// For flags

CVE-2024-35888

erspan: make sure erspan_base_hdr is present in skb->head

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

erspan: make sure erspan_base_hdr is present in skb->head

syzbot reported a problem in ip6erspan_rcv() [1]

Issue is that ip6erspan_rcv() (and erspan_rcv()) no longer make
sure erspan_base_hdr is present in skb linear part (skb->head)
before getting @ver field from it.

Add the missing pskb_may_pull() calls.

v2: Reload iph pointer in erspan_rcv() after pskb_may_pull()
because skb->head might have changed.

[1]

BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]
BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2756 [inline]
BUG: KMSAN: uninit-value in ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]
BUG: KMSAN: uninit-value in gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610
pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]
pskb_may_pull include/linux/skbuff.h:2756 [inline]
ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]
gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610
ip6_protocol_deliver_rcu+0x1d4c/0x2ca0 net/ipv6/ip6_input.c:438
ip6_input_finish net/ipv6/ip6_input.c:483 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492
ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586
dst_input include/net/dst.h:460 [inline]
ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:314 [inline]
ipv6_rcv+0xde/0x390 net/ipv6/ip6_input.c:310
__netif_receive_skb_one_core net/core/dev.c:5538 [inline]
__netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652
netif_receive_skb_internal net/core/dev.c:5738 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5798
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2108 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb63/0x1520 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xe0 fs/read_write.c:652
do_syscall_64+0xd5/0x1f0
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+0x613/0xc50 mm/slub.c:3888
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577
__alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668
alloc_skb include/linux/skbuff.h:1318 [inline]
alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504
sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795
tun_alloc_skb drivers/net/tun.c:1525 [inline]
tun_get_user+0x209a/0x69e0 drivers/net/tun.c:1846
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2108 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb63/0x1520 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xe0 fs/read_write.c:652
do_syscall_64+0xd5/0x1f0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 5045 Comm: syz-executor114 Not tainted 6.9.0-rc1-syzkaller-00021-g962490525cff #0

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: erspan: asegúrese de que erspan_base_hdr esté presente en skb->head syzbot informó un problema en ip6erspan_rcv() [1] El problema es que ip6erspan_rcv() (y erspan_rcv()) ya no funcionan asegúrese de que erspan_base_hdr esté presente en la parte lineal de skb (skb->head) antes de obtener el campo @ver. Agregue las llamadas pskb_may_pull() que faltan. v2: Vuelva a cargar el puntero iph en erspan_rcv() después de pskb_may_pull() porque skb->head podría haber cambiado. [1] ERROR: KMSAN: valor uninit en pskb_may_pull_reason include/linux/skbuff.h:2742 [en línea] ERROR: KMSAN: valor uninit en pskb_may_pull include/linux/skbuff.h:2756 [en línea] ERROR: KMSAN: uninit -valor en ip6erspan_rcv net/ipv6/ip6_gre.c:541 [en línea] ERROR: KMSAN: valor uninit en gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610 pskb_may_pull_reason include/linux/skbuff.h:2742 [en línea ] PSKB_MAY_PULL incluye/linux/skbuff.h: 2756 [en línea] ip6erspan_rcv net/ipv6/ip6_gre.c: 541 [inline] gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c: 610 ip6_protocol_reLiver+0x1d4cu 6/ ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [en línea] NF_HOOK include/linux/netfilter.h:314 [en línea] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:460 [en línea] ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [en línea] ipv6_rcv +0xde/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5538 [en línea] __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652 netif_receive_skb_internal net/core/dev.c:5738 [en línea] netif_receive_skb+0x58/0x660 net/core/dev.c:5798 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549 tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [en línea] new_sync_write fs/read_write.c:497 [en línea] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [en línea] __se_sys_write fs/read_write.c:652 [en línea] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 entrada_SYSCALL_64 _después_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+0x613/0xc50 mm/slub.c:3888 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff .c:577 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [en línea] alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1525 [en línea] tun_get_user+0x209a/0x69e0 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [en línea] new_sync_write fs/read_write.c:497 [en línea] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs /read_write.c:655 [en línea] __se_sys_write fs/read_write.c:652 [en línea] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 Entry_SYSCALL_64_after_hwframe+0x6d/0x75 CPU: 1 Comunicación 5045: syz-executor114 No contaminado 6.9.0-rc1-syzkaller-00021-g962490525cff #0

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-17 CVE Reserved
  • 2024-05-19 CVE Published
  • 2024-05-20 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19.20 < 4.19.312
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19.20 < 4.19.312"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 5.4.274
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.4.274"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 5.10.215
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.10.215"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 5.15.154
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.15.154"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.1.85
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.1.85"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.6.26
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.6.26"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.8.5
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.8.5"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.9"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
4.20.7
Search vendor "Linux" for product "Linux Kernel" and version "4.20.7"
en
Affected