| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: ti: edma: Fix memory allocation size for queue_priority_map
Fix a critical memory allocation bug in edma_setup_from_hw() where
queue_priority_map was allocated with insufficient memory. The code
declared queue_priority_map as s8 (*)[2] (pointer to array of 2 s8),
but allocated memory using sizeof(s8) instead of the correct size.
This caused out-of-bounds memory writes when accessing:
queue_priority_map[i][0] = i;
queue_priority_map[i][1] = i;
The bug manifested as kernel crashes with "Oops - undefined instruction"
on ARM platforms (BeagleBoard-X15) during EDMA driver probe, as the
memory corruption triggered kernel hardening features on Clang.
Change the allocation to use sizeof(*queue_priority_map) which
automatically gets the correct size for the 2D array structure. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: allow SC_STATUS_FREEABLE when searching via nfs4_lookup_stateid()
The pynfs DELEG8 test fails when run against nfsd. It acquires a
delegation and then lets the lease time out. It then tries to use the
deleg stateid and expects to see NFS4ERR_DELEG_REVOKED, but it gets
bad NFS4ERR_BAD_STATEID instead.
When a delegation is revoked, it's initially marked with
SC_STATUS_REVOKED, or SC_STATUS_ADMIN_REVOKED and later, it's marked
with the SC_STATUS_FREEABLE flag, which denotes that it is waiting for
s FREE_STATEID call.
nfs4_lookup_stateid() accepts a statusmask that includes the status
flags that a found stateid is allowed to have. Currently, that mask
never includes SC_STATUS_FREEABLE, which means that revoked delegations
are (almost) never found.
Add SC_STATUS_FREEABLE to the always-allowed status flags, and remove it
from nfsd4_delegreturn() since it's now always implied. |
| In the Linux kernel, the following vulnerability has been resolved:
smb3: fix for slab out of bounds on mount to ksmbd
With KASAN enabled, it is possible to get a slab out of bounds
during mount to ksmbd due to missing check in parse_server_interfaces()
(see below):
BUG: KASAN: slab-out-of-bounds in
parse_server_interfaces+0x14ee/0x1880 [cifs]
Read of size 4 at addr ffff8881433dba98 by task mount/9827
CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G
OE 6.16.0-rc2-kasan #2 PREEMPT(voluntary)
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. Precision Tower 3620/0MWYPT,
BIOS 2.13.1 06/14/2019
Call Trace:
<TASK>
dump_stack_lvl+0x9f/0xf0
print_report+0xd1/0x670
__virt_addr_valid+0x22c/0x430
? parse_server_interfaces+0x14ee/0x1880 [cifs]
? kasan_complete_mode_report_info+0x2a/0x1f0
? parse_server_interfaces+0x14ee/0x1880 [cifs]
kasan_report+0xd6/0x110
parse_server_interfaces+0x14ee/0x1880 [cifs]
__asan_report_load_n_noabort+0x13/0x20
parse_server_interfaces+0x14ee/0x1880 [cifs]
? __pfx_parse_server_interfaces+0x10/0x10 [cifs]
? trace_hardirqs_on+0x51/0x60
SMB3_request_interfaces+0x1ad/0x3f0 [cifs]
? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs]
? SMB2_tcon+0x23c/0x15d0 [cifs]
smb3_qfs_tcon+0x173/0x2b0 [cifs]
? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
? cifs_get_tcon+0x105d/0x2120 [cifs]
? do_raw_spin_unlock+0x5d/0x200
? cifs_get_tcon+0x105d/0x2120 [cifs]
? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
cifs_mount_get_tcon+0x369/0xb90 [cifs]
? dfs_cache_find+0xe7/0x150 [cifs]
dfs_mount_share+0x985/0x2970 [cifs]
? check_path.constprop.0+0x28/0x50
? save_trace+0x54/0x370
? __pfx_dfs_mount_share+0x10/0x10 [cifs]
? __lock_acquire+0xb82/0x2ba0
? __kasan_check_write+0x18/0x20
cifs_mount+0xbc/0x9e0 [cifs]
? __pfx_cifs_mount+0x10/0x10 [cifs]
? do_raw_spin_unlock+0x5d/0x200
? cifs_setup_cifs_sb+0x29d/0x810 [cifs]
cifs_smb3_do_mount+0x263/0x1990 [cifs] |
| In the Linux kernel, the following vulnerability has been resolved:
media: venus: Fix OOB read due to missing payload bound check
Currently, The event_seq_changed() handler processes a variable number
of properties sent by the firmware. The number of properties is indicated
by the firmware and used to iterate over the payload. However, the
payload size is not being validated against the actual message length.
