🚨 CVE-2024-26950
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: access device through ctx instead of peer
The previous commit fixed a bug that led to a NULL peer->device being
dereferenced. It's actually easier and faster performance-wise to
instead get the device from ctx->wg. This semantically makes more sense
too, since ctx->wg->peer_allowedips.seq is compared with
ctx->allowedips_seq, basing them both in ctx. This also acts as a
defence in depth provision against freed peers.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: access device through ctx instead of peer
The previous commit fixed a bug that led to a NULL peer->device being
dereferenced. It's actually easier and faster performance-wise to
instead get the device from ctx->wg. This semantically makes more sense
too, since ctx->wg->peer_allowedips.seq is compared with
ctx->allowedips_seq, basing them both in ctx. This also acts as a
defence in depth provision against freed peers.
🎖@cveNotify
🚨 CVE-2024-26951
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: check for dangling peer via is_dead instead of empty list
If all peers are removed via wg_peer_remove_all(), rather than setting
peer_list to empty, the peer is added to a temporary list with a head on
the stack of wg_peer_remove_all(). If a netlink dump is resumed and the
cursored peer is one that has been removed via wg_peer_remove_all(), it
will iterate from that peer and then attempt to dump freed peers.
Fix this by instead checking peer->is_dead, which was explictly created
for this purpose. Also move up the device_update_lock lockdep assertion,
since reading is_dead relies on that.
It can be reproduced by a small script like:
echo "Setting config..."
ip link add dev wg0 type wireguard
wg setconf wg0 /big-config
(
while true; do
echo "Showing config..."
wg showconf wg0 > /dev/null
done
) &
sleep 4
wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n")
Resulting in:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20
Read of size 8 at addr ffff88811956ec70 by task wg/59
CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
print_address_description.constprop.0+0x2c/0x380
print_report+0xab/0x250
kasan_report+0xba/0xf0
__lock_acquire+0x182a/0x1b20
lock_acquire+0x191/0x4b0
down_read+0x80/0x440
get_peer+0x140/0xcb0
wg_get_device_dump+0x471/0x1130
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: check for dangling peer via is_dead instead of empty list
If all peers are removed via wg_peer_remove_all(), rather than setting
peer_list to empty, the peer is added to a temporary list with a head on
the stack of wg_peer_remove_all(). If a netlink dump is resumed and the
cursored peer is one that has been removed via wg_peer_remove_all(), it
will iterate from that peer and then attempt to dump freed peers.
Fix this by instead checking peer->is_dead, which was explictly created
for this purpose. Also move up the device_update_lock lockdep assertion,
since reading is_dead relies on that.
It can be reproduced by a small script like:
echo "Setting config..."
ip link add dev wg0 type wireguard
wg setconf wg0 /big-config
(
while true; do
echo "Showing config..."
wg showconf wg0 > /dev/null
done
) &
sleep 4
wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n")
Resulting in:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20
Read of size 8 at addr ffff88811956ec70 by task wg/59
CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
print_address_description.constprop.0+0x2c/0x380
print_report+0xab/0x250
kasan_report+0xba/0xf0
__lock_acquire+0x182a/0x1b20
lock_acquire+0x191/0x4b0
down_read+0x80/0x440
get_peer+0x140/0xcb0
wg_get_device_dump+0x471/0x1130
🎖@cveNotify
🚨 CVE-2024-26952
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix potencial out-of-bounds when buffer offset is invalid
I found potencial out-of-bounds when buffer offset fields of a few requests
is invalid. This patch set the minimum value of buffer offset field to
->Buffer offset to validate buffer length.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix potencial out-of-bounds when buffer offset is invalid
I found potencial out-of-bounds when buffer offset fields of a few requests
is invalid. This patch set the minimum value of buffer offset field to
->Buffer offset to validate buffer length.
🎖@cveNotify
🚨 CVE-2024-26953
In the Linux kernel, the following vulnerability has been resolved:
net: esp: fix bad handling of pages from page_pool
When the skb is reorganized during esp_output (!esp->inline), the pages
coming from the original skb fragments are supposed to be released back
to the system through put_page. But if the skb fragment pages are
originating from a page_pool, calling put_page on them will trigger a
page_pool leak which will eventually result in a crash.
This leak can be easily observed when using CONFIG_DEBUG_VM and doing
ipsec + gre (non offloaded) forwarding:
BUG: Bad page state in process ksoftirqd/16 pfn:1451b6
page:00000000de2b8d32 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1451b6000 pfn:0x1451b6
flags: 0x200000000000000(node=0|zone=2)
page_type: 0xffffffff()
raw: 0200000000000000 dead000000000040 ffff88810d23c000 0000000000000000
raw: 00000001451b6000 0000000000000001 00000000ffffffff 0000000000000000
page dumped because: page_pool leak
Modules linked in: ip_gre gre mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core overlay zram zsmalloc fuse [last unloaded: mlx5_core]
CPU: 16 PID: 96 Comm: ksoftirqd/16 Not tainted 6.8.0-rc4+ #22
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x36/0x50
bad_page+0x70/0xf0
free_unref_page_prepare+0x27a/0x460
free_unref_page+0x38/0x120
esp_ssg_unref.isra.0+0x15f/0x200
esp_output_tail+0x66d/0x780
esp_xmit+0x2c5/0x360
validate_xmit_xfrm+0x313/0x370
? validate_xmit_skb+0x1d/0x330
validate_xmit_skb_list+0x4c/0x70
sch_direct_xmit+0x23e/0x350
__dev_queue_xmit+0x337/0xba0
? nf_hook_slow+0x3f/0xd0
ip_finish_output2+0x25e/0x580
iptunnel_xmit+0x19b/0x240
ip_tunnel_xmit+0x5fb/0xb60
ipgre_xmit+0x14d/0x280 [ip_gre]
dev_hard_start_xmit+0xc3/0x1c0
__dev_queue_xmit+0x208/0xba0
? nf_hook_slow+0x3f/0xd0
ip_finish_output2+0x1ca/0x580
ip_sublist_rcv_finish+0x32/0x40
ip_sublist_rcv+0x1b2/0x1f0
? ip_rcv_finish_core.constprop.0+0x460/0x460
ip_list_rcv+0x103/0x130
__netif_receive_skb_list_core+0x181/0x1e0
netif_receive_skb_list_internal+0x1b3/0x2c0
napi_gro_receive+0xc8/0x200
gro_cell_poll+0x52/0x90
__napi_poll+0x25/0x1a0
net_rx_action+0x28e/0x300
__do_softirq+0xc3/0x276
? sort_range+0x20/0x20
run_ksoftirqd+0x1e/0x30
smpboot_thread_fn+0xa6/0x130
kthread+0xcd/0x100
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x31/0x50
? kthread_complete_and_exit+0x20/0x20
ret_from_fork_asm+0x11/0x20
</TASK>
The suggested fix is to introduce a new wrapper (skb_page_unref) that
covers page refcounting for page_pool pages as well.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
net: esp: fix bad handling of pages from page_pool
When the skb is reorganized during esp_output (!esp->inline), the pages
coming from the original skb fragments are supposed to be released back
to the system through put_page. But if the skb fragment pages are
originating from a page_pool, calling put_page on them will trigger a
page_pool leak which will eventually result in a crash.
This leak can be easily observed when using CONFIG_DEBUG_VM and doing
ipsec + gre (non offloaded) forwarding:
BUG: Bad page state in process ksoftirqd/16 pfn:1451b6
page:00000000de2b8d32 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1451b6000 pfn:0x1451b6
flags: 0x200000000000000(node=0|zone=2)
page_type: 0xffffffff()
raw: 0200000000000000 dead000000000040 ffff88810d23c000 0000000000000000
raw: 00000001451b6000 0000000000000001 00000000ffffffff 0000000000000000
page dumped because: page_pool leak
Modules linked in: ip_gre gre mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core overlay zram zsmalloc fuse [last unloaded: mlx5_core]
CPU: 16 PID: 96 Comm: ksoftirqd/16 Not tainted 6.8.0-rc4+ #22
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x36/0x50
bad_page+0x70/0xf0
free_unref_page_prepare+0x27a/0x460
free_unref_page+0x38/0x120
esp_ssg_unref.isra.0+0x15f/0x200
esp_output_tail+0x66d/0x780
esp_xmit+0x2c5/0x360
validate_xmit_xfrm+0x313/0x370
? validate_xmit_skb+0x1d/0x330
validate_xmit_skb_list+0x4c/0x70
sch_direct_xmit+0x23e/0x350
__dev_queue_xmit+0x337/0xba0
? nf_hook_slow+0x3f/0xd0
ip_finish_output2+0x25e/0x580
iptunnel_xmit+0x19b/0x240
ip_tunnel_xmit+0x5fb/0xb60
ipgre_xmit+0x14d/0x280 [ip_gre]
dev_hard_start_xmit+0xc3/0x1c0
__dev_queue_xmit+0x208/0xba0
? nf_hook_slow+0x3f/0xd0
ip_finish_output2+0x1ca/0x580
ip_sublist_rcv_finish+0x32/0x40
ip_sublist_rcv+0x1b2/0x1f0
? ip_rcv_finish_core.constprop.0+0x460/0x460
ip_list_rcv+0x103/0x130
__netif_receive_skb_list_core+0x181/0x1e0
netif_receive_skb_list_internal+0x1b3/0x2c0
napi_gro_receive+0xc8/0x200
gro_cell_poll+0x52/0x90
__napi_poll+0x25/0x1a0
net_rx_action+0x28e/0x300
__do_softirq+0xc3/0x276
? sort_range+0x20/0x20
run_ksoftirqd+0x1e/0x30
smpboot_thread_fn+0xa6/0x130
kthread+0xcd/0x100
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x31/0x50
? kthread_complete_and_exit+0x20/0x20
ret_from_fork_asm+0x11/0x20
</TASK>
The suggested fix is to introduce a new wrapper (skb_page_unref) that
covers page refcounting for page_pool pages as well.
🎖@cveNotify
🚨 CVE-2024-26954
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()
If ->NameOffset of smb2_create_req is smaller than Buffer offset of
smb2_create_req, slab-out-of-bounds read can happen from smb2_open.
This patch set the minimum value of the name offset to the buffer offset
to validate name length of smb2_create_req().
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()
If ->NameOffset of smb2_create_req is smaller than Buffer offset of
smb2_create_req, slab-out-of-bounds read can happen from smb2_open.
This patch set the minimum value of the name offset to the buffer offset
to validate name length of smb2_create_req().
🎖@cveNotify
🚨 CVE-2024-26957
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: fix reference counting on zcrypt card objects
Tests with hot-plugging crytpo cards on KVM guests with debug
kernel build revealed an use after free for the load field of
the struct zcrypt_card. The reason was an incorrect reference
handling of the zcrypt card object which could lead to a free
of the zcrypt card object while it was still in use.
