In the Linux kernel, the following vulnerability has been resolved:
crypto: af_alg - zero initialize memory allocated via sock_kmalloc
Several crypto user API contexts and requests allocated with
sock_kmalloc() were left uninitialized, relying on callers to
set fields explicitly. This resulted in the use of uninitialized
data in certain error paths or when new fields are added in the
future.
The ACVP patches also contain two user-space interface files:
algif_kpp.c and algif_akcipher.c. These too rely on proper
initialization of their context structures.
A particular issue has been observed with the newly added
'inflight' variable introduced in af_alg_ctx by commit:
67b164a871af ("crypto: af_alg - Disallow multiple in-flight AIO requests")
Because the context is not memset to zero after allocation,
the inflight variable has contained garbage values. As a result,
af_alg_alloc_areq() has incorrectly returned -EBUSY randomly when
the garbage value was interpreted as true:
https://github.com/gregkh/linux/blame/master/crypto/af_alg.c#L1209
The check directly tests ctx->inflight without explicitly
comparing against true/false. Since inflight is only ever set to
true or false later, an uninitialized value has triggered
-EBUSY failures. Zero-initializing memory allocated with
sock_kmalloc() ensures inflight and other fields start in a known
state, removing random issues caused by uninitialized data.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix VM hard lockup after prolonged inactivity with periodic HV timer
When advancing the target expiration for the guest's APIC timer in periodic
mode, set the expiration to "now" if the target expiration is in the past
(similar to what is done in update_target_expiration()). Blindly adding
the period to the previous target expiration can result in KVM generating
a practically unbounded number of hrtimer IRQs due to programming an
expired timer over and over. In extreme scenarios, e.g. if userspace
pauses/suspends a VM for an extended duration, this can even cause hard
lockups in the host.
Currently, the bug only affects Intel CPUs when using the hypervisor timer
(HV timer), a.k.a. the VMX preemption timer. Unlike the software timer,
a.k.a. hrtimer, which KVM keeps running even on exits to userspace, the
HV timer only runs while the guest is active. As a result, if the vCPU
does not run for an extended duration, there will be a huge gap between
the target expiration and the current time the vCPU resumes running.
Because the target expiration is incremented by only one period on each
timer expiration, this leads to a series of timer expirations occurring
rapidly after the vCPU/VM resumes.
More critically, when the vCPU first triggers a periodic HV timer
expiration after resuming, advancing the expiration by only one period
will result in a target expiration in the past. As a result, the delta
may be calculated as a negative value. When the delta is converted into
an absolute value (tscdeadline is an unsigned u64), the resulting value
can overflow what the HV timer is capable of programming. I.e. the large
value will exceed the VMX Preemption Timer's maximum bit width of
cpu_preemption_timer_multi + 32, and thus cause KVM to switch from the
HV timer to the software timer (hrtimers).
After switching to the software timer, periodic timer expiration callbacks
may be executed consecutively within a single clock interrupt handler,
because hrtimers honors KVM's request for an expiration in the past and
immediately re-invokes KVM's callback after reprogramming. And because
the interrupt handler runs with IRQs disabled, restarting KVM's hrtimer
over and over until the target expiration is advanced to "now" can result
in a hard lockup.
E.g. the following hard lockup was triggered in the host when running a
Windows VM (only relevant because it used the APIC timer in periodic mode)
after resuming the VM from a long suspend (in the host).
NMI watchdog: Watchdog detected hard LOCKUP on cpu 45
...
RIP: 0010:advance_periodic_target_expiration+0x4d/0x80 [kvm]
...
