occur if a Tx timestamp interrupt races with the driver reset
logic.
Fix this by only checking the in_use bitmap (and other fields) if the
tracker is marked as initialized. The reset flow will clear the init field
under lock before it tears the tracker down, thus preventing any
use-after-free or NULL access. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: fix NULL access of tx->in_use in ice_ll_ts_intr
Recent versions of the E810 firmware have support for an extra interrupt to
handle report of the "low latency" Tx timestamps coming from the
specialized low latency firmware interface. Instead of polling the
registers, software can wait until the low latency interrupt is fired.
This logic makes use of the Tx timestamp tracking structure, ice_ptp_tx, as
it uses the same "ready" bitmap to track which Tx timestamps complete.
Unfortunately, the ice_ll_ts_intr() function does not check if the
tracker is initialized before its first access. This results in NULL
dereference or use-after-free bugs similar to the issues fixed in the
ice_ptp_ts_irq() function.
Fix this by only checking the in_use bitmap (and other fields) if the
tracker is marked as initialized. The reset flow will clear the init field
under lock before it tears the tracker down, thus preventing any
use-after-free or NULL access. |
| In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix potential invalid access when MAC list is empty
list_first_entry() never returns NULL - if the list is empty, it still
returns a pointer to an invalid object, leading to potential invalid
memory access when dereferenced.
Fix this by using list_first_entry_or_null instead of list_first_entry. |
| In the Linux kernel, the following vulnerability has been resolved:
net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6
When tcp_ao_copy_all_matching() fails in tcp_v6_syn_recv_sock() it just
exits the function. This ends up causing a memory-leak:
unreferenced object 0xffff0000281a8200 (size 2496):
comm "softirq", pid 0, jiffies 4295174684
hex dump (first 32 bytes):
7f 00 00 06 7f 00 00 06 00 00 00 00 cb a8 88 13 ................
0a 00 03 61 00 00 00 00 00 00 00 00 00 00 00 00 ...a............
backtrace (crc 5ebdbe15):
kmemleak_alloc+0x44/0xe0
kmem_cache_alloc_noprof+0x248/0x470
sk_prot_alloc+0x48/0x120
sk_clone_lock+0x38/0x3b0
inet_csk_clone_lock+0x34/0x150
tcp_create_openreq_child+0x3c/0x4a8
tcp_v6_syn_recv_sock+0x1c0/0x620
tcp_check_req+0x588/0x790
tcp_v6_rcv+0x5d0/0xc18
ip6_protocol_deliver_rcu+0x2d8/0x4c0
ip6_input_finish+0x74/0x148
ip6_input+0x50/0x118
ip6_sublist_rcv+0x2fc/0x3b0
ipv6_list_rcv+0x114/0x170
__netif_receive_skb_list_core+0x16c/0x200
netif_receive_skb_list_internal+0x1f0/0x2d0
This is because in tcp_v6_syn_recv_sock (and the IPv4 counterpart), when
exiting upon error, inet_csk_prepare_forced_close() and tcp_done() need
to be called. They make sure the newsk will end up being correctly
free'd.
tcp_v4_syn_recv_sock() makes this very clear by having the put_and_exit
label that takes care of things. So, this patch here makes sure
tcp_v4_syn_recv_sock and tcp_v6_syn_recv_sock have similar
error-handling and thus fixes the leak for TCP-AO. |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: Fix NPD when refreshing an FDB entry with a nexthop object
VXLAN FDB entries can point to either a remote destination or an FDB
nexthop group. The latter is usually used in EVPN deployments where
learning is disabled.
However, when learning is enabled, an incoming packet might try to
refresh an FDB entry that points to an FDB nexthop group and therefore
does not have a remote. Such packets should be dropped, but they are
only dropped after dereferencing the non-existent remote, resulting in a
NPD [1] which can be reproduced using [2].
Fix by dropping such packets earlier. Remove the misleading comment from
first_remote_rcu().
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 361 Comm: mausezahn Not tainted 6.17.0-rc1-virtme-g9f6b606b6b37 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_snoop+0x98/0x1e0
[...]