This is an example of the slab message:
kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b
kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43
kernel: kmalloc_trace+0x3f2/0x470
kernel: zcrypt_card_alloc+0x36/0x70 [zcrypt]
kernel: zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]
kernel: ap_device_probe+0x15c/0x290
kernel: really_probe+0xd2/0x468
kernel: driver_probe_device+0x40/0xf0
kernel: __device_attach_driver+0xc0/0x140
kernel: bus_for_each_drv+0x8c/0xd0
kernel: __device_attach+0x114/0x198
kernel: bus_probe_device+0xb4/0xc8
kernel: device_add+0x4d2/0x6e0
kernel: ap_scan_adapter+0x3d0/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43
kernel: kfree+0x37e/0x418
kernel: zcrypt_card_put+0x54/0x80 [zcrypt]
kernel: ap_device_remove+0x4c/0xe0
kernel: device_release_driver_internal+0x1c4/0x270
kernel: bus_remove_device+0x100/0x188
kernel: device_del+0x164/0x3c0
kernel: device_unregister+0x30/0x90
kernel: ap_scan_adapter+0xc8/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: kthread+0x150/0x168
kernel: __ret_from_fork+0x3c/0x58
kernel: ret_from_fork+0xa/0x30
kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)
kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88
kernel: Redzone 00000000885a74b0: bb bb bb bb bb bb bb bb ........
kernel: Object 00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5 kkkkkkkkkkhKkkk.
kernel: Redzone 00000000885a7518: bb bb bb bb bb bb bb bb ........
kernel: Padding 00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ
kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2
kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)
kernel: Call Trace:
kernel: [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120
kernel: [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140
kernel: [<00000000c99d53cc>] check_object+0x334/0x3f8
kernel: [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8
kernel: [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0
kernel: [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8
kernel: [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8
kernel: [<00000000c99dc8dc>] __kmalloc+0x434/0x590
kernel: [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0
kernel: [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0
kernel:
---truncated---
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: fix reference counting on zcrypt card objects
Tests with hot-plugging crytpo cards on KVM guests with debug
kernel build revealed an use after free for the load field of
the struct zcrypt_card. The reason was an incorrect reference
handling of the zcrypt card object which could lead to a free
of the zcrypt card object while it was still in use.
This is an example of the slab message:
kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b
kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43
kernel: kmalloc_trace+0x3f2/0x470
kernel: zcrypt_card_alloc+0x36/0x70 [zcrypt]
kernel: zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]
kernel: ap_device_probe+0x15c/0x290
kernel: really_probe+0xd2/0x468
kernel: driver_probe_device+0x40/0xf0
kernel: __device_attach_driver+0xc0/0x140
kernel: bus_for_each_drv+0x8c/0xd0
kernel: __device_attach+0x114/0x198
kernel: bus_probe_device+0xb4/0xc8
kernel: device_add+0x4d2/0x6e0
kernel: ap_scan_adapter+0x3d0/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43
kernel: kfree+0x37e/0x418
kernel: zcrypt_card_put+0x54/0x80 [zcrypt]
kernel: ap_device_remove+0x4c/0xe0
kernel: device_release_driver_internal+0x1c4/0x270
kernel: bus_remove_device+0x100/0x188
kernel: device_del+0x164/0x3c0
kernel: device_unregister+0x30/0x90
kernel: ap_scan_adapter+0xc8/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: kthread+0x150/0x168
kernel: __ret_from_fork+0x3c/0x58
kernel: ret_from_fork+0xa/0x30
kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)
kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88
kernel: Redzone 00000000885a74b0: bb bb bb bb bb bb bb bb ........
kernel: Object 00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5 kkkkkkkkkkhKkkk.
kernel: Redzone 00000000885a7518: bb bb bb bb bb bb bb bb ........
kernel: Padding 00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ
kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2
kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)
kernel: Call Trace:
kernel: [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120
kernel: [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140
kernel: [<00000000c99d53cc>] check_object+0x334/0x3f8
kernel: [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8
kernel: [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0
kernel: [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8
kernel: [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8
kernel: [<00000000c99dc8dc>] __kmalloc+0x434/0x590
kernel: [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0
kernel: [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0
kernel:
---truncated---
🎖@cveNotify
🚨 CVE-2024-26958
In the Linux kernel, the following vulnerability has been resolved:
nfs: fix UAF in direct writes
In production we have been hitting the following warning consistently
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0
Workqueue: nfsiod nfs_direct_write_schedule_work [nfs]
RIP: 0010:refcount_warn_saturate+0x9c/0xe0
PKRU: 55555554
Call Trace:
<TASK>
? __warn+0x9f/0x130
? refcount_warn_saturate+0x9c/0xe0
? report_bug+0xcc/0x150
? handle_bug+0x3d/0x70
? exc_invalid_op+0x16/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0x9c/0xe0
nfs_direct_write_schedule_work+0x237/0x250 [nfs]
process_one_work+0x12f/0x4a0
worker_thread+0x14e/0x3b0
? ZSTD_getCParams_internal+0x220/0x220
kthread+0xdc/0x120
? __btf_name_valid+0xa0/0xa0
ret_from_fork+0x1f/0x30
This is because we're completing the nfs_direct_request twice in a row.
The source of this is when we have our commit requests to submit, we
process them and send them off, and then in the completion path for the
commit requests we have
if (nfs_commit_end(cinfo.mds))
nfs_direct_write_complete(dreq);
However since we're submitting asynchronous requests we sometimes have
one that completes before we submit the next one, so we end up calling
complete on the nfs_direct_request twice.
The only other place we use nfs_generic_commit_list() is in
__nfs_commit_inode, which wraps this call in a
nfs_commit_begin();
nfs_commit_end();
Which is a common pattern for this style of completion handling, one
that is also repeated in the direct code with get_dreq()/put_dreq()
calls around where we process events as well as in the completion paths.
Fix this by using the same pattern for the commit requests.
Before with my 200 node rocksdb stress running this warning would pop
every 10ish minutes. With my patch the stress test has been running for
several hours without popping.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
nfs: fix UAF in direct writes
In production we have been hitting the following warning consistently
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0
Workqueue: nfsiod nfs_direct_write_schedule_work [nfs]
RIP: 0010:refcount_warn_saturate+0x9c/0xe0
PKRU: 55555554
Call Trace:
<TASK>
? __warn+0x9f/0x130
? refcount_warn_saturate+0x9c/0xe0
? report_bug+0xcc/0x150
? handle_bug+0x3d/0x70
? exc_invalid_op+0x16/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0x9c/0xe0
nfs_direct_write_schedule_work+0x237/0x250 [nfs]
process_one_work+0x12f/0x4a0
worker_thread+0x14e/0x3b0
? ZSTD_getCParams_internal+0x220/0x220
kthread+0xdc/0x120
? __btf_name_valid+0xa0/0xa0
ret_from_fork+0x1f/0x30
This is because we're completing the nfs_direct_request twice in a row.
The source of this is when we have our commit requests to submit, we
process them and send them off, and then in the completion path for the
commit requests we have
if (nfs_commit_end(cinfo.mds))
nfs_direct_write_complete(dreq);
However since we're submitting asynchronous requests we sometimes have
one that completes before we submit the next one, so we end up calling
complete on the nfs_direct_request twice.
The only other place we use nfs_generic_commit_list() is in
__nfs_commit_inode, which wraps this call in a
nfs_commit_begin();
nfs_commit_end();
Which is a common pattern for this style of completion handling, one
that is also repeated in the direct code with get_dreq()/put_dreq()
calls around where we process events as well as in the completion paths.
Fix this by using the same pattern for the commit requests.
Before with my 200 node rocksdb stress running this warning would pop
every 10ish minutes. With my patch the stress test has been running for
several hours without popping.
🎖@cveNotify
🚨 CVE-2024-26960
In the Linux kernel, the following vulnerability has been resolved:
mm: swap: fix race between free_swap_and_cache() and swapoff()
There was previously a theoretical window where swapoff() could run and
teardown a swap_info_struct while a call to free_swap_and_cache() was
running in another thread. This could cause, amongst other bad
possibilities, swap_page_trans_huge_swapped() (called by
free_swap_and_cache()) to access the freed memory for swap_map.
This is a theoretical problem and I haven't been able to provoke it from a
test case. But there has been agreement based on code review that this is
possible (see link below).
Fix it by using get_swap_device()/put_swap_device(), which will stall
swapoff(). There was an extra check in _swap_info_get() to confirm that
the swap entry was not free. This isn't present in get_swap_device()
because it doesn't make sense in general due to the race between getting
the reference and swapoff. So I've added an equivalent check directly in
free_swap_and_cache().
Details of how to provoke one possible issue (thanks to David Hildenbrand
for deriving this):
--8<-----
__swap_entry_free() might be the last user and result in
"count == SWAP_HAS_CACHE".
swapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.
So the question is: could someone reclaim the folio and turn
si->inuse_pages==0, before we completed swap_page_trans_huge_swapped().
Imagine the following: 2 MiB folio in the swapcache. Only 2 subpages are
still references by swap entries.
Process 1 still references subpage 0 via swap entry.
Process 2 still references subpage 1 via swap entry.
Process 1 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
[then, preempted in the hypervisor etc.]
Process 2 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
Process 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls
__try_to_reclaim_swap().
__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->
put_swap_folio()->free_swap_slot()->swapcache_free_entries()->
swap_entry_free()->swap_range_free()->
...
WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
What stops swapoff to succeed after process 2 reclaimed the swap cache
but before process1 finished its call to swap_page_trans_huge_swapped()?
--8<-----
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm: swap: fix race between free_swap_and_cache() and swapoff()
There was previously a theoretical window where swapoff() could run and
teardown a swap_info_struct while a call to free_swap_and_cache() was
running in another thread. This could cause, amongst other bad
possibilities, swap_page_trans_huge_swapped() (called by
free_swap_and_cache()) to access the freed memory for swap_map.
This is a theoretical problem and I haven't been able to provoke it from a
test case. But there has been agreement based on code review that this is
possible (see link below).
Fix it by using get_swap_device()/put_swap_device(), which will stall
swapoff(). There was an extra check in _swap_info_get() to confirm that
the swap entry was not free. This isn't present in get_swap_device()
because it doesn't make sense in general due to the race between getting
the reference and swapoff. So I've added an equivalent check directly in
free_swap_and_cache().
Details of how to provoke one possible issue (thanks to David Hildenbrand
for deriving this):
--8<-----
__swap_entry_free() might be the last user and result in
"count == SWAP_HAS_CACHE".
swapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.
So the question is: could someone reclaim the folio and turn
si->inuse_pages==0, before we completed swap_page_trans_huge_swapped().
Imagine the following: 2 MiB folio in the swapcache. Only 2 subpages are
still references by swap entries.
Process 1 still references subpage 0 via swap entry.
Process 2 still references subpage 1 via swap entry.
Process 1 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
[then, preempted in the hypervisor etc.]
Process 2 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
Process 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls
__try_to_reclaim_swap().
__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->
put_swap_folio()->free_swap_slot()->swapcache_free_entries()->
swap_entry_free()->swap_range_free()->
...
WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
What stops swapoff to succeed after process 2 reclaimed the swap cache
but before process1 finished its call to swap_page_trans_huge_swapped()?
--8<-----
🎖@cveNotify
🚨 CVE-2024-26961
In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix llsec key resources release in mac802154_llsec_key_del
mac802154_llsec_key_del() can free resources of a key directly without
following the RCU rules for waiting before the end of a grace period. This
may lead to use-after-free in case llsec_lookup_key() is traversing the
list of keys in parallel with a key deletion:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 4 PID: 16000 at lib/refcount.c:25 refcount_warn_saturate+0x162/0x2a0
Modules linked in:
CPU: 4 PID: 16000 Comm: wpan-ping Not tainted 6.7.0 #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x162/0x2a0
Call Trace:
<TASK>
llsec_lookup_key.isra.0+0x890/0x9e0
mac802154_llsec_encrypt+0x30c/0x9c0
ieee802154_subif_start_xmit+0x24/0x1e0
dev_hard_start_xmit+0x13e/0x690
sch_direct_xmit+0x2ae/0xbc0
__dev_queue_xmit+0x11dd/0x3c20
dgram_sendmsg+0x90b/0xd60
__sys_sendto+0x466/0x4c0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x45/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
Also, ieee802154_llsec_key_entry structures are not freed by
mac802154_llsec_key_del():
unreferenced object 0xffff8880613b6980 (size 64):
comm "iwpan", pid 2176, jiffies 4294761134 (age 60.475s)
hex dump (first 32 bytes):
78 0d 8f 18 80 88 ff ff 22 01 00 00 00 00 ad de x.......".......
00 00 00 00 00 00 00 00 03 00 cd ab 00 00 00 00 ................
backtrace:
[<ffffffff81dcfa62>] __kmem_cache_alloc_node+0x1e2/0x2d0
[<ffffffff81c43865>] kmalloc_trace+0x25/0xc0
[<ffffffff88968b09>] mac802154_llsec_key_add+0xac9/0xcf0
[<ffffffff8896e41a>] ieee802154_add_llsec_key+0x5a/0x80
[<ffffffff8892adc6>] nl802154_add_llsec_key+0x426/0x5b0
[<ffffffff86ff293e>] genl_family_rcv_msg_doit+0x1fe/0x2f0
[<ffffffff86ff46d1>] genl_rcv_msg+0x531/0x7d0
[<ffffffff86fee7a9>] netlink_rcv_skb+0x169/0x440
[<ffffffff86ff1d88>] genl_rcv+0x28/0x40
[<ffffffff86fec15c>] netlink_unicast+0x53c/0x820
[<ffffffff86fecd8b>] netlink_sendmsg+0x93b/0xe60
[<ffffffff86b91b35>] ____sys_sendmsg+0xac5/0xca0
[<ffffffff86b9c3dd>] ___sys_sendmsg+0x11d/0x1c0
[<ffffffff86b9c65a>] __sys_sendmsg+0xfa/0x1d0
[<ffffffff88eadbf5>] do_syscall_64+0x45/0xf0
[<ffffffff890000ea>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
Handle the proper resource release in the RCU callback function
mac802154_llsec_key_del_rcu().
Note that if llsec_lookup_key() finds a key, it gets a refcount via
llsec_key_get() and locally copies key id from key_entry (which is a
list element). So it's safe to call llsec_key_put() and free the list
entry after the RCU grace period elapses.
Found by Linux Verification Center (linuxtesting.org).
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix llsec key resources release in mac802154_llsec_key_del
mac802154_llsec_key_del() can free resources of a key directly without
following the RCU rules for waiting before the end of a grace period. This
may lead to use-after-free in case llsec_lookup_key() is traversing the
list of keys in parallel with a key deletion:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 4 PID: 16000 at lib/refcount.c:25 refcount_warn_saturate+0x162/0x2a0
Modules linked in:
CPU: 4 PID: 16000 Comm: wpan-ping Not tainted 6.7.0 #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x162/0x2a0
Call Trace:
<TASK>
llsec_lookup_key.isra.0+0x890/0x9e0
mac802154_llsec_encrypt+0x30c/0x9c0
ieee802154_subif_start_xmit+0x24/0x1e0
dev_hard_start_xmit+0x13e/0x690
sch_direct_xmit+0x2ae/0xbc0
__dev_queue_xmit+0x11dd/0x3c20
dgram_sendmsg+0x90b/0xd60
__sys_sendto+0x466/0x4c0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x45/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
Also, ieee802154_llsec_key_entry structures are not freed by
mac802154_llsec_key_del():
unreferenced object 0xffff8880613b6980 (size 64):
comm "iwpan", pid 2176, jiffies 4294761134 (age 60.475s)
hex dump (first 32 bytes):
78 0d 8f 18 80 88 ff ff 22 01 00 00 00 00 ad de x.......".......
00 00 00 00 00 00 00 00 03 00 cd ab 00 00 00 00 ................
backtrace:
[<ffffffff81dcfa62>] __kmem_cache_alloc_node+0x1e2/0x2d0
[<ffffffff81c43865>] kmalloc_trace+0x25/0xc0
[<ffffffff88968b09>] mac802154_llsec_key_add+0xac9/0xcf0
[<ffffffff8896e41a>] ieee802154_add_llsec_key+0x5a/0x80
[<ffffffff8892adc6>] nl802154_add_llsec_key+0x426/0x5b0
[<ffffffff86ff293e>] genl_family_rcv_msg_doit+0x1fe/0x2f0
[<ffffffff86ff46d1>] genl_rcv_msg+0x531/0x7d0
[<ffffffff86fee7a9>] netlink_rcv_skb+0x169/0x440
[<ffffffff86ff1d88>] genl_rcv+0x28/0x40
[<ffffffff86fec15c>] netlink_unicast+0x53c/0x820
[<ffffffff86fecd8b>] netlink_sendmsg+0x93b/0xe60
[<ffffffff86b91b35>] ____sys_sendmsg+0xac5/0xca0
[<ffffffff86b9c3dd>] ___sys_sendmsg+0x11d/0x1c0
[<ffffffff86b9c65a>] __sys_sendmsg+0xfa/0x1d0
[<ffffffff88eadbf5>] do_syscall_64+0x45/0xf0
[<ffffffff890000ea>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
Handle the proper resource release in the RCU callback function
mac802154_llsec_key_del_rcu().
Note that if llsec_lookup_key() finds a key, it gets a refcount via
llsec_key_get() and locally copies key id from key_entry (which is a
list element). So it's safe to call llsec_key_put() and free the list
entry after the RCU grace period elapses.
Found by Linux Verification Center (linuxtesting.org).
🎖@cveNotify
🚨 CVE-2024-26965
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-msm8974: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-msm8974: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
🚨 CVE-2024-26966
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-apq8084: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-apq8084: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
🚨 CVE-2024-26967
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: camcc-sc8280xp: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: camcc-sc8280xp: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
🚨 CVE-2024-26968
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gcc-ipq9574: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gcc-ipq9574: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
🎖@cveNotify
🚨 CVE-2024-26971
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gcc-ipq5018: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gcc-ipq5018: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
🎖@cveNotify
🚨 CVE-2024-26974
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - resolve race condition during AER recovery
During the PCI AER system's error recovery process, the kernel driver
may encounter a race condition with freeing the reset_data structure's
memory. If the device restart will take more than 10 seconds the function
scheduling that restart will exit due to a timeout, and the reset_data
structure will be freed. However, this data structure is used for
completion notification after the restart is completed, which leads
to a UAF bug.
This results in a KFENCE bug notice.
BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat]
Use-after-free read at 0x00000000bc56fddf (in kfence-#142):
adf_device_reset_worker+0x38/0xa0 [intel_qat]
process_one_work+0x173/0x340
To resolve this race condition, the memory associated to the container
of the work_struct is freed on the worker if the timeout expired,
otherwise on the function that schedules the worker.
The timeout detection can be done by checking if the caller is
still waiting for completion or not by using completion_done() function.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - resolve race condition during AER recovery
During the PCI AER system's error recovery process, the kernel driver
may encounter a race condition with freeing the reset_data structure's
memory. If the device restart will take more than 10 seconds the function
scheduling that restart will exit due to a timeout, and the reset_data
structure will be freed. However, this data structure is used for
completion notification after the restart is completed, which leads
to a UAF bug.
This results in a KFENCE bug notice.
BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat]
Use-after-free read at 0x00000000bc56fddf (in kfence-#142):
adf_device_reset_worker+0x38/0xa0 [intel_qat]
process_one_work+0x173/0x340
To resolve this race condition, the memory associated to the container
of the work_struct is freed on the worker if the timeout expired,
otherwise on the function that schedules the worker.
The timeout detection can be done by checking if the caller is
still waiting for completion or not by using completion_done() function.
🎖@cveNotify
🚨 CVE-2024-26976
In the Linux kernel, the following vulnerability has been resolved:
KVM: Always flush async #PF workqueue when vCPU is being destroyed
Always flush the per-vCPU async #PF workqueue when a vCPU is clearing its
completion queue, e.g. when a VM and all its vCPUs is being destroyed.
KVM must ensure that none of its workqueue callbacks is running when the
last reference to the KVM _module_ is put. Gifting a reference to the
associated VM prevents the workqueue callback from dereferencing freed
vCPU/VM memory, but does not prevent the KVM module from being unloaded
before the callback completes.
Drop the misguided VM refcount gifting, as calling kvm_put_kvm() from
async_pf_execute() if kvm_put_kvm() flushes the async #PF workqueue will
result in deadlock. async_pf_execute() can't return until kvm_put_kvm()
finishes, and kvm_put_kvm() can't return until async_pf_execute() finishes:
WARNING: CPU: 8 PID: 251 at virt/kvm/kvm_main.c:1435 kvm_put_kvm+0x2d/0x320 [kvm]
Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel kvm irqbypass
CPU: 8 PID: 251 Comm: kworker/8:1 Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: events async_pf_execute [kvm]
RIP: 0010:kvm_put_kvm+0x2d/0x320 [kvm]
Call Trace:
<TASK>
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
---[ end trace 0000000000000000 ]---
INFO: task kworker/8:1:251 blocked for more than 120 seconds.
Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/8:1 state:D stack:0 pid:251 ppid:2 flags:0x00004000
Workqueue: events async_pf_execute [kvm]
Call Trace:
<TASK>
__schedule+0x33f/0xa40
schedule+0x53/0xc0
schedule_timeout+0x12a/0x140
__wait_for_common+0x8d/0x1d0
__flush_work.isra.0+0x19f/0x2c0
kvm_clear_async_pf_completion_queue+0x129/0x190 [kvm]
kvm_arch_destroy_vm+0x78/0x1b0 [kvm]
kvm_put_kvm+0x1c1/0x320 [kvm]
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
If kvm_clear_async_pf_completion_queue() actually flushes the workqueue,
then there's no need to gift async_pf_execute() a reference because all
invocations of async_pf_execute() will be forced to complete before the
vCPU and its VM are destroyed/freed. And that in turn fixes the module
unloading bug as __fput() won't do module_put() on the last vCPU reference
until the vCPU has been freed, e.g. if closing the vCPU file also puts the
last reference to the KVM module.
Note that kvm_check_async_pf_completion() may also take the work item off
the completion queue and so also needs to flush the work queue, as the
work will not be seen by kvm_clear_async_pf_completion_queue(). Waiting
on the workqueue could theoretically delay a vCPU due to waiting for the
work to complete, but that's a very, very small chance, and likely a very
small delay. kvm_arch_async_page_present_queued() unconditionally makes a
new request, i.e. will effectively delay entering the guest, so the
remaining work is really just:
trace_kvm_async_pf_completed(addr, cr2_or_gpa);
__kvm_vcpu_wake_up(vcpu);
mmput(mm);
and mmput() can't drop the last reference to the page tables if the vCPU is
still alive, i.e. the vCPU won't get stuck tearing down page tables.
Add a helper to do the flushing, specifically to deal with "wakeup all"
work items, as they aren't actually work items, i.e. are never placed in a
workqueue. Trying to flush a bogus workqueue entry rightly makes
__flush_work() complain (kudos to whoever added that sanity check).
Note, commit 5f6de5cbebee ("KVM: Prevent module exit until al
---truncated---
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
KVM: Always flush async #PF workqueue when vCPU is being destroyed
Always flush the per-vCPU async #PF workqueue when a vCPU is clearing its
completion queue, e.g. when a VM and all its vCPUs is being destroyed.
KVM must ensure that none of its workqueue callbacks is running when the
last reference to the KVM _module_ is put. Gifting a reference to the
associated VM prevents the workqueue callback from dereferencing freed
vCPU/VM memory, but does not prevent the KVM module from being unloaded
before the callback completes.
Drop the misguided VM refcount gifting, as calling kvm_put_kvm() from
async_pf_execute() if kvm_put_kvm() flushes the async #PF workqueue will
result in deadlock. async_pf_execute() can't return until kvm_put_kvm()
finishes, and kvm_put_kvm() can't return until async_pf_execute() finishes:
WARNING: CPU: 8 PID: 251 at virt/kvm/kvm_main.c:1435 kvm_put_kvm+0x2d/0x320 [kvm]
Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel kvm irqbypass
CPU: 8 PID: 251 Comm: kworker/8:1 Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: events async_pf_execute [kvm]
RIP: 0010:kvm_put_kvm+0x2d/0x320 [kvm]
Call Trace:
<TASK>
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
---[ end trace 0000000000000000 ]---
INFO: task kworker/8:1:251 blocked for more than 120 seconds.
Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/8:1 state:D stack:0 pid:251 ppid:2 flags:0x00004000
Workqueue: events async_pf_execute [kvm]
Call Trace:
<TASK>
__schedule+0x33f/0xa40
schedule+0x53/0xc0
schedule_timeout+0x12a/0x140
__wait_for_common+0x8d/0x1d0
__flush_work.isra.0+0x19f/0x2c0
kvm_clear_async_pf_completion_queue+0x129/0x190 [kvm]
kvm_arch_destroy_vm+0x78/0x1b0 [kvm]
kvm_put_kvm+0x1c1/0x320 [kvm]
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
If kvm_clear_async_pf_completion_queue() actually flushes the workqueue,
then there's no need to gift async_pf_execute() a reference because all
invocations of async_pf_execute() will be forced to complete before the
vCPU and its VM are destroyed/freed. And that in turn fixes the module
unloading bug as __fput() won't do module_put() on the last vCPU reference
until the vCPU has been freed, e.g. if closing the vCPU file also puts the
last reference to the KVM module.
Note that kvm_check_async_pf_completion() may also take the work item off
the completion queue and so also needs to flush the work queue, as the
work will not be seen by kvm_clear_async_pf_completion_queue(). Waiting
on the workqueue could theoretically delay a vCPU due to waiting for the
work to complete, but that's a very, very small chance, and likely a very
small delay. kvm_arch_async_page_present_queued() unconditionally makes a
new request, i.e. will effectively delay entering the guest, so the
remaining work is really just:
trace_kvm_async_pf_completed(addr, cr2_or_gpa);
__kvm_vcpu_wake_up(vcpu);
mmput(mm);
and mmput() can't drop the last reference to the page tables if the vCPU is
still alive, i.e. the vCPU won't get stuck tearing down page tables.
Add a helper to do the flushing, specifically to deal with "wakeup all"
work items, as they aren't actually work items, i.e. are never placed in a
workqueue. Trying to flush a bogus workqueue entry rightly makes
__flush_work() complain (kudos to whoever added that sanity check).
Note, commit 5f6de5cbebee ("KVM: Prevent module exit until al
---truncated---
🎖@cveNotify
🚨 CVE-2024-26980
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-out-of-bounds in smb2_allocate_rsp_buf
If ->ProtocolId is SMB2_TRANSFORM_PROTO_NUM, smb2 request size
validation could be skipped. if request size is smaller than
sizeof(struct smb2_query_info_req), slab-out-of-bounds read can happen in
smb2_allocate_rsp_buf(). This patch allocate response buffer after
decrypting transform request. smb3_decrypt_req() will validate transform
request size and avoid slab-out-of-bound in smb2_allocate_rsp_buf().
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-out-of-bounds in smb2_allocate_rsp_buf
If ->ProtocolId is SMB2_TRANSFORM_PROTO_NUM, smb2 request size
validation could be skipped. if request size is smaller than
sizeof(struct smb2_query_info_req), slab-out-of-bounds read can happen in
smb2_allocate_rsp_buf(). This patch allocate response buffer after
decrypting transform request. smb3_decrypt_req() will validate transform
request size and avoid slab-out-of-bound in smb2_allocate_rsp_buf().
🎖@cveNotify
🚨 CVE-2024-26983
In the Linux kernel, the following vulnerability has been resolved:
bootconfig: use memblock_free_late to free xbc memory to buddy
On the time to free xbc memory in xbc_exit(), memblock may has handed
over memory to buddy allocator. So it doesn't make sense to free memory
back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs
on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86.
Following KASAN logs shows this case.
This patch fixes the xbc memory free problem by calling memblock_free()
in early xbc init error rewind path and calling memblock_free_late() in
xbc exit path to free memory to buddy allocator.
