Linux: >> Linux Kernel >> 2.6.28.9 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ax25: Remove broken autobind
Binding AX25 socket by using the autobind feature leads to memory leaks
in ax25_connect() and also refcount leaks in ax25_release(). Memory
leak was detected with kmemleak:
================================================================
unreferenced object 0xffff8880253cd680 (size 96):
backtrace:
__kmalloc_node_track_caller_noprof (./include/linux/kmemleak.h:43)
kmemdup_noprof (mm/util.c:136)
ax25_rt_autobind (net/ax25/ax25_route.c:428)
ax25_connect (net/ax25/af_ax25.c:1282)
__sys_connect_file (net/socket.c:2045)
__sys_connect (net/socket.c:2064)
__x64_sys_connect (net/socket.c:2067)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
================================================================
When socket is bound, refcounts must be incremented the way it is done
in ax25_bind() and ax25_setsockopt() (SO_BINDTODEVICE). In case of
autobind, the refcounts are not incremented.
This bug leads to the following issue reported by Syzkaller:
================================================================
ax25_connect(): syz-executor318 uses autobind, please contact jreuter@yaina.de
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 5317 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz-executor318 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
...
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:336 [inline]
refcount_dec include/linux/refcount.h:351 [inline]
ref_tracker_free+0x6af/0x7e0 lib/ref_tracker.c:236
netdev_tracker_free include/linux/netdevice.h:4302 [inline]
netdev_put include/linux/netdevice.h:4319 [inline]
ax25_release+0x368/0x960 net/ax25/af_ax25.c:1080
__sock_release net/socket.c:647 [inline]
sock_close+0xbc/0x240 net/socket.c:1398
__fput+0x3e9/0x9f0 fs/file_table.c:464
__do_sys_close fs/open.c:1580 [inline]
__se_sys_close fs/open.c:1565 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1565
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
...
</TASK>
================================================================
Considering the issues above and the comments left in the code that say:
"check if we can remove this feature. It is broken."; "autobinding in this
may or may not work"; - it is better to completely remove this feature than
to fix it because it is broken and leads to various kinds of memory bugs.
Now calling connect() without first binding socket will result in an
error (-EINVAL). Userspace software that relies on the autobind feature
might get broken. However, this feature does not seem widely used with
this specific driver as it was not reliable at any point of time, and it
is already broken anyway. E.g. ax25-tools and ax25-apps packages for
popular distributions do not use the autobind feature for AF_AX25.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate l_tree_depth to avoid out-of-bounds access
The l_tree_depth field is 16-bit (__le16), but the actual maximum depth is
limited to OCFS2_MAX_PATH_DEPTH.
Add a check to prevent out-of-bounds access if l_tree_depth has an invalid
value, which may occur when reading from a corrupted mounted disk [1].
CVSS Score
7.1
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
spufs: fix a leak in spufs_create_context()
Leak fixes back in 2008 missed one case - if we are trying to set affinity
and spufs_mkdir() fails, we need to drop the reference to neighbor.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
spufs: fix gang directory lifetimes
prior to "[POWERPC] spufs: Fix gang destroy leaks" we used to have
a problem with gang lifetimes - creation of a gang returns opened
gang directory, which normally gets removed when that gets closed,
but if somebody has created a context belonging to that gang and
kept it alive until the gang got closed, removal failed and we
ended up with a leak.
Unfortunately, it had been fixed the wrong way. Dentry of gang
directory was no longer pinned, and rmdir on close was gone.
One problem was that failure of open kept calling simple_rmdir()
as cleanup, which meant an unbalanced dput(). Another bug was
in the success case - gang creation incremented link count on
root directory, but that was no longer undone when gang got
destroyed.
Fix consists of
* reverting the commit in question
* adding a counter to gang, protected by ->i_rwsem
of gang directory inode.
* having it set to 1 at creation time, dropped
in both spufs_dir_close() and spufs_gang_close() and bumped
in spufs_create_context(), provided that it's not 0.
* using simple_recursive_removal() to take the gang
directory out when counter reaches zero.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
spufs: fix a leak on spufs_new_file() failure
It's called from spufs_fill_dir(), and caller of that will do
spufs_rmdir() in case of failure. That does remove everything
we'd managed to create, but... the problem dentry is still
negative. IOW, it needs to be explicitly dropped.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
net: ibmveth: make veth_pool_store stop hanging
v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text
Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.
Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.
I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:
Setting pool0/active to 0
Setting pool1/active to 1
[ 73.911067][ T4365] ibmveth 30000002 eth0: close starting
Setting pool1/active to 1
Setting pool1/active to 0
[ 73.911367][ T4366] ibmveth 30000002 eth0: close starting
[ 73.916056][ T4365] ibmveth 30000002 eth0: close complete
[ 73.916064][ T4365] ibmveth 30000002 eth0: open starting
[ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
[ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8
[ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000
[ 243.683852][ T123] Call Trace:
[ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
[ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
[ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
[ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
[ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
[ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
[ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
[ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
[ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
[ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
[ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
[ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
[ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
[ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
[ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
...
[ 243.684087][ T123] Showing all locks held in the system:
[ 243.684095][ T123] 1 lock held by khungtaskd/123:
[ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
[ 243.684114][ T123] 4 locks held by stress.sh/4365:
[ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
[ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
[ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
[ 243.684166][ T123] 5 locks held by stress.sh/4366:
[ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix null pointer dereference in alloc_preauth_hash()
The Client send malformed smb2 negotiate request. ksmbd return error
response. Subsequently, the client can send smb2 session setup even
thought conn->preauth_info is not allocated.
This patch add KSMBD_SESS_NEED_SETUP status of connection to ignore
session setup request if smb2 negotiate phase is not complete.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate zero num_subauth before sub_auth is accessed
Access psid->sub_auth[psid->num_subauth - 1] without checking
if num_subauth is non-zero leads to an out-of-bounds read.
This patch adds a validation step to ensure num_subauth != 0
before sub_auth is accessed.
CVSS Score
7.1
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix session use-after-free in multichannel connection
There is a race condition between session setup and
ksmbd_sessions_deregister. The session can be freed before the connection
is added to channel list of session.
This patch check reference count of session before freeing it.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in ksmbd_sessions_deregister()
In multichannel mode, UAF issue can occur in session_deregister
when the second channel sets up a session through the connection of
the first channel. session that is freed through the global session
table can be accessed again through ->sessions of connection.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-04-16