In the Linux kernel, the following vulnerability has been resolved:
netfilter: br_netfilter: fix panic with metadata_dst skb
Fix a kernel panic in the br_netfilter module when sending untagged
traffic via a VxLAN device.
This happens during the check for fragmentation in br_nf_dev_queue_xmit.
It is dependent on:
1) the br_netfilter module being loaded;
2) net.bridge.bridge-nf-call-iptables set to 1;
3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port;
4) untagged frames with size higher than the VxLAN MTU forwarded/flooded
When forwarding the untagged packet to the VxLAN bridge port, before
the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and
changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type
of dst, i.e., skb_valid_dst(skb) is false, and metadata->dst.dev is NULL.
Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check
for frames that needs to be fragmented: frames with higher MTU than the
VxLAN device end up calling br_nf_ip_fragment, which in turns call
ip_skb_dst_mtu.
The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst
with valid dst->dev, thus the crash.
This case was never supported in the first place, so drop the packet
instead.
PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data.
[ 176.291791] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000110
[ 176.292101] Mem abort info:
[ 176.292184] ESR = 0x0000000096000004
[ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits
[ 176.292530] SET = 0, FnV = 0
[ 176.292709] EA = 0, S1PTW = 0
[ 176.292862] FSC = 0x04: level 0 translation fault
[ 176.293013] Data abort info:
[ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000
[ 176.294166] [0000000000000110] pgd=0000000000000000,
p4d=0000000000000000
[ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth
br_netfilter bridge stp llc ipv6 crct10dif_ce
[ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted
6.8.0-rc3-g5b3fbd61b9d1 #2
[ 176.296314] Hardware name: linux,dummy-virt (DT)
[ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter]
[ 176.297636] sp : ffff800080003630
[ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27:
ffff6828c49ad9f8
[ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24:
00000000000003e8
[ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21:
ffff6828c3b16d28
[ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18:
0000000000000014
[ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15:
0000000095744632
[ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12:
ffffb7e137926a70
[ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 :
0000000000000000
[ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 :
f20e0100bebafeca
[ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 :
0000000000000000
[ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 :
ffff6828c7f918f0
[ 176.300889] Call trace:
[ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter]
[ 176.301703] nf_hook_slow+0x48/0x124
[ 176.302060] br_forward_finish+0xc8/0xe8 [bridge]
[ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter]
[ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter]
[ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter]
[ 176.303359] nf_hook_slow+0x48/0x124
[ 176.303
---truncated---
Metrics
Affected Vendors & Products
References
History
Fri, 08 Nov 2024 16:15:00 +0000
Type | Values Removed | Values Added |
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References |
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Thu, 24 Oct 2024 20:00:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | CWE-476 | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* |
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Vendors & Products |
Linux
Linux linux Kernel |
Tue, 22 Oct 2024 14:15:00 +0000
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Metrics |
ssvc
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Tue, 22 Oct 2024 13:30:00 +0000
Type | Values Removed | Values Added |
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References |
| |
Metrics |
threat_severity
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cvssV3_1
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Mon, 21 Oct 2024 19:45:00 +0000
Type | Values Removed | Values Added |
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Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: br_netfilter: fix panic with metadata_dst skb Fix a kernel panic in the br_netfilter module when sending untagged traffic via a VxLAN device. This happens during the check for fragmentation in br_nf_dev_queue_xmit. It is dependent on: 1) the br_netfilter module being loaded; 2) net.bridge.bridge-nf-call-iptables set to 1; 3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port; 4) untagged frames with size higher than the VxLAN MTU forwarded/flooded When forwarding the untagged packet to the VxLAN bridge port, before the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type of dst, i.e., skb_valid_dst(skb) is false, and metadata->dst.dev is NULL. Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check for frames that needs to be fragmented: frames with higher MTU than the VxLAN device end up calling br_nf_ip_fragment, which in turns call ip_skb_dst_mtu. The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst with valid dst->dev, thus the crash. This case was never supported in the first place, so drop the packet instead. PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data. [ 176.291791] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000110 [ 176.292101] Mem abort info: [ 176.292184] ESR = 0x0000000096000004 [ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits [ 176.292530] SET = 0, FnV = 0 [ 176.292709] EA = 0, S1PTW = 0 [ 176.292862] FSC = 0x04: level 0 translation fault [ 176.293013] Data abort info: [ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000 [ 176.294166] [0000000000000110] pgd=0000000000000000, p4d=0000000000000000 [ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth br_netfilter bridge stp llc ipv6 crct10dif_ce [ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted 6.8.0-rc3-g5b3fbd61b9d1 #2 [ 176.296314] Hardware name: linux,dummy-virt (DT) [ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter] [ 176.297636] sp : ffff800080003630 [ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27: ffff6828c49ad9f8 [ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24: 00000000000003e8 [ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21: ffff6828c3b16d28 [ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18: 0000000000000014 [ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15: 0000000095744632 [ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12: ffffb7e137926a70 [ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 : 0000000000000000 [ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 : f20e0100bebafeca [ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 : 0000000000000000 [ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 : ffff6828c7f918f0 [ 176.300889] Call trace: [ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter] [ 176.301703] nf_hook_slow+0x48/0x124 [ 176.302060] br_forward_finish+0xc8/0xe8 [bridge] [ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter] [ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter] [ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter] [ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter] [ 176.303359] nf_hook_slow+0x48/0x124 [ 176.303 ---truncated--- | |
Title | netfilter: br_netfilter: fix panic with metadata_dst skb | |
References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-10-21T19:39:43.117Z
Updated: 2024-11-19T01:15:09.353Z
Reserved: 2024-10-21T12:17:06.071Z
Link: CVE-2024-50045
Vulnrichment
Updated: 2024-10-22T13:24:18.789Z
NVD
Status : Modified
Published: 2024-10-21T20:15:17.373
Modified: 2024-11-08T16:15:44.813
Link: CVE-2024-50045
Redhat