[ 9.410890] ==================================================================
[ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1
[ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5
[ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023
[ 9.460789] Call Trace:
[ 9.463518] <TASK>
[ 9.465859] dump_stack_lvl+0x53/0x70
[ 9.469949] print_report+0xce/0x610
[ 9.473944] ? __virt_addr_valid+0xf5/0x1b0
[ 9.478619] ? memblock_isolate_range+0x12d/0x260
[ 9.483877] kasan_report+0xc6/0x100
[ 9.487870] ? memblock_isolate_range+0x12d/0x260
[ 9.493125] memblock_isolate_range+0x12d/0x260
[ 9.498187] memblock_phys_free+0xb4/0x160
[ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10
[ 9.508021] ? mutex_unlock+0x7e/0xd0
[ 9.512111] ? __pfx_mutex_unlock+0x10/0x10
[ 9.516786] ? kernel_init_freeable+0x2d4/0x430
[ 9.521850] ? __pfx_kernel_init+0x10/0x10
[ 9.526426] xbc_exit+0x17/0x70
[ 9.529935] kernel_init+0x38/0x1e0
[ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30
[ 9.538601] ret_from_fork+0x2c/0x50
[ 9.542596] ? __pfx_kernel_init+0x10/0x10
[ 9.547170] ret_from_fork_asm+0x1a/0x30
[ 9.551552] </TASK>
[ 9.555649] The buggy address belongs to the physical page:
[ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30
[ 9.570821] flags: 0x200000000000000(node=0|zone=2)
[ 9.576271] page_type: 0xffffffff()
[ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000
[ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[ 9.597476] page dumped because: kasan: bad access detected
[ 9.605362] Memory state around the buggy address:
[ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.634930] ^
[ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.654675] ==================================================================
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
bootconfig: use memblock_free_late to free xbc memory to buddy
On the time to free xbc memory in xbc_exit(), memblock may has handed
over memory to buddy allocator. So it doesn't make sense to free memory
back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs
on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86.
Following KASAN logs shows this case.
This patch fixes the xbc memory free problem by calling memblock_free()
in early xbc init error rewind path and calling memblock_free_late() in
xbc exit path to free memory to buddy allocator.
[ 9.410890] ==================================================================
[ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1
[ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5
[ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023
[ 9.460789] Call Trace:
[ 9.463518] <TASK>
[ 9.465859] dump_stack_lvl+0x53/0x70
[ 9.469949] print_report+0xce/0x610
[ 9.473944] ? __virt_addr_valid+0xf5/0x1b0
[ 9.478619] ? memblock_isolate_range+0x12d/0x260
[ 9.483877] kasan_report+0xc6/0x100
[ 9.487870] ? memblock_isolate_range+0x12d/0x260
[ 9.493125] memblock_isolate_range+0x12d/0x260
[ 9.498187] memblock_phys_free+0xb4/0x160
[ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10
[ 9.508021] ? mutex_unlock+0x7e/0xd0
[ 9.512111] ? __pfx_mutex_unlock+0x10/0x10
[ 9.516786] ? kernel_init_freeable+0x2d4/0x430
[ 9.521850] ? __pfx_kernel_init+0x10/0x10
[ 9.526426] xbc_exit+0x17/0x70
[ 9.529935] kernel_init+0x38/0x1e0
[ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30
[ 9.538601] ret_from_fork+0x2c/0x50
[ 9.542596] ? __pfx_kernel_init+0x10/0x10
[ 9.547170] ret_from_fork_asm+0x1a/0x30
[ 9.551552] </TASK>
[ 9.555649] The buggy address belongs to the physical page:
[ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30
[ 9.570821] flags: 0x200000000000000(node=0|zone=2)
[ 9.576271] page_type: 0xffffffff()
[ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000
[ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
[ 9.597476] page dumped because: kasan: bad access detected
[ 9.605362] Memory state around the buggy address:
[ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.634930] ^
[ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[ 9.654675] ==================================================================
🎖@cveNotify
🚨 CVE-2024-26990
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
Check kvm_mmu_page_ad_need_write_protect() when deciding whether to
write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU
accounts for any role-specific reasons for disabling D-bit dirty logging.
Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is
being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled.
KVM always disables PML when running L2, even when L1 and L2 GPAs are in
the some domain, so failing to write-protect TDP MMU SPTEs will cause
writes made by L2 to not be reflected in the dirty log.
[sean: massage shortlog and changelog, tweak ternary op formatting]
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
Check kvm_mmu_page_ad_need_write_protect() when deciding whether to
write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU
accounts for any role-specific reasons for disabling D-bit dirty logging.
Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is
being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled.
KVM always disables PML when running L2, even when L1 and L2 GPAs are in
the some domain, so failing to write-protect TDP MMU SPTEs will cause
writes made by L2 to not be reflected in the dirty log.
[sean: massage shortlog and changelog, tweak ternary op formatting]
🎖@cveNotify
🚨 CVE-2024-26992
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/pmu: Disable support for adaptive PEBS
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.
Bug #1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.
Bug #2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record. Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.
Bug #3 is in perf. intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either. I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.
Bug #4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.
Bug #5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.
Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.
Note! This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/pmu: Disable support for adaptive PEBS
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.
Bug #1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.
Bug #2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record. Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.
Bug #3 is in perf. intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either. I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.
Bug #4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.
Bug #5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.
Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.
Note! This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity.
🎖@cveNotify
🚨 CVE-2024-26994
In the Linux kernel, the following vulnerability has been resolved:
speakup: Avoid crash on very long word
In case a console is set up really large and contains a really long word
(> 256 characters), we have to stop before the length of the word buffer.
🎖@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
speakup: Avoid crash on very long word
In case a console is set up really large and contains a really long word
(> 256 characters), we have to stop before the length of the word buffer.
🎖@cveNotify