Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
ipv4: Fix uninit-value access in __ip_make_skb()
KMSAN reported uninit-value access in __ip_make_skb() [1]. __ip_make_skb()
tests HDRINCL to know if the skb has icmphdr. However, HDRINCL can cause a
race condition. If calling setsockopt(2) with IP_HDRINCL changes HDRINCL
while __ip_make_skb() is running, the function will access icmphdr in the
skb even if it is not included. This causes the issue reported by KMSAN.
Check FLOWI_FLAG_KNOWN_NH on fl4->flowi4_flags instead of testing HDRINCL
on the socket.
Also, fl4->fl4_icmp_type and fl4->fl4_icmp_code are not initialized. These
are union in struct flowi4 and are implicitly initialized by
flowi4_init_output(), but we should not rely on specific union layout.
Initialize these explicitly in raw_sendmsg().
[1]
BUG: KMSAN: uninit-value in __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
__ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
ip_finish_skb include/net/ip.h:243 [inline]
ip_push_pending_frames+0x4c/0x5c0 net/ipv4/ip_output.c:1508
raw_sendmsg+0x2381/0x2690 net/ipv4/raw.c:654
inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x274/0x3c0 net/socket.c:745
__sys_sendto+0x62c/0x7b0 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0x130/0x200 net/socket.c:2199
do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
Uninit was created at:
slab_post_alloc_hook mm/slub.c:3804 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc_node+0x5f6/0xc50 mm/slub.c:3888
kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:577
__alloc_skb+0x35a/0x7c0 net/core/skbuff.c:668
alloc_skb include/linux/skbuff.h:1318 [inline]
__ip_append_data+0x49ab/0x68c0 net/ipv4/ip_output.c:1128
ip_append_data+0x1e7/0x260 net/ipv4/ip_output.c:1365
raw_sendmsg+0x22b1/0x2690 net/ipv4/raw.c:648
inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x274/0x3c0 net/socket.c:745
__sys_sendto+0x62c/0x7b0 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0x130/0x200 net/socket.c:2199
do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
CPU: 1 PID: 15709 Comm: syz-executor.7 Not tainted 6.8.0-11567-gb3603fcb79b1 #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
In the Linux kernel, the following vulnerability has been resolved:
uio_hv_generic: Don't free decrypted memory
In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
The VMBus device UIO driver could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the gpadl
to decide whether to free the memory.
In the Linux kernel, the following vulnerability has been resolved:
Drivers: hv: vmbus: Track decrypted status in vmbus_gpadl
In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
In order to make sure callers of vmbus_establish_gpadl() and
vmbus_teardown_gpadl() don't return decrypted/shared pages to
allocators, add a field in struct vmbus_gpadl to keep track of the
decryption status of the buffers. This will allow the callers to
know if they should free or leak the pages.
In the Linux kernel, the following vulnerability has been resolved:
Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails
In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
VMBus code could free decrypted pages if set_memory_encrypted()/decrypted()
fails. Leak the pages if this happens.
In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix access violation during port device removal
Testing with KASAN and syzkaller revealed a bug in port.c:disable_store():
usb_hub_to_struct_hub() can return NULL if the hub that the port belongs to
is concurrently removed, but the function does not check for this
possibility before dereferencing the returned value.
It turns out that the first dereference is unnecessary, since hub->intfdev
is the parent of the port device, so it can be changed easily. Adding a
check for hub == NULL prevents further problems.
The same bug exists in the disable_show() routine, and it can be fixed the
same way.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Atom Integrated System Info v2_2 for DCN35
New request from KMD/VBIOS in order to support new UMA carveout
model. This fixes a null dereference from accessing
Ctx->dc_bios->integrated_info while it was NULL.
DAL parses through the BIOS and extracts the necessary
integrated_info but was missing a case for the new BIOS
version 2.3.
In the Linux kernel, the following vulnerability has been resolved:
gpiolib: cdev: Fix use after free in lineinfo_changed_notify
The use-after-free issue occurs as follows: when the GPIO chip device file
is being closed by invoking gpio_chrdev_release(), watched_lines is freed
by bitmap_free(), but the unregistration of lineinfo_changed_nb notifier
chain failed due to waiting write rwsem. Additionally, one of the GPIO
chip's lines is also in the release process and holds the notifier chain's
read rwsem. Consequently, a race condition leads to the use-after-free of
watched_lines.
Here is the typical stack when issue happened:
[free]
gpio_chrdev_release()
--> bitmap_free(cdev->watched_lines) <-- freed
--> blocking_notifier_chain_unregister()
--> down_write(&nh->rwsem) <-- waiting rwsem
--> __down_write_common()
--> rwsem_down_write_slowpath()
--> schedule_preempt_disabled()
--> schedule()
[use]
st54spi_gpio_dev_release()
--> gpio_free()
--> gpiod_free()
--> gpiod_free_commit()
--> gpiod_line_state_notify()
--> blocking_notifier_call_chain()
--> down_read(&nh->rwsem); <-- held rwsem
--> notifier_call_chain()
--> lineinfo_changed_notify()
--> test_bit(xxxx, cdev->watched_lines) <-- use after free
The side effect of the use-after-free issue is that a GPIO line event is
being generated for userspace where it shouldn't. However, since the chrdev
is being closed, userspace won't have the chance to read that event anyway.