This can lead to out-of-bounds memory access if the firmware provides a
property count that exceeds the data available in the payload. Such a
condition can result in kernel crashes or potential information leaks if
memory beyond the buffer is accessed.
Fix this by properly validating the remaining size of the payload before
each property access and updating bounds accordingly as properties are
parsed.
This ensures that property parsing is safely bounded within the received
message buffer and protects against malformed or malicious firmware
behavior. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: reject duplicate device on updates
A chain/flowtable update with duplicated devices in the same batch is
possible. Unfortunately, netdev event path only removes the first
device that is found, leaving unregistered the hook of the duplicated
device.
Check if a duplicated device exists in the transaction batch, bail out
with EEXIST in such case.
WARNING is hit when unregistering the hook:
[49042.221275] WARNING: CPU: 4 PID: 8425 at net/netfilter/core.c:340 nf_hook_entry_head+0xaa/0x150
[49042.221375] CPU: 4 UID: 0 PID: 8425 Comm: nft Tainted: G S 6.16.0+ #170 PREEMPT(full)
[...]
[49042.221382] RIP: 0010:nf_hook_entry_head+0xaa/0x150 |
| In the Linux kernel, the following vulnerability has been resolved:
gfs2: No more self recovery
When a node withdraws and it turns out that it is the only node that has
the filesystem mounted, gfs2 currently tries to replay the local journal
to bring the filesystem back into a consistent state. Not only is that
a very bad idea, it has also never worked because gfs2_recover_func()
will refuse to do anything during a withdraw.
However, before even getting to this point, gfs2_recover_func()
dereferences sdp->sd_jdesc->jd_inode. This was a use-after-free before
commit 04133b607a78 ("gfs2: Prevent double iput for journal on error")
and is a NULL pointer dereference since then.
Simply get rid of self recovery to fix that. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_devcd_dump: fix out-of-bounds via dev_coredumpv
Currently both dev_coredumpv and skb_put_data in hci_devcd_dump use
hdev->dump.head. However, dev_coredumpv can free the buffer. From
dev_coredumpm_timeout documentation, which is used by dev_coredumpv:
> Creates a new device coredump for the given device. If a previous one hasn't
> been read yet, the new coredump is discarded. The data lifetime is determined
> by the device coredump framework and when it is no longer needed the @free
> function will be called to free the data.
If the data has not been read by the userspace yet, dev_coredumpv will
discard new buffer, freeing hdev->dump.head. This leads to
vmalloc-out-of-bounds error when skb_put_data tries to access
hdev->dump.head.
A crash report from syzbot illustrates this:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in skb_put_data
include/linux/skbuff.h:2752 [inline]
BUG: KASAN: vmalloc-out-of-bounds in hci_devcd_dump+0x142/0x240
net/bluetooth/coredump.c:258
Read of size 140 at addr ffffc90004ed5000 by task kworker/u9:2/5844
CPU: 1 UID: 0 PID: 5844 Comm: kworker/u9:2 Not tainted
6.14.0-syzkaller-10892-g4e82c87058f4 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 02/12/2025
Workqueue: hci0 hci_devcd_timeout
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:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
__asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105
skb_put_data include/linux/skbuff.h:2752 [inline]
hci_devcd_dump+0x142/0x240 net/bluetooth/coredump.c:258
hci_devcd_timeout+0xb5/0x2e0 net/bluetooth/coredump.c:413
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
The buggy address ffffc90004ed5000 belongs to a vmalloc virtual mapping
Memory state around the buggy address:
ffffc90004ed4f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90004ed4f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90004ed5000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc90004ed5080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90004ed5100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================
