Linux: >> Linux Kernel >> 2.6.31 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix nfs4_openowner leak when concurrent nfsd4_open occur
The action force umount(umount -f) will attempt to kill all rpc_task even
umount operation may ultimately fail if some files remain open.
Consequently, if an action attempts to open a file, it can potentially
send two rpc_task to nfs server.
NFS CLIENT
thread1 thread2
open("file")
...
nfs4_do_open
_nfs4_do_open
_nfs4_open_and_get_state
_nfs4_proc_open
nfs4_run_open_task
/* rpc_task1 */
rpc_run_task
rpc_wait_for_completion_task
umount -f
nfs_umount_begin
rpc_killall_tasks
rpc_signal_task
rpc_task1 been wakeup
and return -512
_nfs4_do_open // while loop
...
nfs4_run_open_task
/* rpc_task2 */
rpc_run_task
rpc_wait_for_completion_task
While processing an open request, nfsd will first attempt to find or
allocate an nfs4_openowner. If it finds an nfs4_openowner that is not
marked as NFS4_OO_CONFIRMED, this nfs4_openowner will released. Since
two rpc_task can attempt to open the same file simultaneously from the
client to server, and because two instances of nfsd can run
concurrently, this situation can lead to lots of memory leak.
Additionally, when we echo 0 to /proc/fs/nfsd/threads, warning will be
triggered.
NFS SERVER
nfsd1 nfsd2 echo 0 > /proc/fs/nfsd/threads
nfsd4_open
nfsd4_process_open1
find_or_alloc_open_stateowner
// alloc oo1, stateid1
nfsd4_open
nfsd4_process_open1
find_or_alloc_open_stateowner
// find oo1, without NFS4_OO_CONFIRMED
release_openowner
unhash_openowner_locked
list_del_init(&oo->oo_perclient)
// cannot find this oo
// from client, LEAK!!!
alloc_stateowner // alloc oo2
nfsd4_process_open2
init_open_stateid
// associate oo1
// with stateid1, stateid1 LEAK!!!
nfs4_get_vfs_file
// alloc nfsd_file1 and nfsd_file_mark1
// all LEAK!!!
nfsd4_process_open2
...
write_threads
...
nfsd_destroy_serv
nfsd_shutdown_net
nfs4_state_shutdown_net
nfs4_state_destroy_net
destroy_client
__destroy_client
// won't find oo1!!!
nfsd_shutdown_generic
nfsd_file_cache_shutdown
kmem_cache_destroy
for nfsd_file_slab
and nfsd_file_mark_slab
// bark since nfsd_file1
// and nfsd_file_mark1
// still alive
=======================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
-----------------------------------------------------------------------
Slab 0xffd4000004438a80 objects=34 used=1 fp=0xff11000110e2ad28
flags=0x17ffffc0000240(workingset|head|node=0|zone=2|lastcpupid=0x1fffff)
CPU: 4 UID: 0 PID: 757 Comm: sh Not tainted 6.12.0-rc6+ #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Call Trace:
<TASK>
dum
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-08
In the Linux kernel, the following vulnerability has been resolved:
media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg
Syzbot reports [1] an uninitialized value issue found by KMSAN in
dib3000_read_reg().
Local u8 rb[2] is used in i2c_transfer() as a read buffer; in case
that call fails, the buffer may end up with some undefined values.
Since no elaborate error handling is expected in dib3000_write_reg(),
simply zero out rb buffer to mitigate the problem.
[1] Syzkaller report
dvb-usb: bulk message failed: -22 (6/0)
=====================================================
BUG: KMSAN: uninit-value in dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
dibusb_dib3000mb_frontend_attach+0x155/0x2f0 drivers/media/usb/dvb-usb/dibusb-mb.c:31
dvb_usb_adapter_frontend_init+0xed/0x9a0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:90 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline]
dvb_usb_device_init+0x25a8/0x3760 drivers/media/usb/dvb-usb/dvb-usb-init.c:310
dibusb_probe+0x46/0x250 drivers/media/usb/dvb-usb/dibusb-mb.c:110
...
Local variable rb created at:
dib3000_read_reg+0x86/0x4e0 drivers/media/dvb-frontends/dib3000mb.c:54
dib3000mb_attach+0x123/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-06
In the Linux kernel, the following vulnerability has been resolved:
tracing: Prevent bad count for tracing_cpumask_write
If a large count is provided, it will trigger a warning in bitmap_parse_user.
Also check zero for it.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-06
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: mediatek: add intf release flow when usb disconnect
MediaTek claim an special usb intr interface for ISO data transmission.
The interface need to be released before unregistering hci device when
usb disconnect. Removing BT usb dongle without properly releasing the
interface may cause Kernel panic while unregister hci device.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-06
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free when COWing tree bock and tracing is enabled
When a COWing a tree block, at btrfs_cow_block(), and we have the
tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled
(CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent
buffer while inside the tracepoint code. This is because in some paths
that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding
the last reference on the extent buffer @buf so btrfs_force_cow_block()
drops the last reference on the @buf extent buffer when it calls
free_extent_buffer_stale(buf), which schedules the release of the extent
buffer with RCU. This means that if we are on a kernel with preemption,
the current task may be preempted before calling trace_btrfs_cow_block()
and the extent buffer already released by the time trace_btrfs_cow_block()
is called, resulting in a use-after-free.
Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to
btrfs_force_cow_block() before the COWed extent buffer is freed.
