Linux: >> Linux Kernel >> 2.16.12 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
atm: atmtcp: Free invalid length skb in atmtcp_c_send().
syzbot reported the splat below. [0]
vcc_sendmsg() copies data passed from userspace to skb and passes
it to vcc->dev->ops->send().
atmtcp_c_send() accesses skb->data as struct atmtcp_hdr after
checking if skb->len is 0, but it's not enough.
Also, when skb->len == 0, skb and sk (vcc) were leaked because
dev_kfree_skb() is not called and sk_wmem_alloc adjustment is missing
to revert atm_account_tx() in vcc_sendmsg(), which is expected
to be done in atm_pop_raw().
Let's properly free skb with an invalid length in atmtcp_c_send().
[0]:
BUG: KMSAN: uninit-value in atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294
atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294
vcc_sendmsg+0xd7c/0xff0 net/atm/common.c:644
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:727
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566
___sys_sendmsg+0x271/0x3b0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655
x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:4154 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249
kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579
__alloc_skb+0x347/0x7d0 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1336 [inline]
vcc_sendmsg+0xb40/0xff0 net/atm/common.c:628
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:727
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566
___sys_sendmsg+0x271/0x3b0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655
x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 1 UID: 0 PID: 5798 Comm: syz-executor192 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(undef)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
net: atm: fix /proc/net/atm/lec handling
/proc/net/atm/lec must ensure safety against dev_lec[] changes.
It appears it had dev_put() calls without prior dev_hold(),
leading to imbalance and UAF.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
sch_hfsc: make hfsc_qlen_notify() idempotent
hfsc_qlen_notify() is not idempotent either and not friendly
to its callers, like fq_codel_dequeue(). Let's make it idempotent
to ease qdisc_tree_reduce_backlog() callers' life:
1. update_vf() decreases cl->cl_nactive, so we can check whether it is
non-zero before calling it.
2. eltree_remove() always removes RB node cl->el_node, but we can use
RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-04
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Disable SCO support if READ_VOICE_SETTING is unsupported/broken
A SCO connection without the proper voice_setting can cause
the controller to lock up.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-03
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Kill timer properly at removal
The USB-audio MIDI code initializes the timer, but in a rare case, the
driver might be freed without the disconnect call. This leaves the
timer in an active state while the assigned object is released via
snd_usbmidi_free(), which ends up with a kernel warning when the debug
configuration is enabled, as spotted by fuzzer.
For avoiding the problem, put timer_shutdown_sync() at
snd_usbmidi_free(), so that the timer can be killed properly.
While we're at it, replace the existing timer_delete_sync() at the
disconnect callback with timer_shutdown_sync(), too.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-03
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: don't warn when if there is a FW error
iwl_trans_reclaim is warning if it is called when the FW is not alive.
But if it is called when there is a pending restart, i.e. after a FW
error, there is no need to warn, instead - return silently.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-03
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.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-06-28
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]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-28
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Don't BUG if userspace injects an interrupt with GIF=0
Don't BUG/WARN on interrupt injection due to GIF being cleared,
since it's trivial for userspace to force the situation via
KVM_SET_VCPU_EVENTS (even if having at least a WARN there would be correct
for KVM internally generated injections).
kernel BUG at arch/x86/kvm/svm/svm.c:3386!
invalid opcode: 0000 [#1] SMP
CPU: 15 PID: 926 Comm: smm_test Not tainted 5.17.0-rc3+ #264
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:svm_inject_irq+0xab/0xb0 [kvm_amd]
Code: <0f> 0b 0f 1f 00 0f 1f 44 00 00 80 3d ac b3 01 00 00 55 48 89 f5 53
RSP: 0018:ffffc90000b37d88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88810a234ac0 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffc90000b37df7 RDI: ffff88810a234ac0
RBP: ffffc90000b37df7 R08: ffff88810a1fa410 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888109571000 R14: ffff88810a234ac0 R15: 0000000000000000
FS: 0000000001821380(0000) GS:ffff88846fdc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f74fc550008 CR3: 000000010a6fe000 CR4: 0000000000350ea0
Call Trace:
<TASK>
inject_pending_event+0x2f7/0x4c0 [kvm]
kvm_arch_vcpu_ioctl_run+0x791/0x17a0 [kvm]
kvm_vcpu_ioctl+0x26d/0x650 [kvm]
__x64_sys_ioctl+0x82/0xb0
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
scsi: sg: Allow waiting for commands to complete on removed device
When a SCSI device is removed while in active use, currently sg will
immediately return -ENODEV on any attempt to wait for active commands that
were sent before the removal. This is problematic for commands that use
SG_FLAG_DIRECT_IO since the data buffer may still be in use by the kernel
when userspace frees or reuses it after getting ENODEV, leading to
corrupted userspace memory (in the case of READ-type commands) or corrupted
data being sent to the device (in the case of WRITE-type commands). This
has been seen in practice when logging out of a iscsi_tcp session, where
the iSCSI driver may still be processing commands after the device has been
marked for removal.
Change the policy to allow userspace to wait for active sg commands even
when the device is being removed. Return -ENODEV only when there are no
more responses to read.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18