To avoid this issue, reorder dev_coredumpv to be called after
skb_put_data that does not free the data. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid panic in f2fs_evict_inode
As syzbot [1] reported as below:
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe17473450
R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520
</TASK>
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
Read of size 8 at addr ffff88812d962278 by task syz-executor/564
CPU: 1 PID: 564 Comm: syz-executor Tainted: G W 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x158 lib/dump_stack.c:106
print_address_description+0x71/0x210 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:427
kasan_report+0x122/0x150 mm/kasan/report.c:531
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
__list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
__list_del_entry include/linux/list.h:134 [inline]
list_del_init include/linux/list.h:206 [inline]
f2fs_inode_synced+0xf7/0x2e0 fs/f2fs/super.c:1531
f2fs_update_inode+0x74/0x1c40 fs/f2fs/inode.c:585
f2fs_update_inode_page+0x137/0x170 fs/f2fs/inode.c:703
f2fs_write_inode+0x4ec/0x770 fs/f2fs/inode.c:731
write_inode fs/fs-writeback.c:1460 [inline]
__writeback_single_inode+0x4a0/0xab0 fs/fs-writeback.c:1677
writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
sync_inode_metadata+0xb6/0x110 fs/fs-writeback.c:2789
f2fs_sync_inode_meta+0x16d/0x2a0 fs/f2fs/checkpoint.c:1159
block_operations fs/f2fs/checkpoint.c:1269 [inline]
f2fs_write_checkpoint+0xca3/0x2100 fs/f2fs/checkpoint.c:1658
kill_f2fs_super+0x231/0x390 fs/f2fs/super.c:4668
deactivate_locked_super+0x98/0x100 fs/super.c:332
deactivate_super+0xaf/0xe0 fs/super.c:363
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1186
__cleanup_mnt+0x19/0x20 fs/namespace.c:1193
task_work_run+0x1c6/0x230 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x9fb/0x2410 kernel/exit.c:871
do_group_exit+0x210/0x2d0 kernel/exit.c:1021
__do_sys_exit_group kernel/exit.c:1032 [inline]
__se_sys_exit_group kernel/exit.c:1030 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1030
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f28b1b8e169
Code: Unable to access opcode bytes at 0x7f28b1b8e13f.
RSP: 002b:00007ffe174710a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f28b1c10879 RCX: 00007f28b1b8e169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 00007ffe1746ee47 R09: 00007ffe17472360
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffe17472360
R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520
</TASK>
Allocated by task 569:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4f/0x2c0 mm/slab.h:737
slab_alloc_node mm/slub.c:3398 [inline]
slab_alloc mm/slub.c:3406 [inline]
__kmem_cache_alloc_lru mm/slub.c:3413 [inline]
kmem_cache_alloc_lru+0x104/0x220 mm/slub.c:3429
alloc_inode_sb include/linux/fs.h:3245 [inline]
f2fs_alloc_inode+0x2d/0x340 fs/f2fs/super.c:1419
alloc_inode fs/inode.c:261 [inline]
iget_locked+0x186/0x880 fs/inode.c:1373
f2fs_iget+0x55/0x4c60 fs/f2fs/inode.c:483
f2fs_lookup+0x366/0xab0 fs/f2fs/namei.c:487
__lookup_slow+0x2a3/0x3d0 fs/namei.c:1690
lookup_slow+0x57/0x70 fs/namei.c:1707
walk_component+0x2e6/0x410 fs/namei
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
x86/sev: Evict cache lines during SNP memory validation
An SNP cache coherency vulnerability requires a cache line eviction
mitigation when validating memory after a page state change to private.
The specific mitigation is to touch the first and last byte of each 4K
page that is being validated. There is no need to perform the mitigation
when performing a page state change to shared and rescinding validation.
CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit
that, when set, indicates that the software mitigation for this
vulnerability is not needed.
