In the Linux kernel, the following vulnerability has been resolved:
fs/9p: only translate RWX permissions for plain 9P2000
Garbage in plain 9P2000's perm bits is allowed through, which causes it
to be able to set (among others) the suid bit. This was presumably not
the intent since the unix extended bits are handled explicitly and
conditionally on .u.
In the Linux kernel, the following vulnerability has been resolved:
firewire: ohci: mask bus reset interrupts between ISR and bottom half
In the FireWire OHCI interrupt handler, if a bus reset interrupt has
occurred, mask bus reset interrupts until bus_reset_work has serviced and
cleared the interrupt.
Normally, we always leave bus reset interrupts masked. We infer the bus
reset from the self-ID interrupt that happens shortly thereafter. A
scenario where we unmask bus reset interrupts was introduced in 2008 in
a007bb857e0b26f5d8b73c2ff90782d9c0972620: If
OHCI_PARAM_DEBUG_BUSRESETS (8) is set in the debug parameter bitmask, we
will unmask bus reset interrupts so we can log them.
irq_handler logs the bus reset interrupt. However, we can't clear the bus
reset event flag in irq_handler, because we won't service the event until
later. irq_handler exits with the event flag still set. If the
corresponding interrupt is still unmasked, the first bus reset will
usually freeze the system due to irq_handler being called again each
time it exits. This freeze can be reproduced by loading firewire_ohci
with "modprobe firewire_ohci debug=-1" (to enable all debugging output).
Apparently there are also some cases where bus_reset_work will get called
soon enough to clear the event, and operation will continue normally.
This freeze was first reported a few months after a007bb85 was committed,
but until now it was never fixed. The debug level could safely be set
to -1 through sysfs after the module was loaded, but this would be
ineffectual in logging bus reset interrupts since they were only
unmasked during initialization.
irq_handler will now leave the event flag set but mask bus reset
interrupts, so irq_handler won't be called again and there will be no
freeze. If OHCI_PARAM_DEBUG_BUSRESETS is enabled, bus_reset_work will
unmask the interrupt after servicing the event, so future interrupts
will be caught as desired.
As a side effect to this change, OHCI_PARAM_DEBUG_BUSRESETS can now be
enabled through sysfs in addition to during initial module loading.
However, when enabled through sysfs, logging of bus reset interrupts will
be effective only starting with the second bus reset, after
bus_reset_work has executed.
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic-v2: Check for non-NULL vCPU in vgic_v2_parse_attr()
vgic_v2_parse_attr() is responsible for finding the vCPU that matches
the user-provided CPUID, which (of course) may not be valid. If the ID
is invalid, kvm_get_vcpu_by_id() returns NULL, which isn't handled
gracefully.
Similar to the GICv3 uaccess flow, check that kvm_get_vcpu_by_id()
actually returns something and fail the ioctl if not.
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix a possible memleak in tipc_buf_append
__skb_linearize() doesn't free the skb when it fails, so move
'*buf = NULL' after __skb_linearize(), so that the skb can be
freed on the err path.
In the Linux kernel, the following vulnerability has been resolved:
octeontx2-af: avoid off-by-one read from userspace
We try to access count + 1 byte from userspace with memdup_user(buffer,
count + 1). However, the userspace only provides buffer of count bytes and
only these count bytes are verified to be okay to access. To ensure the
copied buffer is NUL terminated, we use memdup_user_nul instead.
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: core: delete incorrect free in pinctrl_enable()
The "pctldev" struct is allocated in devm_pinctrl_register_and_init().
It's a devm_ managed pointer that is freed by devm_pinctrl_dev_release(),
so freeing it in pinctrl_enable() will lead to a double free.
The devm_pinctrl_dev_release() function frees the pindescs and destroys
the mutex as well.
In the Linux kernel, the following vulnerability has been resolved:
wifi: nl80211: don't free NULL coalescing rule
If the parsing fails, we can dereference a NULL pointer here.
In the Linux kernel, the following vulnerability has been resolved:
phonet: fix rtm_phonet_notify() skb allocation
fill_route() stores three components in the skb:
- struct rtmsg
- RTA_DST (u8)
- RTA_OIF (u32)
Therefore, rtm_phonet_notify() should use
NLMSG_ALIGN(sizeof(struct rtmsg)) +
nla_total_size(1) +
nla_total_size(4)
In the Linux kernel, the following vulnerability has been resolved:
net: core: reject skb_copy(_expand) for fraglist GSO skbs
SKB_GSO_FRAGLIST skbs must not be linearized, otherwise they become
invalid. Return NULL if such an skb is passed to skb_copy or
skb_copy_expand, in order to prevent a crash on a potential later
call to skb_gso_segment.
In the Linux kernel, the following vulnerability has been resolved:
nsh: Restore skb->{protocol,data,mac_header} for outer header in nsh_gso_segment().
syzbot triggered various splats (see [0] and links) by a crafted GSO
packet of VIRTIO_NET_HDR_GSO_UDP layering the following protocols:
ETH_P_8021AD + ETH_P_NSH + ETH_P_IPV6 + IPPROTO_UDP
NSH can encapsulate IPv4, IPv6, Ethernet, NSH, and MPLS. As the inner
protocol can be Ethernet, NSH GSO handler, nsh_gso_segment(), calls
skb_mac_gso_segment() to invoke inner protocol GSO handlers.
nsh_gso_segment() does the following for the original skb before
calling skb_mac_gso_segment()
1. reset skb->network_header
2. save the original skb->{mac_heaeder,mac_len} in a local variable
3. pull the NSH header
4. resets skb->mac_header
5. set up skb->mac_len and skb->protocol for the inner protocol.
and does the following for the segmented skb
6. set ntohs(ETH_P_NSH) to skb->protocol
7. push the NSH header
8. restore skb->mac_header
9. set skb->mac_header + mac_len to skb->network_header
10. restore skb->mac_len
There are two problems in 6-7 and 8-9.
(a)
After 6 & 7, skb->data points to the NSH header, so the outer header
(ETH_P_8021AD in this case) is stripped when skb is sent out of netdev.
Also, if NSH is encapsulated by NSH + Ethernet (so NSH-Ethernet-NSH),
skb_pull() in the first nsh_gso_segment() will make skb->data point
to the middle of the outer NSH or Ethernet header because the Ethernet
header is not pulled by the second nsh_gso_segment().
(b)
While restoring skb->{mac_header,network_header} in 8 & 9,
nsh_gso_segment() does not assume that the data in the linear
buffer is shifted.
However, udp6_ufo_fragment() could shift the data and change
skb->mac_header accordingly as demonstrated by syzbot.
If this happens, even the restored skb->mac_header points to
the middle of the outer header.
It seems nsh_gso_segment() has never worked with outer headers so far.
At the end of nsh_gso_segment(), the outer header must be restored for
the segmented skb, instead of the NSH header.
To do that, let's calculate the outer header position relatively from
the inner header and set skb->{data,mac_header,protocol} properly.
[0]:
BUG: KMSAN: uninit-value in ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:524 [inline]
BUG: KMSAN: uninit-value in ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
BUG: KMSAN: uninit-value in ipvlan_queue_xmit+0xf44/0x16b0 drivers/net/ipvlan/ipvlan_core.c:668
ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:524 [inline]
ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
ipvlan_queue_xmit+0xf44/0x16b0 drivers/net/ipvlan/ipvlan_core.c:668
ipvlan_start_xmit+0x5c/0x1a0 drivers/net/ipvlan/ipvlan_main.c:222
__netdev_start_xmit include/linux/netdevice.h:4989 [inline]
netdev_start_xmit include/linux/netdevice.h:5003 [inline]
xmit_one net/core/dev.c:3547 [inline]
dev_hard_start_xmit+0x244/0xa10 net/core/dev.c:3563
__dev_queue_xmit+0x33ed/0x51c0 net/core/dev.c:4351
dev_queue_xmit include/linux/netdevice.h:3171 [inline]
packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
packet_snd net/packet/af_packet.c:3081 [inline]
packet_sendmsg+0x8aef/0x9f10 net/packet/af_packet.c:3113
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x735/0xa10 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0x125/0x1c0 net/socket.c:2199
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Uninit was created at:
slab_post_alloc_hook mm/slub.c:3819 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc_node_track_caller+0x705/0x1000 mm/slub.c:4001
kmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:582
__
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