Security Vulnerabilities
- CVEs Published In January 2025
In the Linux kernel, the following vulnerability has been resolved:
net_sched: cls_flow: validate TCA_FLOW_RSHIFT attribute
syzbot found that TCA_FLOW_RSHIFT attribute was not validated.
Right shitfing a 32bit integer is undefined for large shift values.
UBSAN: shift-out-of-bounds in net/sched/cls_flow.c:329:23
shift exponent 9445 is too large for 32-bit type 'u32' (aka 'unsigned int')
CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.13.0-rc3-syzkaller-00180-g4f619d518db9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
flow_classify+0x24d5/0x25b0 net/sched/cls_flow.c:329
tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1771 [inline]
tcf_classify+0x420/0x1160 net/sched/cls_api.c:1867
sfb_classify net/sched/sch_sfb.c:260 [inline]
sfb_enqueue+0x3ad/0x18b0 net/sched/sch_sfb.c:318
dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:3793
__dev_xmit_skb net/core/dev.c:3889 [inline]
__dev_queue_xmit+0xf0e/0x3f50 net/core/dev.c:4400
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
neigh_hh_output include/net/neighbour.h:523 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236
iptunnel_xmit+0x55d/0x9b0 net/ipv4/ip_tunnel_core.c:82
udp_tunnel_xmit_skb+0x262/0x3b0 net/ipv4/udp_tunnel_core.c:173
geneve_xmit_skb drivers/net/geneve.c:916 [inline]
geneve_xmit+0x21dc/0x2d00 drivers/net/geneve.c:1039
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3606
__dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434
In the Linux kernel, the following vulnerability has been resolved:
rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The per-netns structure can be obtained from the table->data using
container_of(), then the 'net' one can be retrieved from the listen
socket (if available).
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.probe_interval' is
used.
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: udp_port: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: auth_enable: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: rto_min/max: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used.
In the Linux kernel, the following vulnerability has been resolved:
sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is
used.
In the Linux kernel, the following vulnerability has been resolved:
mptcp: sysctl: blackhole timeout: avoid using current->nsproxy
As mentioned in the previous commit, using the 'net' structure via
'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'pernet' structure can be obtained from the table->data using
container_of().
In the Linux kernel, the following vulnerability has been resolved:
mptcp: sysctl: sched: avoid using current->nsproxy
Using the 'net' structure via 'current' is not recommended for different
reasons.
First, if the goal is to use it to read or write per-netns data, this is
inconsistent with how the "generic" sysctl entries are doing: directly
by only using pointers set to the table entry, e.g. table->data. Linked
to that, the per-netns data should always be obtained from the table
linked to the netns it had been created for, which may not coincide with
the reader's or writer's netns.
Another reason is that access to current->nsproxy->netns can oops if
attempted when current->nsproxy had been dropped when the current task
is exiting. This is what syzbot found, when using acct(2):
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 UID: 0 PID: 5924 Comm: syz-executor Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:proc_scheduler+0xc6/0x3c0 net/mptcp/ctrl.c:125
Code: 03 42 80 3c 38 00 0f 85 fe 02 00 00 4d 8b a4 24 08 09 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 cc 02 00 00 4d 8b 7c 24 28 48 8d 84 24 c8 00 00
RSP: 0018:ffffc900034774e8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 1ffff9200068ee9e RCX: ffffc90003477620
RDX: 0000000000000005 RSI: ffffffff8b08f91e RDI: 0000000000000028
RBP: 0000000000000001 R08: ffffc90003477710 R09: 0000000000000040
R10: 0000000000000040 R11: 00000000726f7475 R12: 0000000000000000
R13: ffffc90003477620 R14: ffffc90003477710 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee3cd452d8 CR3: 000000007d116000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
proc_sys_call_handler+0x403/0x5d0 fs/proc/proc_sysctl.c:601
__kernel_write_iter+0x318/0xa80 fs/read_write.c:612
__kernel_write+0xf6/0x140 fs/read_write.c:632
do_acct_process+0xcb0/0x14a0 kernel/acct.c:539
acct_pin_kill+0x2d/0x100 kernel/acct.c:192
pin_kill+0x194/0x7c0 fs/fs_pin.c:44
mnt_pin_kill+0x61/0x1e0 fs/fs_pin.c:81
cleanup_mnt+0x3ac/0x450 fs/namespace.c:1366
task_work_run+0x14e/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0xad8/0x2d70 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
get_signal+0x2576/0x2610 kernel/signal.c:3017
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee3cb87a6a
Code: Unable to access opcode bytes at 0x7fee3cb87a40.
RSP: 002b:00007fffcccac688 EFLAGS: 00000202 ORIG_RAX: 0000000000000037
RAX: 0000000000000000 RBX: 00007fffcccac710 RCX: 00007fee3cb87a6a
RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fffcccac6ac R09: 00007fffcccacac7
R10: 00007fffcccac710 R11: 0000000000000202 R12: 00007fee3cd49500
R13: 00007fffcccac6ac R14: 0000000000000000 R15: 00007fee3cd4b000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:proc_scheduler+0xc6/0x3c0 net/mptcp/ctrl.c:125
Code: 03 42 80 3c 38 00 0f 85 fe 02 00 00 4d 8b a4 24 08 09 00 00 48 b8 00 00 00 00 00 fc
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix kernel async DIO
Netfslib needs to be able to handle kernel-initiated asynchronous DIO that
is supplied with a bio_vec[] array. Currently, because of the async flag,
this gets passed to netfs_extract_user_iter() which throws a warning and
fails because it only handles IOVEC and UBUF iterators. This can be
triggered through a combination of cifs and a loopback blockdev with
something like:
mount //my/cifs/share /foo
dd if=/dev/zero of=/foo/m0 bs=4K count=1K
losetup --sector-size 4096 --direct-io=on /dev/loop2046 /foo/m0
echo hello >/dev/loop2046
This causes the following to appear in syslog:
WARNING: CPU: 2 PID: 109 at fs/netfs/iterator.c:50 netfs_extract_user_iter+0x170/0x250 [netfs]
and the write to fail.
Fix this by removing the check in netfs_unbuffered_write_iter_locked() that
causes async kernel DIO writes to be handled as userspace writes. Note
that this change relies on the kernel caller maintaining the existence of
the bio_vec array (or kvec[] or folio_queue) until the op is complete.