cbcvebase.
CVE-2024-49980
published 2024-10-21

CVE-2024-49980: In the Linux kernel, the following vulnerability has been resolved: vrf: revert "vrf: Remove unnecessary RCU-bh critical section" This reverts commit…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.18%
7.5th percentile
In the Linux kernel, the following vulnerability has been resolved:

vrf: revert "vrf: Remove unnecessary RCU-bh critical section"

This reverts commit 504fc6f4f7f681d2a03aa5f68aad549d90eab853.

dev_queue_xmit_nit is expected to be called with BH disabled.
__dev_queue_xmit has the following:

/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
rcu_read_lock_bh();

VRF must follow this invariant. The referenced commit removed this
protection. Which triggered a lockdep warning:

WARNING: inconsistent lock state
6.11.0 #1 Tainted: G W
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
btserver/134819 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff8882da30c118 (rlock-AF_PACKET){+.?.}-{2:2}, at: tpacket_rcv+0x863/0x3b30
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
packet_rcv+0xa33/0x1320
__netif_receive_skb_core.constprop.0+0xcb0/0x3a90
__netif_receive_skb_list_core+0x2c9/0x890
netif_receive_skb_list_internal+0x610/0xcc0
[...]

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(rlock-AF_PACKET);

lock(rlock-AF_PACKET);

*** DEADLOCK ***

Call Trace:

dump_stack_lvl+0x73/0xa0
mark_lock+0x102e/0x16b0
__lock_acquire+0x9ae/0x6170
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
tpacket_rcv+0x863/0x3b30
dev_queue_xmit_nit+0x709/0xa40
vrf_finish_direct+0x26e/0x340 [vrf]
vrf_l3_out+0x5f4/0xe80 [vrf]
__ip_local_out+0x51e/0x7a0
[...]

Affected

18 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.11.4-1 (forky)linux 6.11.4-1 (forky)
linuxlinux
linuxlinux>= 504fc6f4f7f681d2a03aa5f68aad549d90eab853 < 718a752bd746b3f4dd62516bb437baf73d548415718a752bd746b3f4dd62516bb437baf73d548415
linuxlinux>= 504fc6f4f7f681d2a03aa5f68aad549d90eab853 < 8c9381b3138246d46536db93ed696832abd702048c9381b3138246d46536db93ed696832abd70204
linuxlinux>= 504fc6f4f7f681d2a03aa5f68aad549d90eab853 < e61f8c4d179b2ffc0d3b7f821c3734be738643d0e61f8c4d179b2ffc0d3b7f821c3734be738643d0
linuxlinux>= 504fc6f4f7f681d2a03aa5f68aad549d90eab853 < b04c4d9eb4f25b950b33218e33b04c94e7445e51b04c4d9eb4f25b950b33218e33b04c94e7445e51
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 6.8.0-54.566.8.0-54.56
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 6.11 < 6.11.36.11.3
linuxlinux_kernel>= 6.6 < 6.6.556.6.55
linuxlinux_kernel>= 6.7 < 6.10.146.10.14
msrcazl3_kernel_6.6.51.1-5_on_azure_linux_3.0
msrcazl3_kernel_6.6.57.1-2_on_azure_linux_3.0
msrcazure_linux_3.0_arm
msrcazure_linux_3.0_x64

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5LOW
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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