RSP: 0018:ff4f88f5d98d8ef0 EFLAGS: 00000046
RAX: fff0103f91be678e RBX: fff0103f91be678e RCX: 00843a7d9e127bcc
RDX: 0000000000000002 RSI: 0052ca4003697505 RDI: ff440d5bfbdbd500
RBP: ff440d5956f99200 R08: ff2ff2a42deb6a84 R09: 000000000002a6c0
R10: 0122d794016332b3 R11: 0000000000000000 R12: ff440db1af39cfc0
R13: ff440db1af39cfc0 R14: ffffffffc0d4a560 R15: ff440db1af39d0f8
FS: 00007f04a6ffd700(0000) GS:ff440db1af380000(0000) knlGS:000000e38a3b8000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000d5651feff8 CR3: 000000684e038002 CR4: 0000000000773ee0
PKRU: 55555554
Call Trace:
<IRQ>
apic_timer_fn+0x31/0x50 [kvm]
__hrtimer_run_queues+0x100/0x280
hrtimer_interrupt+0x100/0x210
? ttwu_do_wakeup+0x19/0x160
smp_apic_timer_interrupt+0x6a/0x130
apic_timer_interrupt+0xf/0x20
</IRQ>
Moreover, if the suspend duration of the virtual machine is not long enough
to trigger a hard lockup in this scenario, since commit 98c25ead5eda
("KVM: VMX: Move preemption timer <=> hrtimer dance to common x86"), KVM
will continue using the software timer until the guest reprograms the APIC
timer in some way. Since the periodic timer does not require frequent APIC
timer register programming, the guest may continue to use the software
timer in
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: Handle incorrect num_connectors capability
The UCSI spec states that the num_connectors field is 7 bits, and the
8th bit is reserved and should be set to zero.
Some buggy FW has been known to set this bit, and it can lead to a
system not booting.
Flag that the FW is not behaving correctly, and auto-fix the value
so that the system boots correctly.
Found on Lenovo P1 G8 during Linux enablement program. The FW will
be fixed, but seemed worth addressing in case it hit platforms that
aren't officially Linux supported.
In the Linux kernel, the following vulnerability has been resolved:
MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits
Since commit e424054000878 ("MIPS: Tracing: Reduce the overhead of
dynamic Function Tracer"), the macro UASM_i_LA_mostly has been used,
and this macro can generate more than 2 instructions. At the same
time, the code in ftrace assumes that no more than 2 instructions can
be generated, which is why it stores them in an int[2] array. However,
as previously noted, the macro UASM_i_LA_mostly (and now UASM_i_LA)
causes a buffer overflow when _mcount is beyond 32 bits. This leads to
corruption of the variables located in the __read_mostly section.
This corruption was observed because the variable
__cpu_primary_thread_mask was corrupted, causing a hang very early
during boot.
This fix prevents the corruption by avoiding the generation of
instructions if they could exceed 2 instructions in
length. Fortunately, insn_la_mcount is only used if the instrumented
code is located outside the kernel code section, so dynamic ftrace can
still be used, albeit in a more limited scope. This is still
preferable to corrupting memory and/or crashing the kernel.
In the Linux kernel, the following vulnerability has been resolved:
e1000: fix OOB in e1000_tbi_should_accept()
In e1000_tbi_should_accept() we read the last byte of the frame via
'data[length - 1]' to evaluate the TBI workaround. If the descriptor-
reported length is zero or larger than the actual RX buffer size, this
read goes out of bounds and can hit unrelated slab objects. The issue
is observed from the NAPI receive path (e1000_clean_rx_irq):
==================================================================
BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790
Read of size 1 at addr ffff888014114e54 by task sshd/363
CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0x5a/0x74
print_address_description+0x7b/0x440
print_report+0x101/0x200
kasan_report+0xc1/0xf0
e1000_tbi_should_accept+0x610/0x790
e1000_clean_rx_irq+0xa8c/0x1110
e1000_clean+0xde2/0x3c10
__napi_poll+0x98/0x380
net_rx_action+0x491/0xa20
__do_softirq+0x2c9/0x61d
do_softirq+0xd1/0x120
</IRQ>
<TASK>
__local_bh_enable_ip+0xfe/0x130
ip_finish_output2+0x7d5/0xb00
__ip_queue_xmit+0xe24/0x1ab0
__tcp_transmit_skb+0x1bcb/0x3340
tcp_write_xmit+0x175d/0x6bd0
__tcp_push_pending_frames+0x7b/0x280
tcp_sendmsg_locked+0x2e4f/0x32d0
tcp_sendmsg+0x24/0x40
sock_write_iter+0x322/0x430
vfs_write+0x56c/0xa60
ksys_write+0xd1/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f511b476b10
Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24
RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10
RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003
RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00
R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003
</TASK>
Allocated by task 1:
__kasan_krealloc+0x131/0x1c0
krealloc+0x90/0xc0
add_sysfs_param+0xcb/0x8a0
kernel_add_sysfs_param+0x81/0xd4
param_sysfs_builtin+0x138/0x1a6
param_sysfs_init+0x57/0x5b
do_one_initcall+0x104/0x250
do_initcall_level+0x102/0x132
do_initcalls+0x46/0x74
kernel_init_freeable+0x28f/0x393
kernel_init+0x14/0x1a0
ret_from_fork+0x22/0x30
The buggy address belongs to the object at ffff888014114000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1620 bytes to the right of
2048-byte region [ffff888014114000, ffff888014114800]
The buggy address belongs to the physical page:
page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110
head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x100000000010200(slab|head|node=0|zone=1)
raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
==================================================================
This happens because the TBI check unconditionally dereferences the last
byte without validating the reported length first:
u8 last_byte = *(data + length - 1);
Fix by rejecting the frame early if the length is zero, or if it exceeds
adapter->rx_buffer_len. This preserves the TBI workaround semantics for
valid frames and prevents touching memory beyond the RX buffer.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Check for the presence of LS_NLA_TYPE_DGID correctly
The netlink response for RDMA_NL_LS_OP_IP_RESOLVE should always have a
LS_NLA_TYPE_DGID attribute, it is invalid if it does not.
Use the nl parsing logic properly and call nla_parse_deprecated() to fill
the nlattrs array and then directly index that array to get the data for
the DGID. Just fail if it is NULL.
Remove the for loop searching for the nla, and squash the validation and
parsing into one function.
Fixes an uninitialized read from the stack triggered by userspace if it
does not provide the DGID to a kernel initiated RDMA_NL_LS_OP_IP_RESOLVE
query.
BUG: KMSAN: uninit-value in hex_byte_pack include/linux/hex.h:13 [inline]
BUG: KMSAN: uninit-value in ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
hex_byte_pack include/linux/hex.h:13 [inline]
ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
ip6_addr_string+0x18a/0x3e0 lib/vsprintf.c:1509
ip_addr_string+0x245/0xee0 lib/vsprintf.c:1633
pointer+0xc09/0x1bd0 lib/vsprintf.c:2542
vsnprintf+0xf8a/0x1bd0 lib/vsprintf.c:2930
vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2279
vprintk_emit+0x307/0xcd0 kernel/printk/printk.c:2426
vprintk_default+0x3f/0x50 kernel/printk/printk.c:2465
vprintk+0x36/0x50 kernel/printk/printk_safe.c:82
_printk+0x17e/0x1b0 kernel/printk/printk.c:2475
ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:128 [inline]
ib_nl_handle_ip_res_resp+0x963/0x9d0 drivers/infiniband/core/addr.c:141
rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x333/0x3d0 net/socket.c:729
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2617
___sys_sendmsg+0x271/0x3b0 net/socket.c:2671
__sys_sendmsg+0x1aa/0x300 net/socket.c:2703
__compat_sys_sendmsg net/compat.c:346 [inline]
__do_compat_sys_sendmsg net/compat.c:353 [inline]
__se_compat_sys_sendmsg net/compat.c:350 [inline]
__ia32_compat_sys_sendmsg+0xa4/0x100 net/compat.c:350
ia32_sys_call+0x3f6c/0x4310 arch/x86/include/generated/asm/syscalls_32.h:371
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:3
In the Linux kernel, the following vulnerability has been resolved:
ip6_gre: make ip6gre_header() robust
Over the years, syzbot found many ways to crash the kernel
in ip6gre_header() [1].
This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len
In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ip6gre device.
[1]
skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:213 !
<TASK>
skb_under_panic net/core/skbuff.c:223 [inline]
skb_push+0xc3/0xe0 net/core/skbuff.c:2641
ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371
dev_hard_header include/linux/netdevice.h:3436 [inline]
neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
neigh_output include/net/neighbour.h:556 [inline]
ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136
__ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
In the Linux kernel, the following vulnerability has been resolved:
ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()
There exists a kernel oops caused by a BUG_ON(nhead < 0) at
net/core/skbuff.c:2232 in pskb_expand_head().