Call Trace:
<TASK>
vxlan_encap_bypass+0x209/0x240
encap_bypass_if_local+0xb1/0x100
vxlan_xmit_one+0x1375/0x17e0
vxlan_xmit+0x6b4/0x15f0
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
packet_sendmsg+0x113a/0x1850
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
[2]
#!/bin/bash
ip address add 192.0.2.1/32 dev lo
ip address add 192.0.2.2/32 dev lo
ip nexthop add id 1 via 192.0.2.3 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 12345 localbypass
ip link add name vx1 up type vxlan id 10020 local 192.0.2.2 dstport 54321 learning
bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 192.0.2.2 port 54321 vni 10020
bridge fdb add 00:aa:bb:cc:dd:ee dev vx1 self static nhid 10
mausezahn vx0 -a 00:aa:bb:cc:dd:ee -b 00:11:22:33:44:55 -c 1 -q |
| In the Linux kernel, the following vulnerability has been resolved:
vxlan: Fix NPD in {arp,neigh}_reduce() when using nexthop objects
When the "proxy" option is enabled on a VXLAN device, the device will
suppress ARP requests and IPv6 Neighbor Solicitation messages if it is
able to reply on behalf of the remote host. That is, if a matching and
valid neighbor entry is configured on the VXLAN device whose MAC address
is not behind the "any" remote (0.0.0.0 / ::).
The code currently assumes that the FDB entry for the neighbor's MAC
address points to a valid remote destination, but this is incorrect if
the entry is associated with an FDB nexthop group. This can result in a
NPD [1][3] which can be reproduced using [2][4].
Fix by checking that the remote destination exists before dereferencing
it.
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_xmit+0xb58/0x15f0
[...]
Call Trace:
<TASK>
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
packet_sendmsg+0x113a/0x1850
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
[2]
#!/bin/bash
ip address add 192.0.2.1/32 dev lo
ip nexthop add id 1 via 192.0.2.2 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy
ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0
bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10
arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3
[3]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014
RIP: 0010:vxlan_xmit+0x803/0x1600
[...]
Call Trace:
<TASK>
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
ip6_finish_output2+0x210/0x6c0
ip6_finish_output+0x1af/0x2b0
ip6_mr_output+0x92/0x3e0
ip6_send_skb+0x30/0x90
rawv6_sendmsg+0xe6e/0x12e0
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f383422ec77
[4]
#!/bin/bash
ip address add 2001:db8:1::1/128 dev lo
ip nexthop add id 1 via 2001:db8:1::1 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy
ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0
bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10
ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: sme: cap SSID length in __cfg80211_connect_result()
If the ssid->datalen is more than IEEE80211_MAX_SSID_LEN (32) it would
lead to memory corruption so add some bounds checking. |
| In the Linux kernel, the following vulnerability has been resolved:
ax25: properly unshare skbs in ax25_kiss_rcv()
Bernard Pidoux reported a regression apparently caused by commit
c353e8983e0d ("net: introduce per netns packet chains").
skb->dev becomes NULL and we crash in __netif_receive_skb_core().
Before above commit, different kind of bugs or corruptions could happen
without a major crash.
But the root cause is that ax25_kiss_rcv() can queue/mangle input skb
without checking if this skb is shared or not.
Many thanks to Bernard Pidoux for his help, diagnosis and tests.
We had a similar issue years ago fixed with commit 7aaed57c5c28
("phonet: properly unshare skbs in phonet_rcv()"). |
| In the Linux kernel, the following vulnerability has been resolved:
ppp: fix memory leak in pad_compress_skb
If alloc_skb() fails in pad_compress_skb(), it returns NULL without
releasing the old skb. The caller does:
skb = pad_compress_skb(ppp, skb);
if (!skb)
goto drop;
drop:
kfree_skb(skb);
When pad_compress_skb() returns NULL, the reference to the old skb is
lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.
Align pad_compress_skb() semantics with realloc(): only free the old
skb if allocation and compression succeed. At the call site, use the
new_skb variable so the original skb is not lost when pad_compress_skb()
fails. |
| In the Linux kernel, the following vulnerability has been resolved:
pcmcia: Fix a NULL pointer dereference in __iodyn_find_io_region()
In __iodyn_find_io_region(), pcmcia_make_resource() is assigned to
res and used in pci_bus_alloc_resource(). There is a dereference of res
in pci_bus_alloc_resource(), which could lead to a NULL pointer
dereference on failure of pcmcia_make_resource().
