| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: properly validate chunk size in sctp_sf_ootb()
A size validation fix similar to that in Commit 50619dbf8db7 ("sctp: add
size validation when walking chunks") is also required in sctp_sf_ootb()
to address a crash reported by syzbot:
BUG: KMSAN: uninit-value in sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712
sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712
sctp_do_sm+0x181/0x93d0 net/sctp/sm_sideeffect.c:1166
sctp_endpoint_bh_rcv+0xc38/0xf90 net/sctp/endpointola.c:407
sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
sctp_rcv+0x3831/0x3b20 net/sctp/input.c:243
sctp4_rcv+0x42/0x50 net/sctp/protocol.c:1159
ip_protocol_deliver_rcu+0xb51/0x13d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x336/0x500 net/ipv4/ip_input.c:233 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: add missing size check in amdgpu_debugfs_gprwave_read()
Avoid a possible buffer overflow if size is larger than 4K.
(cherry picked from commit f5d873f5825b40d886d03bd2aede91d4cf002434) |
| In the Linux kernel, the following vulnerability has been resolved:
dm cache: fix potential out-of-bounds access on the first resume
Out-of-bounds access occurs if the fast device is expanded unexpectedly
before the first-time resume of the cache table. This happens because
expanding the fast device requires reloading the cache table for
cache_create to allocate new in-core data structures that fit the new
size, and the check in cache_preresume is not performed during the
first resume, leading to the issue.
Reproduce steps:
1. prepare component devices:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
2. load a cache table of 512 cache blocks, and deliberately expand the
fast device before resuming the cache, making the in-core data
structures inadequate.
dmsetup create cache --notable
dmsetup reload cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
dmsetup reload cdata --table "0 131072 linear /dev/sdc 8192"
dmsetup resume cdata
dmsetup resume cache
3. suspend the cache to write out the in-core dirty bitset and hint
array, leading to out-of-bounds access to the dirty bitset at offset
0x40:
dmsetup suspend cache
KASAN reports:
BUG: KASAN: vmalloc-out-of-bounds in is_dirty_callback+0x2b/0x80
Read of size 8 at addr ffffc90000085040 by task dmsetup/90
(...snip...)
The buggy address belongs to the virtual mapping at
[ffffc90000085000, ffffc90000087000) created by:
cache_ctr+0x176a/0x35f0
(...snip...)
Memory state around the buggy address:
ffffc90000084f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90000084f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90000085000: 00 00 00 00 00 00 00 00 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc90000085080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90000085100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
Fix by checking the size change on the first resume. |
| In the Linux kernel, the following vulnerability has been resolved:
filemap: Fix bounds checking in filemap_read()
If the caller supplies an iocb->ki_pos value that is close to the
filesystem upper limit, and an iterator with a count that causes us to
overflow that limit, then filemap_read() enters an infinite loop.
This behaviour was discovered when testing xfstests generic/525 with the
"localio" optimisation for loopback NFS mounts. |
| In the Linux kernel, the following vulnerability has been resolved:
signal: restore the override_rlimit logic
Prior to commit d64696905554 ("Reimplement RLIMIT_SIGPENDING on top of
ucounts") UCOUNT_RLIMIT_SIGPENDING rlimit was not enforced for a class of
signals. However now it's enforced unconditionally, even if
override_rlimit is set. This behavior change caused production issues.
For example, if the limit is reached and a process receives a SIGSEGV
signal, sigqueue_alloc fails to allocate the necessary resources for the
signal delivery, preventing the signal from being delivered with siginfo.
This prevents the process from correctly identifying the fault address and
handling the error. From the user-space perspective, applications are
unaware that the limit has been reached and that the siginfo is
effectively 'corrupted'. This can lead to unpredictable behavior and
crashes, as we observed with java applications.
Fix this by passing override_rlimit into inc_rlimit_get_ucounts() and skip
the comparison to max there if override_rlimit is set. This effectively
restores the old behavior. |
| In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: Initialization of the dangling pointer occurring in vsk->trans
During loopback communication, a dangling pointer can be created in
vsk->trans, potentially leading to a Use-After-Free condition. This
issue is resolved by initializing vsk->trans to NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix out-of-bounds write in trie_get_next_key()
trie_get_next_key() allocates a node stack with size trie->max_prefixlen,
while it writes (trie->max_prefixlen + 1) nodes to the stack when it has
full paths from the root to leaves. For example, consider a trie with
max_prefixlen is 8, and the nodes with key 0x00/0, 0x00/1, 0x00/2, ...
0x00/8 inserted. Subsequent calls to trie_get_next_key with _key with
.prefixlen = 8 make 9 nodes be written on the node stack with size 8. |
| In the Linux kernel, the following vulnerability has been resolved:
macsec: Fix use-after-free while sending the offloading packet
KASAN reports the following UAF. The metadata_dst, which is used to
store the SCI value for macsec offload, is already freed by
metadata_dst_free() in macsec_free_netdev(), while driver still use it
for sending the packet.
To fix this issue, dst_release() is used instead to release
metadata_dst. So it is not freed instantly in macsec_free_netdev() if
still referenced by skb.
BUG: KASAN: slab-use-after-free in mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]
Read of size 2 at addr ffff88813e42e038 by task kworker/7:2/714
[...]
Workqueue: mld mld_ifc_work
Call Trace:
<TASK>
dump_stack_lvl+0x51/0x60
print_report+0xc1/0x600
kasan_report+0xab/0xe0
mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]
dev_hard_start_xmit+0x120/0x530
sch_direct_xmit+0x149/0x11e0
__qdisc_run+0x3ad/0x1730
__dev_queue_xmit+0x1196/0x2ed0
vlan_dev_hard_start_xmit+0x32e/0x510 [8021q]
dev_hard_start_xmit+0x120/0x530
__dev_queue_xmit+0x14a7/0x2ed0
macsec_start_xmit+0x13e9/0x2340
dev_hard_start_xmit+0x120/0x530
__dev_queue_xmit+0x14a7/0x2ed0
ip6_finish_output2+0x923/0x1a70
ip6_finish_output+0x2d7/0x970
ip6_output+0x1ce/0x3a0
NF_HOOK.constprop.0+0x15f/0x190
mld_sendpack+0x59a/0xbd0
mld_ifc_work+0x48a/0xa80
process_one_work+0x5aa/0xe50
worker_thread+0x79c/0x1290
kthread+0x28f/0x350
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x11/0x20
</TASK>
Allocated by task 3922:
kasan_save_stack+0x20/0x40
kasan_save_track+0x10/0x30
__kasan_kmalloc+0x77/0x90
__kmalloc_noprof+0x188/0x400
metadata_dst_alloc+0x1f/0x4e0
macsec_newlink+0x914/0x1410
__rtnl_newlink+0xe08/0x15b0
rtnl_newlink+0x5f/0x90
rtnetlink_rcv_msg+0x667/0xa80
netlink_rcv_skb+0x12c/0x360
netlink_unicast+0x551/0x770
netlink_sendmsg+0x72d/0xbd0
__sock_sendmsg+0xc5/0x190
____sys_sendmsg+0x52e/0x6a0
___sys_sendmsg+0xeb/0x170
__sys_sendmsg+0xb5/0x140
do_syscall_64+0x4c/0x100
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Freed by task 4011:
kasan_save_stack+0x20/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x50
poison_slab_object+0x10c/0x190
__kasan_slab_free+0x11/0x30
kfree+0xe0/0x290
macsec_free_netdev+0x3f/0x140
netdev_run_todo+0x450/0xc70
rtnetlink_rcv_msg+0x66f/0xa80
netlink_rcv_skb+0x12c/0x360
netlink_unicast+0x551/0x770
netlink_sendmsg+0x72d/0xbd0
__sock_sendmsg+0xc5/0x190
____sys_sendmsg+0x52e/0x6a0
___sys_sendmsg+0xeb/0x170
__sys_sendmsg+0xb5/0x140
do_syscall_64+0x4c/0x100
entry_SYSCALL_64_after_hwframe+0x4b/0x53 |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()
I got a syzbot report without a repro [1] crashing in nf_send_reset6()
I think the issue is that dev->hard_header_len is zero, and we attempt
later to push an Ethernet header.
Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.
[1]
skbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900045269b0 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc
R10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140
R13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c
FS: 00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xe5/0x100 net/core/skbuff.c:2636
eth_header+0x38/0x1f0 net/ethernet/eth.c:83
dev_hard_header include/linux/netdevice.h:3208 [inline]
nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358
nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48
expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288
nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
nf_hook include/linux/netfilter.h:269 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424
__netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562
__netif_receive_skb_one_core net/core/dev.c:5666 [inline]
__netif_receive_skb+0x12f/0x650 net/core/dev.c:5781
netif_receive_skb_internal net/core/dev.c:5867 [inline]
netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926
tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550
tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007
tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053
new_sync_write fs/read_write.c:590 [inline]
vfs_write+0xa6d/0xc90 fs/read_write.c:683
ksys_write+0x183/0x2b0 fs/read_write.c:736
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbeeb7d1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48
RSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff
RDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8
RBP: 00007fdbeebf12be R08: 0000000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_ipip: Fix memory leak when changing remote IPv6 address
The device stores IPv6 addresses that are used for encapsulation in
linear memory that is managed by the driver.
Changing the remote address of an ip6gre net device never worked
properly, but since cited commit the following reproducer [1] would
result in a warning [2] and a memory leak [3]. The problem is that the
new remote address is never added by the driver to its hash table (and
therefore the device) and the old address is never removed from it.
Fix by programming the new address when the configuration of the ip6gre
net device changes and removing the old one. If the address did not
change, then the above would result in increasing the reference count of
the address and then decreasing it.
[1]
# ip link add name bla up type ip6gre local 2001:db8:1::1 remote 2001:db8:2::1 tos inherit ttl inherit
# ip link set dev bla type ip6gre remote 2001:db8:3::1
# ip link del dev bla
# devlink dev reload pci/0000:01:00.0
[2]
WARNING: CPU: 0 PID: 1682 at drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3002 mlxsw_sp_ipv6_addr_put+0x140/0x1d0
Modules linked in:
CPU: 0 UID: 0 PID: 1682 Comm: ip Not tainted 6.12.0-rc3-custom-g86b5b55bc835 #151
Hardware name: Nvidia SN5600/VMOD0013, BIOS 5.13 05/31/2023
RIP: 0010:mlxsw_sp_ipv6_addr_put+0x140/0x1d0
[...]
Call Trace:
<TASK>
mlxsw_sp_router_netdevice_event+0x55f/0x1240
notifier_call_chain+0x5a/0xd0
call_netdevice_notifiers_info+0x39/0x90
unregister_netdevice_many_notify+0x63e/0x9d0
rtnl_dellink+0x16b/0x3a0
rtnetlink_rcv_msg+0x142/0x3f0
netlink_rcv_skb+0x50/0x100
netlink_unicast+0x242/0x390
netlink_sendmsg+0x1de/0x420
____sys_sendmsg+0x2bd/0x320
___sys_sendmsg+0x9a/0xe0
__sys_sendmsg+0x7a/0xd0
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[3]
unreferenced object 0xffff898081f597a0 (size 32):
comm "ip", pid 1626, jiffies 4294719324
hex dump (first 32 bytes):
20 01 0d b8 00 02 00 00 00 00 00 00 00 00 00 01 ...............
21 49 61 83 80 89 ff ff 00 00 00 00 01 00 00 00 !Ia.............
backtrace (crc fd9be911):
[<00000000df89c55d>] __kmalloc_cache_noprof+0x1da/0x260
[<00000000ff2a1ddb>] mlxsw_sp_ipv6_addr_kvdl_index_get+0x281/0x340
[<000000009ddd445d>] mlxsw_sp_router_netdevice_event+0x47b/0x1240
[<00000000743e7757>] notifier_call_chain+0x5a/0xd0
[<000000007c7b9e13>] call_netdevice_notifiers_info+0x39/0x90
[<000000002509645d>] register_netdevice+0x5f7/0x7a0
[<00000000c2e7d2a9>] ip6gre_newlink_common.isra.0+0x65/0x130
[<0000000087cd6d8d>] ip6gre_newlink+0x72/0x120
[<000000004df7c7cc>] rtnl_newlink+0x471/0xa20
[<0000000057ed632a>] rtnetlink_rcv_msg+0x142/0x3f0
[<0000000032e0d5b5>] netlink_rcv_skb+0x50/0x100
[<00000000908bca63>] netlink_unicast+0x242/0x390
[<00000000cdbe1c87>] netlink_sendmsg+0x1de/0x420
[<0000000011db153e>] ____sys_sendmsg+0x2bd/0x320
[<000000003b6d53eb>] ___sys_sendmsg+0x9a/0xe0
[<00000000cae27c62>] __sys_sendmsg+0x7a/0xd0 |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_payload: sanitize offset and length before calling skb_checksum()
If access to offset + length is larger than the skbuff length, then
skb_checksum() triggers BUG_ON().