To fix the issue, call the bitmap_free() function after the unregistration
of lineinfo_changed_nb notifier chain.
In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent NULL dereference in ip6_output()
According to syzbot, there is a chance that ip6_dst_idev()
returns NULL in ip6_output(). Most places in IPv6 stack
deal with a NULL idev just fine, but not here.
syzbot reported:
general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 9775 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00157-g6a30653b604a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:ip6_output+0x231/0x3f0 net/ipv6/ip6_output.c:237
Code: 3c 1e 00 49 89 df 74 08 4c 89 ef e8 19 58 db f7 48 8b 44 24 20 49 89 45 00 49 89 c5 48 8d 9d e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 4c 8b 74 24 28 0f 85 61 01 00 00 8b 1b 31 ff
RSP: 0018:ffffc9000927f0d8 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000040000
RDX: ffffc900131f9000 RSI: 0000000000004f47 RDI: 0000000000004f48
RBP: 0000000000000000 R08: ffffffff8a1f0b9a R09: 1ffffffff1f51fad
R10: dffffc0000000000 R11: fffffbfff1f51fae R12: ffff8880293ec8c0
R13: ffff88805d7fc000 R14: 1ffff1100527d91a R15: dffffc0000000000
FS: 00007f135c6856c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 0000000064096000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
NF_HOOK include/linux/netfilter.h:314 [inline]
ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358
sctp_v6_xmit+0x9f2/0x13f0 net/sctp/ipv6.c:248
sctp_packet_transmit+0x26ad/0x2ca0 net/sctp/output.c:653
sctp_packet_singleton+0x22c/0x320 net/sctp/outqueue.c:783
sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
sctp_outq_flush+0x6d5/0x3e20 net/sctp/outqueue.c:1212
sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
sctp_do_sm+0x59cc/0x60c0 net/sctp/sm_sideeffect.c:1169
sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73
__sctp_connect+0x9cd/0xe30 net/sctp/socket.c:1234
sctp_connect net/sctp/socket.c:4819 [inline]
sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834
__sys_connect_file net/socket.c:2048 [inline]
__sys_connect+0x2df/0x310 net/socket.c:2065
__do_sys_connect net/socket.c:2075 [inline]
__se_sys_connect net/socket.c:2072 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2072
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action()
syzbot is able to trigger the following crash [1],
caused by unsafe ip6_dst_idev() use.
Indeed ip6_dst_idev() can return NULL, and must always be checked.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 31648 Comm: syz-executor.0 Not tainted 6.9.0-rc4-next-20240417-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__fib6_rule_action net/ipv6/fib6_rules.c:237 [inline]
RIP: 0010:fib6_rule_action+0x241/0x7b0 net/ipv6/fib6_rules.c:267
Code: 02 00 00 49 8d 9f d8 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f9 32 bf f7 48 8b 1b 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 e0 32 bf f7 4c 8b 03 48 89 ef 4c
RSP: 0018:ffffc9000fc1f2f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1a772f98c8186700
RDX: 0000000000000003 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f9760
RBP: ffff8880673fb980 R08: ffffffff8fac15ef R09: 1ffffffff1f582bd
R10: dffffc0000000000 R11: fffffbfff1f582be R12: dffffc0000000000
R13: 0000000000000080 R14: ffff888076509000 R15: ffff88807a029a00
FS: 00007f55e82ca6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d23000 CR3: 0000000022b66000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
fib_rules_lookup+0x62c/0xdb0 net/core/fib_rules.c:317
fib6_rule_lookup+0x1fd/0x790 net/ipv6/fib6_rules.c:108
ip6_route_output_flags_noref net/ipv6/route.c:2637 [inline]
ip6_route_output_flags+0x38e/0x610 net/ipv6/route.c:2649
ip6_route_output include/net/ip6_route.h:93 [inline]
ip6_dst_lookup_tail+0x189/0x11a0 net/ipv6/ip6_output.c:1120
ip6_dst_lookup_flow+0xb9/0x180 net/ipv6/ip6_output.c:1250
sctp_v6_get_dst+0x792/0x1e20 net/sctp/ipv6.c:326
sctp_transport_route+0x12c/0x2e0 net/sctp/transport.c:455
sctp_assoc_add_peer+0x614/0x15c0 net/sctp/associola.c:662
sctp_connect_new_asoc+0x31d/0x6c0 net/sctp/socket.c:1099
__sctp_connect+0x66d/0xe30 net/sctp/socket.c:1197
sctp_connect net/sctp/socket.c:4819 [inline]
sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834
__sys_connect_file net/socket.c:2048 [inline]
__sys_connect+0x2df/0x310 net/socket.c:2065
__do_sys_connect net/socket.c:2075 [inline]
__se_sys_connect net/socket.c:2072 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2072
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
In the Linux kernel, the following vulnerability has been resolved:
ipv6: Fix potential uninit-value access in __ip6_make_skb()
As it was done in commit fc1092f51567 ("ipv4: Fix uninit-value access in
__ip_make_skb()") for IPv4, check FLOWI_FLAG_KNOWN_NH on fl6->flowi6_flags
instead of testing HDRINCL on the socket to avoid a race condition which
causes uninit-value access.