This also has a side effect of invoking the tracepoint in the tree defrag
code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is
called there, but this is fine and it was actually missing there.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-01-06
In the Linux kernel, the following vulnerability has been resolved:
media: s5p_cec: limit msg.len to CEC_MAX_MSG_SIZE
I expect that the hardware will have limited this to 16, but just in
case it hasn't, check for this corner case.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-02
In the Linux kernel, the following vulnerability has been resolved:
fbdev: sh7760fb: Fix a possible memory leak in sh7760fb_alloc_mem()
When information such as info->screen_base is not ready, calling
sh7760fb_free_mem() does not release memory correctly. Call
dma_free_coherent() instead.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-29
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on node blkaddr in truncate_node()
syzbot reports a f2fs bug as below:
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2534!
RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534
Call Trace:
truncate_node+0x1ae/0x8c0 fs/f2fs/node.c:909
f2fs_remove_inode_page+0x5c2/0x870 fs/f2fs/node.c:1288
f2fs_evict_inode+0x879/0x15c0 fs/f2fs/inode.c:856
evict+0x4e8/0x9b0 fs/inode.c:723
f2fs_handle_failed_inode+0x271/0x2e0 fs/f2fs/inode.c:986
f2fs_create+0x357/0x530 fs/f2fs/namei.c:394
lookup_open fs/namei.c:3595 [inline]
open_last_lookups fs/namei.c:3694 [inline]
path_openat+0x1c03/0x3590 fs/namei.c:3930
do_filp_open+0x235/0x490 fs/namei.c:3960
do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
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: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534
The root cause is: on a fuzzed image, blkaddr in nat entry may be
corrupted, then it will cause system panic when using it in
f2fs_invalidate_blocks(), to avoid this, let's add sanity check on
nat blkaddr in truncate_node().
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-28
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer
Considering that in some extreme cases,
when u_serial driver is accessed by multiple threads,
Thread A is executing the open operation and calling the gs_open,
Thread B is executing the disconnect operation and calling the
gserial_disconnect function,The port->port_usb pointer will be set to NULL.
E.g.
Thread A Thread B
gs_open() gadget_unbind_driver()
gs_start_io() composite_disconnect()
gs_start_rx() gserial_disconnect()
... ...
spin_unlock(&port->port_lock)
status = usb_ep_queue() spin_lock(&port->port_lock)
spin_lock(&port->port_lock) port->port_usb = NULL
gs_free_requests(port->port_usb->in) spin_unlock(&port->port_lock)
Crash
This causes thread A to access a null pointer (port->port_usb is null)
when calling the gs_free_requests function, causing a crash.
If port_usb is NULL, the release request will be skipped as it
will be done by gserial_disconnect.
So add a null pointer check to gs_start_io before attempting
to access the value of the pointer port->port_usb.
Call trace:
gs_start_io+0x164/0x25c
gs_open+0x108/0x13c
tty_open+0x314/0x638
chrdev_open+0x1b8/0x258
do_dentry_open+0x2c4/0x700
vfs_open+0x2c/0x3c
path_openat+0xa64/0xc60
do_filp_open+0xb8/0x164
do_sys_openat2+0x84/0xf0
__arm64_sys_openat+0x70/0x9c
invoke_syscall+0x58/0x114
el0_svc_common+0x80/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x38/0x68
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-27
In the Linux kernel, the following vulnerability has been resolved:
net: lapb: increase LAPB_HEADER_LEN
It is unclear if net/lapb code is supposed to be ready for 8021q.
We can at least avoid crashes like the following :
skbuff: skb_under_panic: text:ffffffff8aabe1f6 len:24 put:20 head:ffff88802824a400 data:ffff88802824a3fe tail:0x16 end:0x140 dev:nr0.2
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5508 Comm: dhcpcd Not tainted 6.12.0-rc7-syzkaller-00144-g66418447d27b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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 2e 9e 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 1a 6f 37 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:ffffc90002ddf638 EFLAGS: 00010282
RAX: 0000000000000086 RBX: dffffc0000000000 RCX: 7a24750e538ff600
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000
RBP: ffff888034a86650 R08: ffffffff8174b13c R09: 1ffff920005bbe60
R10: dffffc0000000000 R11: fffff520005bbe61 R12: 0000000000000140
R13: ffff88802824a400 R14: ffff88802824a3fe R15: 0000000000000016
FS: 00007f2a5990d740(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2631fd CR3: 0000000029504000 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
nr_header+0x36/0x320 net/netrom/nr_dev.c:69
dev_hard_header include/linux/netdevice.h:3148 [inline]
vlan_dev_hard_header+0x359/0x480 net/8021q/vlan_dev.c:83
dev_hard_header include/linux/netdevice.h:3148 [inline]
lapbeth_data_transmit+0x1f6/0x2a0 drivers/net/wan/lapbether.c:257
lapb_data_transmit+0x91/0xb0 net/lapb/lapb_iface.c:447
lapb_transmit_buffer+0x168/0x1f0 net/lapb/lapb_out.c:149
lapb_establish_data_link+0x84/0xd0
lapb_device_event+0x4e0/0x670
notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
__dev_notify_flags+0x207/0x400
dev_change_flags+0xf0/0x1a0 net/core/dev.c:8922
devinet_ioctl+0xa4e/0x1aa0 net/ipv4/devinet.c:1188
inet_ioctl+0x3d7/0x4f0 net/ipv4/af_inet.c:1003
sock_do_ioctl+0x158/0x460 net/socket.c:1227
sock_ioctl+0x626/0x8e0 net/socket.c:1346
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-27