Implement the mitigation and invoke it when validating memory (making it
private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP
guest is vulnerable. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: make fallback action and fallback decision atomic
Syzkaller reported the following splat:
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 __mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 check_fully_established net/mptcp/options.c:982 [inline]
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Modules linked in:
CPU: 1 UID: 0 PID: 7704 Comm: syz.3.1419 Not tainted 6.16.0-rc3-gbd5ce2324dba #20 PREEMPT(voluntary)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
RIP: 0010:mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
RIP: 0010:check_fully_established net/mptcp/options.c:982 [inline]
RIP: 0010:mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
Code: 24 18 e8 bb 2a 00 fd e9 1b df ff ff e8 b1 21 0f 00 e8 ec 5f c4 fc 44 0f b7 ac 24 b0 00 00 00 e9 54 f1 ff ff e8 d9 5f c4 fc 90 <0f> 0b 90 e9 b8 f4 ff ff e8 8b 2a 00 fd e9 8d e6 ff ff e8 81 2a 00
RSP: 0018:ffff8880a3f08448 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880180a8000 RCX: ffffffff84afcf45
RDX: ffff888090223700 RSI: ffffffff84afdaa7 RDI: 0000000000000001
RBP: ffff888017955780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880180a8910 R14: ffff8880a3e9d058 R15: 0000000000000000
FS: 00005555791b8500(0000) GS:ffff88811c495000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2800b7 CR3: 0000000058e44000 CR4: 0000000000350ef0
Call Trace:
<IRQ>
tcp_reset+0x26f/0x2b0 net/ipv4/tcp_input.c:4432
tcp_validate_incoming+0x1057/0x1b60 net/ipv4/tcp_input.c:5975
tcp_rcv_established+0x5b5/0x21f0 net/ipv4/tcp_input.c:6166
tcp_v4_do_rcv+0x5dc/0xa70 net/ipv4/tcp_ipv4.c:1925
tcp_v4_rcv+0x3473/0x44a0 net/ipv4/tcp_ipv4.c:2363
ip_protocol_deliver_rcu+0xba/0x480 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2f1/0x500 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_local_deliver+0x1be/0x560 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:469 [inline]
ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_rcv+0x514/0x810 net/ipv4/ip_input.c:567
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5975
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6088
process_backlog+0x301/0x1360 net/core/dev.c:6440
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7453
napi_poll net/core/dev.c:7517 [inline]
net_rx_action+0xb44/0x1010 net/core/dev.c:7644
handle_softirqs+0x1d0/0x770 kernel/softirq.c:579
do_softirq+0x3f/0x90 kernel/softirq.c:480
</IRQ>
<TASK>
__local_bh_enable_ip+0xed/0x110 kernel/softirq.c:407
local_bh_enable include/linux/bottom_half.h:33 [inline]
inet_csk_listen_stop+0x2c5/0x1070 net/ipv4/inet_connection_sock.c:1524
mptcp_check_listen_stop.part.0+0x1cc/0x220 net/mptcp/protocol.c:2985
mptcp_check_listen_stop net/mptcp/mib.h:118 [inline]
__mptcp_close+0x9b9/0xbd0 net/mptcp/protocol.c:3000
mptcp_close+0x2f/0x140 net/mptcp/protocol.c:3066
inet_release+0xed/0x200 net/ipv4/af_inet.c:435
inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x402/0xb70 fs/file_table.c:465
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xd4
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
comedi: Fix initialization of data for instructions that write to subdevice
Some Comedi subdevice instruction handlers are known to access
instruction data elements beyond the first `insn->n` elements in some
cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions
allocate at least `MIN_SAMPLES` (16) data elements to deal with this,
but they do not initialize all of that. For Comedi instruction codes
that write to the subdevice, the first `insn->n` data elements are
copied from user-space, but the remaining elements are left
uninitialized. That could be a problem if the subdevice instruction
handler reads the uninitialized data. Ensure that the first
`MIN_SAMPLES` elements are initialized before calling these instruction
handlers, filling the uncopied elements with 0. For
`do_insnlist_ioctl()`, the same data buffer elements are used for
handling a list of instructions, so ensure the first `MIN_SAMPLES`
elements are initialized for each instruction that writes to the
subdevice. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: Fix race condition on qfq_aggregate
A race condition can occur when 'agg' is modified in qfq_change_agg
(called during qfq_enqueue) while other threads access it
concurrently. For example, qfq_dump_class may trigger a NULL
dereference, and qfq_delete_class may cause a use-after-free.
This patch addresses the issue by:
1. Moved qfq_destroy_class into the critical section.
2. Added sch_tree_lock protection to qfq_dump_class and
qfq_dump_class_stats. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
A crash in conntrack was reported while trying to unlink the conntrack
entry from the hash bucket list:
[exception RIP: __nf_ct_delete_from_lists+172]
[..]
#7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack]
#8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack]
#9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack]
[..]