Fix this bug by adding a check of res. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()
Define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure
page tables are properly synchronized when calling p*d_populate_kernel().
For 5-level paging, synchronization is performed via
pgd_populate_kernel(). In 4-level paging, pgd_populate() is a no-op, so
synchronization is instead performed at the P4D level via
p4d_populate_kernel().
This fixes intermittent boot failures on systems using 4-level paging and
a large amount of persistent memory:
BUG: unable to handle page fault for address: ffffe70000000034
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP NOPTI
RIP: 0010:__init_single_page+0x9/0x6d
Call Trace:
<TASK>
__init_zone_device_page+0x17/0x5d
memmap_init_zone_device+0x154/0x1bb
pagemap_range+0x2e0/0x40f
memremap_pages+0x10b/0x2f0
devm_memremap_pages+0x1e/0x60
dev_dax_probe+0xce/0x2ec [device_dax]
dax_bus_probe+0x6d/0xc9
[... snip ...]
</TASK>
It also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap
before sync_global_pgds() [1]:
BUG: unable to handle page fault for address: ffffeb3ff1200000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI
Tainted: [W]=WARN
RIP: 0010:vmemmap_set_pmd+0xff/0x230
<TASK>
vmemmap_populate_hugepages+0x176/0x180
vmemmap_populate+0x34/0x80
__populate_section_memmap+0x41/0x90
sparse_add_section+0x121/0x3e0
__add_pages+0xba/0x150
add_pages+0x1d/0x70
memremap_pages+0x3dc/0x810
devm_memremap_pages+0x1c/0x60
xe_devm_add+0x8b/0x100 [xe]
xe_tile_init_noalloc+0x6a/0x70 [xe]
xe_device_probe+0x48c/0x740 [xe]
[... snip ...] |
| In the Linux kernel, the following vulnerability has been resolved:
mm: move page table sync declarations to linux/pgtable.h
During our internal testing, we started observing intermittent boot
failures when the machine uses 4-level paging and has a large amount of
persistent memory:
BUG: unable to handle page fault for address: ffffe70000000034
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP NOPTI
RIP: 0010:__init_single_page+0x9/0x6d
Call Trace:
<TASK>
__init_zone_device_page+0x17/0x5d
memmap_init_zone_device+0x154/0x1bb
pagemap_range+0x2e0/0x40f
memremap_pages+0x10b/0x2f0
devm_memremap_pages+0x1e/0x60
dev_dax_probe+0xce/0x2ec [device_dax]
dax_bus_probe+0x6d/0xc9
[... snip ...]
</TASK>
It turns out that the kernel panics while initializing vmemmap (struct
page array) when the vmemmap region spans two PGD entries, because the new
PGD entry is only installed in init_mm.pgd, but not in the page tables of
other tasks.
And looking at __populate_section_memmap():
if (vmemmap_can_optimize(altmap, pgmap))
// does not sync top level page tables
r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap);
else
// sync top level page tables in x86
r = vmemmap_populate(start, end, nid, altmap);
In the normal path, vmemmap_populate() in arch/x86/mm/init_64.c
synchronizes the top level page table (See commit 9b861528a801 ("x86-64,
mem: Update all PGDs for direct mapping and vmemmap mapping changes")) so
that all tasks in the system can see the new vmemmap area.
However, when vmemmap_can_optimize() returns true, the optimized path
skips synchronization of top-level page tables. This is because
vmemmap_populate_compound_pages() is implemented in core MM code, which
does not handle synchronization of the top-level page tables. Instead,
the core MM has historically relied on each architecture to perform this
synchronization manually.
We're not the first party to encounter a crash caused by not-sync'd top
level page tables: earlier this year, Gwan-gyeong Mun attempted to address
the issue [1] [2] after hitting a kernel panic when x86 code accessed the
vmemmap area before the corresponding top-level entries were synced. At
that time, the issue was believed to be triggered only when struct page
was enlarged for debugging purposes, and the patch did not get further
updates.
It turns out that current approach of relying on each arch to handle the
page table sync manually is fragile because 1) it's easy to forget to sync
the top level page table, and 2) it's also easy to overlook that the
kernel should not access the vmemmap and direct mapping areas before the
sync.