skb_checksum() internally subtracts the length parameter while iterating
over skbuff, BUG_ON(len) at the end of it checks that the expected
length to be included in the checksum calculation is fully consumed. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: do not pass a stopped vif to the driver in .get_txpower
Avoid potentially crashing in the driver because of uninitialized private data |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath10k: Fix memory leak in management tx
In the current logic, memory is allocated for storing the MSDU context
during management packet TX but this memory is not being freed during
management TX completion. Similar leaks are seen in the management TX
cleanup logic.
Kmemleak reports this problem as below,
unreferenced object 0xffffff80b64ed250 (size 16):
comm "kworker/u16:7", pid 148, jiffies 4294687130 (age 714.199s)
hex dump (first 16 bytes):
00 2b d8 d8 80 ff ff ff c4 74 e9 fd 07 00 00 00 .+.......t......
backtrace:
[<ffffffe6e7b245dc>] __kmem_cache_alloc_node+0x1e4/0x2d8
[<ffffffe6e7adde88>] kmalloc_trace+0x48/0x110
[<ffffffe6bbd765fc>] ath10k_wmi_tlv_op_gen_mgmt_tx_send+0xd4/0x1d8 [ath10k_core]
[<ffffffe6bbd3eed4>] ath10k_mgmt_over_wmi_tx_work+0x134/0x298 [ath10k_core]
[<ffffffe6e78d5974>] process_scheduled_works+0x1ac/0x400
[<ffffffe6e78d60b8>] worker_thread+0x208/0x328
[<ffffffe6e78dc890>] kthread+0x100/0x1c0
[<ffffffe6e78166c0>] ret_from_fork+0x10/0x20
Free the memory during completion and cleanup to fix the leak.
Protect the mgmt_pending_tx idr_remove() operation in
ath10k_wmi_tlv_op_cleanup_mgmt_tx_send() using ar->data_lock similar to
other instances.
Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.2.0-01387-QCAHLSWMTPLZ-1 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: clear wdev->cqm_config pointer on free
When we free wdev->cqm_config when unregistering, we also
need to clear out the pointer since the same wdev/netdev
may get re-registered in another network namespace, then
destroyed later, running this code again, which results in
a double-free. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet-auth: assign dh_key to NULL after kfree_sensitive
ctrl->dh_key might be used across multiple calls to nvmet_setup_dhgroup()
for the same controller. So it's better to nullify it after release on
error path in order to avoid double free later in nvmet_destroy_auth().
Found by Linux Verification Center (linuxtesting.org) with Svace. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: Fix a bug while setting up Level-2 PBL pages
Avoid memory corruption while setting up Level-2 PBL pages for the non MR
resources when num_pages > 256K.
There will be a single PDE page address (contiguous pages in the case of >
PAGE_SIZE), but, current logic assumes multiple pages, leading to invalid
memory access after 256K PBL entries in the PDE. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: Fix encoder->possible_clones
Include the encoder itself in its possible_clones bitmask.
In the past nothing validated that drivers were populating
possible_clones correctly, but that changed in commit
74d2aacbe840 ("drm: Validate encoder->possible_clones").
Looks like radeon never got the memo and is still not
following the rules 100% correctly.
This results in some warnings during driver initialization:
Bogus possible_clones: [ENCODER:46:TV-46] possible_clones=0x4 (full encoder mask=0x7)
WARNING: CPU: 0 PID: 170 at drivers/gpu/drm/drm_mode_config.c:615 drm_mode_config_validate+0x113/0x39c
...
(cherry picked from commit 3b6e7d40649c0d75572039aff9d0911864c689db) |
| In the Linux kernel, the following vulnerability has been resolved:
maple_tree: correct tree corruption on spanning store
Patch series "maple_tree: correct tree corruption on spanning store", v3.