The nf_conn struct is marked as allocated from slab but appears to be in
a partially initialised state:
ct hlist pointer is garbage; looks like the ct hash value
(hence crash).
ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected
ct->timeout is 30000 (=30s), which is unexpected.
Everything else looks like normal udp conntrack entry. If we ignore
ct->status and pretend its 0, the entry matches those that are newly
allocated but not yet inserted into the hash:
- ct hlist pointers are overloaded and store/cache the raw tuple hash
- ct->timeout matches the relative time expected for a new udp flow
rather than the absolute 'jiffies' value.
If it were not for the presence of IPS_CONFIRMED,
__nf_conntrack_find_get() would have skipped the entry.
Theory is that we did hit following race:
cpu x cpu y cpu z
found entry E found entry E
E is expired <preemption>
nf_ct_delete()
return E to rcu slab
init_conntrack
E is re-inited,
ct->status set to 0
reply tuplehash hnnode.pprev
stores hash value.
cpu y found E right before it was deleted on cpu x.
E is now re-inited on cpu z. cpu y was preempted before
checking for expiry and/or confirm bit.
->refcnt set to 1
E now owned by skb
->timeout set to 30000
If cpu y were to resume now, it would observe E as
expired but would skip E due to missing CONFIRMED bit.
nf_conntrack_confirm gets called
sets: ct->status |= CONFIRMED
This is wrong: E is not yet added
to hashtable.
cpu y resumes, it observes E as expired but CONFIRMED:
<resumes>
nf_ct_expired()
-> yes (ct->timeout is 30s)
confirmed bit set.
cpu y will try to delete E from the hashtable:
nf_ct_delete() -> set DYING bit
__nf_ct_delete_from_lists
Even this scenario doesn't guarantee a crash:
cpu z still holds the table bucket lock(s) so y blocks:
wait for spinlock held by z
CONFIRMED is set but there is no
guarantee ct will be added to hash:
"chaintoolong" or "clash resolution"
logic both skip the insert step.
reply hnnode.pprev still stores the
hash value.
unlocks spinlock
return NF_DROP
<unblocks, then
crashes on hlist_nulls_del_rcu pprev>
In case CPU z does insert the entry into the hashtable, cpu y will unlink
E again right away but no crash occurs.
Without 'cpu y' race, 'garbage' hlist is of no consequence:
ct refcnt remains at 1, eventually skb will be free'd and E gets
destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy.
To resolve this, move the IPS_CONFIRMED assignment after the table
insertion but before the unlock.
Pablo points out that the confirm-bit-store could be reordered to happen
before hlist add resp. the timeout fixup, so switch to set_bit and
before_atomic memory barrier to prevent this.
It doesn't matter if other CPUs can observe a newly inserted entry right
before the CONFIRMED bit was set:
Such event cannot be distinguished from above "E is the old incarnation"
case: the entry will be skipped.
Also change nf_ct_should_gc() to first check the confirmed bit.
The gc sequence is:
1. Check if entry has expired, if not skip to next entry
2. Obtain a reference to the expired entry.
3. Call nf_ct_should_gc() to double-check step 1.
nf_ct_should_gc() is thus called only for entries that already failed an
expiry check. After this patch, once the confirmed bit check pas
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
smb: Log an error when close_all_cached_dirs fails
Under low-memory conditions, close_all_cached_dirs() can't move the
dentries to a separate list to dput() them once the locks are dropped.