# The solution: Make page table sync more code robust and harder to miss
To address this, Dave Hansen suggested [3] [4] introducing
{pgd,p4d}_populate_kernel() for updating kernel portion of the page tables
and allow each architecture to explicitly perform synchronization when
installing top-level entries. With this approach, we no longer need to
worry about missing the sync step, reducing the risk of future
regressions.
The new interface reuses existing ARCH_PAGE_TABLE_SYNC_MASK,
PGTBL_P*D_MODIFIED and arch_sync_kernel_mappings() facility used by
vmalloc and ioremap to synchronize page tables.
pgd_populate_kernel() looks like this:
static inline void pgd_populate_kernel(unsigned long addr, pgd_t *pgd,
p4d_t *p4d)
{
pgd_populate(&init_mm, pgd, p4d);
if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED)
arch_sync_kernel_mappings(addr, addr);
}
It is worth noting that vmalloc() and apply_to_range() carefully
synchronizes page tables by calling p*d_alloc_track() and
arch_sync_kernel_mappings(), and thus they are not affected by
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
mm: slub: avoid wake up kswapd in set_track_prepare
set_track_prepare() can incur lock recursion.
The issue is that it is called from hrtimer_start_range_ns
holding the per_cpu(hrtimer_bases)[n].lock, but when enabled
CONFIG_DEBUG_OBJECTS_TIMERS, may wake up kswapd in set_track_prepare,
and try to hold the per_cpu(hrtimer_bases)[n].lock.
Avoid deadlock caused by implicitly waking up kswapd by passing in
allocation flags, which do not contain __GFP_KSWAPD_RECLAIM in the
debug_objects_fill_pool() case. Inside stack depot they are processed by
gfp_nested_mask().
Since ___slab_alloc() has preemption disabled, we mask out
__GFP_DIRECT_RECLAIM from the flags there.
The oops looks something like:
BUG: spinlock recursion on CPU#3, swapper/3/0
lock: 0xffffff8a4bf29c80, .magic: dead4ead, .owner: swapper/3/0, .owner_cpu: 3
Hardware name: Qualcomm Technologies, Inc. Popsicle based on SM8850 (DT)
Call trace:
spin_bug+0x0
_raw_spin_lock_irqsave+0x80
hrtimer_try_to_cancel+0x94
task_contending+0x10c
enqueue_dl_entity+0x2a4
dl_server_start+0x74
enqueue_task_fair+0x568
enqueue_task+0xac
do_activate_task+0x14c
ttwu_do_activate+0xcc
try_to_wake_up+0x6c8
default_wake_function+0x20
autoremove_wake_function+0x1c
__wake_up+0xac
wakeup_kswapd+0x19c
wake_all_kswapds+0x78
__alloc_pages_slowpath+0x1ac
__alloc_pages_noprof+0x298
stack_depot_save_flags+0x6b0
stack_depot_save+0x14
set_track_prepare+0x5c
___slab_alloc+0xccc
__kmalloc_cache_noprof+0x470
__set_page_owner+0x2bc
post_alloc_hook[jt]+0x1b8
prep_new_page+0x28
get_page_from_freelist+0x1edc
__alloc_pages_noprof+0x13c
alloc_slab_page+0x244
allocate_slab+0x7c
___slab_alloc+0x8e8
kmem_cache_alloc_noprof+0x450
debug_objects_fill_pool+0x22c
debug_object_activate+0x40
enqueue_hrtimer[jt]+0xdc
hrtimer_start_range_ns+0x5f8
... |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: prevent release journal inode after journal shutdown
Before calling ocfs2_delete_osb(), ocfs2_journal_shutdown() has already
been executed in ocfs2_dismount_volume(), so osb->journal must be NULL.
Therefore, the following calltrace will inevitably fail when it reaches
jbd2_journal_release_jbd_inode().
ocfs2_dismount_volume()->
ocfs2_delete_osb()->
ocfs2_free_slot_info()->
__ocfs2_free_slot_info()->
evict()->
ocfs2_evict_inode()->
ocfs2_clear_inode()->
jbd2_journal_release_jbd_inode(osb->journal->j_journal,
Adding osb->journal checks will prevent null-ptr-deref during the above
execution path. |