There has been a nasty yet subtle maple tree corruption bug that appears
to have been in existence since the inception of the algorithm.
This bug seems far more likely to happen since commit f8d112a4e657
("mm/mmap: avoid zeroing vma tree in mmap_region()"), which is the point
at which reports started to be submitted concerning this bug.
We were made definitely aware of the bug thanks to the kind efforts of
Bert Karwatzki who helped enormously in my being able to track this down
and identify the cause of it.
The bug arises when an attempt is made to perform a spanning store across
two leaf nodes, where the right leaf node is the rightmost child of the
shared parent, AND the store completely consumes the right-mode node.
This results in mas_wr_spanning_store() mitakenly duplicating the new and
existing entries at the maximum pivot within the range, and thus maple
tree corruption.
The fix patch corrects this by detecting this scenario and disallowing the
mistaken duplicate copy.
The fix patch commit message goes into great detail as to how this occurs.
This series also includes a test which reliably reproduces the issue, and
asserts that the fix works correctly.
Bert has kindly tested the fix and confirmed it resolved his issues. Also
Mikhail Gavrilov kindly reported what appears to be precisely the same
bug, which this fix should also resolve.
This patch (of 2):
There has been a subtle bug present in the maple tree implementation from
its inception.
This arises from how stores are performed - when a store occurs, it will
overwrite overlapping ranges and adjust the tree as necessary to
accommodate this.
A range may always ultimately span two leaf nodes. In this instance we
walk the two leaf nodes, determine which elements are not overwritten to
the left and to the right of the start and end of the ranges respectively
and then rebalance the tree to contain these entries and the newly
inserted one.
This kind of store is dubbed a 'spanning store' and is implemented by
mas_wr_spanning_store().
In order to reach this stage, mas_store_gfp() invokes
mas_wr_preallocate(), mas_wr_store_type() and mas_wr_walk() in turn to
walk the tree and update the object (mas) to traverse to the location
where the write should be performed, determining its store type.
When a spanning store is required, this function returns false stopping at
the parent node which contains the target range, and mas_wr_store_type()
marks the mas->store_type as wr_spanning_store to denote this fact.
When we go to perform the store in mas_wr_spanning_store(), we first
determine the elements AFTER the END of the range we wish to store (that
is, to the right of the entry to be inserted) - we do this by walking to
the NEXT pivot in the tree (i.e. r_mas.last + 1), starting at the node we
have just determined contains the range over which we intend to write.
We then turn our attention to the entries to the left of the entry we are
inserting, whose state is represented by l_mas, and copy these into a 'big
node', which is a special node which contains enough slots to contain two
leaf node's worth of data.
We then copy the entry we wish to store immediately after this - the copy
and the insertion of the new entry is performed by mas_store_b_node().
After this we copy the elements to the right of the end of the range which
we are inserting, if we have not exceeded the length of the node (i.e.
r_mas.offset <= r_mas.end).
Herein lies the bug - under very specific circumstances, this logic can
break and corrupt the maple tree.
Consider the following tree:
Height
0 Root Node
/ \
pivot = 0xffff / \ pivot = ULONG_MAX
/
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
mm/swapfile: skip HugeTLB pages for unuse_vma
I got a bad pud error and lost a 1GB HugeTLB when calling swapoff. The
problem can be reproduced by the following steps:
1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory.
2. Swapout the above anonymous memory.
3. run swapoff and we will get a bad pud error in kernel message:
mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)
We can tell that pud_clear_bad is called by pud_none_or_clear_bad in
unuse_pud_range() by ftrace. And therefore the HugeTLB pages will never
be freed because we lost it from page table. We can skip HugeTLB pages
for unuse_vma to fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v4: Don't allow a VMOVP on a dying VPE
Kunkun Jiang reported that there is a small window of opportunity for
userspace to force a change of affinity for a VPE while the VPE has already
been unmapped, but the corresponding doorbell interrupt still visible in
/proc/irq/.
Plug the race by checking the value of vmapp_count, which tracks whether
the VPE is mapped ot not, and returning an error in this case.
This involves making vmapp_count common to both GICv4.1 and its v4.0
ancestor. |