This will result in a "Dentry still in use" error, so add an error
message that makes it clear this is what happened:
[ 495.281119] CIFS: VFS: \\otters.example.com\share Out of memory while dropping dentries
[ 495.281595] ------------[ cut here ]------------
[ 495.281887] BUG: Dentry ffff888115531138{i=78,n=/} still in use (2) [unmount of cifs cifs]
[ 495.282391] WARNING: CPU: 1 PID: 2329 at fs/dcache.c:1536 umount_check+0xc8/0xf0
Also, bail out of looping through all tcons as soon as a single
allocation fails, since we're already in trouble, and kmalloc() attempts
for subseqeuent tcons are likely to fail just like the first one did. |
| In the Linux kernel, the following vulnerability has been resolved:
net: clear the dst when changing skb protocol
A not-so-careful NAT46 BPF program can crash the kernel
if it indiscriminately flips ingress packets from v4 to v6:
BUG: kernel NULL pointer dereference, address: 0000000000000000
ip6_rcv_core (net/ipv6/ip6_input.c:190:20)
ipv6_rcv (net/ipv6/ip6_input.c:306:8)
process_backlog (net/core/dev.c:6186:4)
napi_poll (net/core/dev.c:6906:9)
net_rx_action (net/core/dev.c:7028:13)
do_softirq (kernel/softirq.c:462:3)
netif_rx (net/core/dev.c:5326:3)
dev_loopback_xmit (net/core/dev.c:4015:2)
ip_mc_finish_output (net/ipv4/ip_output.c:363:8)
NF_HOOK (./include/linux/netfilter.h:314:9)
ip_mc_output (net/ipv4/ip_output.c:400:5)
dst_output (./include/net/dst.h:459:9)
ip_local_out (net/ipv4/ip_output.c:130:9)
ip_send_skb (net/ipv4/ip_output.c:1496:8)
udp_send_skb (net/ipv4/udp.c:1040:8)
udp_sendmsg (net/ipv4/udp.c:1328:10)
The output interface has a 4->6 program attached at ingress.
We try to loop the multicast skb back to the sending socket.
Ingress BPF runs as part of netif_rx(), pushes a valid v6 hdr
and changes skb->protocol to v6. We enter ip6_rcv_core which
tries to use skb_dst(). But the dst is still an IPv4 one left
after IPv4 mcast output.
Clear the dst in all BPF helpers which change the protocol.
Try to preserve metadata dsts, those may carry non-routing
metadata. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
huge_pmd_unshare() drops a reference on a page table that may have
previously been shared across processes, potentially turning it into a
normal page table used in another process in which unrelated VMAs can
afterwards be installed.
If this happens in the middle of a concurrent gup_fast(), gup_fast() could
end up walking the page tables of another process. While I don't see any
way in which that immediately leads to kernel memory corruption, it is
really weird and unexpected.
Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(),
just like we do in khugepaged when removing page tables for a THP
collapse. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: unshare page tables during VMA split, not before
Currently, __split_vma() triggers hugetlb page table unsharing through
vm_ops->may_split(). This happens before the VMA lock and rmap locks are
taken - which is too early, it allows racing VMA-locked page faults in our
process and racing rmap walks from other processes to cause page tables to
be shared again before we actually perform the split.
Fix it by explicitly calling into the hugetlb unshare logic from
__split_vma() in the same place where THP splitting also happens. At that
point, both the VMA and the rmap(s) are write-locked.
An annoying detail is that we can now call into the helper
hugetlb_unshare_pmds() from two different locking contexts:
1. from hugetlb_split(), holding:
- mmap lock (exclusively)
- VMA lock
- file rmap lock (exclusively)
2. hugetlb_unshare_all_pmds(), which I think is designed to be able to
call us with only the mmap lock held (in shared mode), but currently
only runs while holding mmap lock (exclusively) and VMA lock
Backporting note:
This commit fixes a racy protection that was introduced in commit
b30c14cd6102 ("hugetlb: unshare some PMDs when splitting VMAs"); that
commit claimed to fix an issue introduced in 5.13, but it should actually
also go all the way back.
[jannh@google.com: v2] |
| In the Linux kernel, the following vulnerability has been resolved:
net_sched: prio: fix a race in prio_tune()
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost-scsi: protect vq->log_used with vq->mutex
The vhost-scsi completion path may access vq->log_base when vq->log_used is
already set to false.
vhost-thread QEMU-thread
vhost_scsi_complete_cmd_work()
-> vhost_add_used()
-> vhost_add_used_n()
if (unlikely(vq->log_used))
QEMU disables vq->log_used
via VHOST_SET_VRING_ADDR.
mutex_lock(&vq->mutex);
vq->log_used = false now!
mutex_unlock(&vq->mutex);
QEMU gfree(vq->log_base)
log_used()
-> log_write(vq->log_base)
Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be
reclaimed via gfree(). As a result, this causes invalid memory writes to
QEMU userspace.
The control queue path has the same issue. |
| In the Linux kernel, the following vulnerability has been resolved:
orangefs: Do not truncate file size
'len' is used to store the result of i_size_read(), so making 'len'
a size_t results in truncation to 4GiB on 32-bit systems. |