This bug is triggered as part of the calipso_skbuff_setattr()
routine when skb_cow() is passed headroom > INT_MAX
(i.e. (int)(skb_headroom(skb) + len_delta) < 0).
The root cause of the bug is due to an implicit integer cast in
__skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure
that delta = headroom - skb_headroom(skb) is never negative, otherwise
we will trigger a BUG_ON in pskb_expand_head(). However, if
headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta
becomes negative, and pskb_expand_head() is passed a negative value for
nhead.
Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing
"negative" headroom sizes to skb_cow() within calipso_skbuff_setattr()
by only using skb_cow() to grow headroom.
PoC:
Using `netlabelctl` tool:
netlabelctl map del default
netlabelctl calipso add pass doi:7
netlabelctl map add default address:0::1/128 protocol:calipso,7
Then run the following PoC:
int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
// setup msghdr
int cmsg_size = 2;
int cmsg_len = 0x60;
struct msghdr msg;
struct sockaddr_in6 dest_addr;
struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,
sizeof(struct cmsghdr) + cmsg_len);
msg.msg_name = &dest_addr;
msg.msg_namelen = sizeof(dest_addr);
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
msg.msg_control = cmsg;
msg.msg_controllen = cmsg_len;
msg.msg_flags = 0;
// setup sockaddr
dest_addr.sin6_family = AF_INET6;
dest_addr.sin6_port = htons(31337);
dest_addr.sin6_flowinfo = htonl(31337);
dest_addr.sin6_addr = in6addr_loopback;
dest_addr.sin6_scope_id = 31337;
// setup cmsghdr
cmsg->cmsg_len = cmsg_len;
cmsg->cmsg_level = IPPROTO_IPV6;
cmsg->cmsg_type = IPV6_HOPOPTS;
char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);
hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80
sendmsg(fd, &msg, 0);
In the Linux kernel, the following vulnerability has been resolved:
iavf: fix off-by-one issues in iavf_config_rss_reg()
There are off-by-one bugs when configuring RSS hash key and lookup
table, causing out-of-bounds reads to memory [1] and out-of-bounds
writes to device registers.
Before commit 43a3d9ba34c9 ("i40evf: Allow PF driver to configure RSS"),
the loop upper bounds were:
i <= I40E_VFQF_{HKEY,HLUT}_MAX_INDEX
which is safe since the value is the last valid index.
That commit changed the bounds to:
i <= adapter->rss_{key,lut}_size / 4
where `rss_{key,lut}_size / 4` is the number of dwords, so the last
valid index is `(rss_{key,lut}_size / 4) - 1`. Therefore, using `<=`
accesses one element past the end.
Fix the issues by using `<` instead of `<=`, ensuring we do not exceed
the bounds.
[1] KASAN splat about rss_key_size off-by-one
BUG: KASAN: slab-out-of-bounds in iavf_config_rss+0x619/0x800
Read of size 4 at addr ffff888102c50134 by task kworker/u8:6/63
CPU: 0 UID: 0 PID: 63 Comm: kworker/u8:6 Not tainted 6.18.0-rc2-enjuk-tnguy-00378-g3005f5b77652-dirty #156 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: iavf iavf_watchdog_task
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xb0
print_report+0x170/0x4f3
kasan_report+0xe1/0x1a0
iavf_config_rss+0x619/0x800
iavf_watchdog_task+0x2be7/0x3230
process_one_work+0x7fd/0x1420
worker_thread+0x4d1/0xd40
kthread+0x344/0x660
ret_from_fork+0x249/0x320
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 63:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
__kmalloc_noprof+0x246/0x6f0
iavf_watchdog_task+0x28fc/0x3230
process_one_work+0x7fd/0x1420
worker_thread+0x4d1/0xd40
kthread+0x344/0x660
ret_from_fork+0x249/0x320
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff888102c50100
which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes to the right of
allocated 52-byte region [ffff888102c50100, ffff888102c50134)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x102c50
flags: 0x200000000000000(node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000000 ffff8881000418c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888102c50000: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
ffff888102c50080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
>ffff888102c50100: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc
^
ffff888102c50180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
ffff888102c50200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc