Linux: >> Linux Kernel >> 3.18.101 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: appletalk: Fix use-after-free in AARP proxy probe
The AARP proxyâprobe routine (aarp_proxy_probe_network) sends a probe,
releases the aarp_lock, sleeps, then re-acquires the lock. During that
window an expire timer thread (__aarp_expire_timer) can remove and
kfree() the same entry, leading to a use-after-free.
race condition:
cpu 0 | cpu 1
atalk_sendmsg() | atif_proxy_probe_device()
aarp_send_ddp() | aarp_proxy_probe_network()
mod_timer() | lock(aarp_lock) // LOCK!!
timeout around 200ms | alloc(aarp_entry)
and then call | proxies[hash] = aarp_entry
aarp_expire_timeout() | aarp_send_probe()
| unlock(aarp_lock) // UNLOCK!!
lock(aarp_lock) // LOCK!! | msleep(100);
__aarp_expire_timer(&proxies[ct]) |
free(aarp_entry) |
unlock(aarp_lock) // UNLOCK!! |
| lock(aarp_lock) // LOCK!!
| UAF aarp_entry !!
==================================================================
BUG: KASAN: slab-use-after-free in aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493
Read of size 4 at addr ffff8880123aa360 by task repro/13278
CPU: 3 UID: 0 PID: 13278 Comm: repro Not tainted 6.15.2 #3 PREEMPT(full)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc1/0x630 mm/kasan/report.c:521
kasan_report+0xca/0x100 mm/kasan/report.c:634
aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493
atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]
atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857
atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818
sock_do_ioctl+0xdc/0x260 net/socket.c:1190
sock_ioctl+0x239/0x6a0 net/socket.c:1311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x194/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcb/0x250 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated:
aarp_alloc net/appletalk/aarp.c:382 [inline]
aarp_proxy_probe_network+0xd8/0x630 net/appletalk/aarp.c:468
atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]
atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857
atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818
Freed:
kfree+0x148/0x4d0 mm/slub.c:4841
__aarp_expire net/appletalk/aarp.c:90 [inline]
__aarp_expire_timer net/appletalk/aarp.c:261 [inline]
aarp_expire_timeout+0x480/0x6e0 net/appletalk/aarp.c:317
The buggy address belongs to the object at ffff8880123aa300
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 96 bytes inside of
freed 192-byte region [ffff8880123aa300, ffff8880123aa3c0)
Memory state around the buggy address:
ffff8880123aa200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880123aa280: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880123aa300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880123aa380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff8880123aa400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject invalid file types when reading inodes
To prevent inodes with invalid file types from tripping through the vfs
and causing malfunctions or assertion failures, add a missing sanity check
when reading an inode from a block device. If the file type is not valid,
treat it as a filesystem error.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode
Andrei Lalaev reported a NULL pointer deref when a CAN device is
restarted from Bus Off and the driver does not implement the struct
can_priv::do_set_mode callback.
There are 2 code path that call struct can_priv::do_set_mode:
- directly by a manual restart from the user space, via
can_changelink()
- delayed automatic restart after bus off (deactivated by default)
To prevent the NULL pointer deference, refuse a manual restart or
configure the automatic restart delay in can_changelink() and report
the error via extack to user space.
As an additional safety measure let can_restart() return an error if
can_priv::do_set_mode is not set instead of dereferencing it
unchecked.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: reject TDLS operations when station is not associated
syzbot triggered a WARN in ieee80211_tdls_oper() by sending
NL80211_TDLS_ENABLE_LINK immediately after NL80211_CMD_CONNECT,
before association completed and without prior TDLS setup.
This left internal state like sdata->u.mgd.tdls_peer uninitialized,
leading to a WARN_ON() in code paths that assumed it was valid.
Reject the operation early if not in station mode or not associated.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_nfacct: don't assume acct name is null-terminated
BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721
Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851
[..]
string+0x231/0x2b0 lib/vsprintf.c:721
vsnprintf+0x739/0xf00 lib/vsprintf.c:2874
[..]
nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41
xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523
nfnl_acct_find_get() handles non-null input, but the error
printk relied on its presence.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
fbdev: imxfb: Check fb_add_videomode to prevent null-ptr-deref
fb_add_videomode() can fail with -ENOMEM when its internal kmalloc() cannot
allocate a struct fb_modelist. If that happens, the modelist stays empty but
the driver continues to register. Add a check for its return value to prevent
poteintial null-ptr-deref, which is similar to the commit 17186f1f90d3 ("fbdev:
Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var").
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
net/packet: fix a race in packet_set_ring() and packet_notifier()
When packet_set_ring() releases po->bind_lock, another thread can
run packet_notifier() and process an NETDEV_UP event.
This race and the fix are both similar to that of commit 15fe076edea7
("net/packet: fix a race in packet_bind() and packet_notifier()").
There too the packet_notifier NETDEV_UP event managed to run while a
po->bind_lock critical section had to be temporarily released. And
the fix was similarly to temporarily set po->num to zero to keep
the socket unhooked until the lock is retaken.
The po->bind_lock in packet_set_ring and packet_notifier precede the
introduction of git history.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
vsock: Do not allow binding to VMADDR_PORT_ANY
It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can
cause a use-after-free when a connection is made to the bound socket.
The socket returned by accept() also has port VMADDR_PORT_ANY but is not
on the list of unbound sockets. Binding it will result in an extra
refcount decrement similar to the one fixed in fcdd2242c023 (vsock: Keep
the binding until socket destruction).
Modify the check in __vsock_bind_connectible() to also prevent binding
to VMADDR_PORT_ANY.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-22
In the Linux kernel, the following vulnerability has been resolved:
eventpoll: Fix semi-unbounded recursion
Ensure that epoll instances can never form a graph deeper than
EP_MAX_NESTS+1 links.
Currently, ep_loop_check_proc() ensures that the graph is loop-free and
does some recursion depth checks, but those recursion depth checks don't
limit the depth of the resulting tree for two reasons:
- They don't look upwards in the tree.
- If there are multiple downwards paths of different lengths, only one of
the paths is actually considered for the depth check since commit
28d82dc1c4ed ("epoll: limit paths").
Essentially, the current recursion depth check in ep_loop_check_proc() just
serves to prevent it from recursing too deeply while checking for loops.
A more thorough check is done in reverse_path_check() after the new graph
edge has already been created; this checks, among other things, that no
paths going upwards from any non-epoll file with a length of more than 5
edges exist. However, this check does not apply to non-epoll files.
As a result, it is possible to recurse to a depth of at least roughly 500,
tested on v6.15. (I am unsure if deeper recursion is possible; and this may
have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion
problem").)
To fix it:
1. In ep_loop_check_proc(), note the subtree depth of each visited node,
and use subtree depths for the total depth calculation even when a subtree
has already been visited.
2. Add ep_get_upwards_depth_proc() for similarly determining the maximum
depth of an upwards walk.
3. In ep_loop_check(), use these values to limit the total path length
between epoll nodes to EP_MAX_NESTS edges.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
iwlwifi: Add missing check for alloc_ordered_workqueue
Add check for the return value of alloc_ordered_workqueue since it may
return NULL pointer.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19